Lightweight structural member based on composite material, and container ship cell guide structure comprising same

Abstract

Disclosed is a lightweight structural member based on a composite material, the structural member comprising: a first main plate; a second main plate disposed to be spaced a predetermined interval from the first main plate; a plurality of reinforcing plates which are arranged between the first main plate and the second main plate, and which have one or more bent parts; and core layers formed in the space between the first main plate and the reinforcing plate, the space between the second main plate and the reinforcing plate, and the space between the reinforcing plates that are adjacent to each other, wherein a plurality of column parts formed by the bent parts that are adjacent to each other and the core layers formed therebetween are formed at predetermined intervals so as to function as a plate stiffener.

Description

Lightweight structural materials based on composite materials and cell guide structures for container ships containing the same

[0001] The present invention relates to a lightweight structural material based on a composite material and a cell guide structure of a container ship including the same, and more specifically, to a lightweight structural material based on a composite material and a cell guide structure of a container ship including the same, which is manufactured by integrating metal and polymer as main materials and plate reinforcement for structural reinforcement, so that the problem of thermal deformation due to welding does not occur, and equivalent structural performance can be realized while significantly reducing weight compared to existing structures, and furthermore, can be manufactured by integrating longitudinal strength members together.

[0002] Typically, ship structural materials are primarily made of single-material steel plate. The structure of a conventional steel plate structural material is illustrated in Figures 1 and 2.

[0003] Referring to Fig. 1, a conventional steel plate structural material is manufactured in a form in which a metal plate reinforcing material (20) is welded to the lower surface of a metal top plate (10) to reinforce the structure.

[0004] Also, referring to Fig. 2, conventional steel plate structural materials are manufactured in a form in which an upper plate (10) and a lower plate (30) made of metal are arranged facing each other with a certain distance between them, and a plate reinforcing member (20) made of metal is connected therebetween by welding to reinforce the structure. The structure illustrated in Fig. 2 is called a box type structure in that a hexahedral-shaped empty space is formed inside.

[0005] The conventional steel plate structural material as described above is manufactured by first joining a metal plate that serves as the upper plate (10) and then welding a plate reinforcement material (20) for longitudinal strength reinforcement thereon at intervals of 500 to 900 mm between frames (in the case of FIG. 1), or joining metal plates that serve as the upper plate (10) and the lower plate (30) and then welding a plate reinforcement material (20) for longitudinal strength reinforcement therebetween at intervals of 500 to 900 mm between frames (in the case of FIG. 2).

[0006] However, the method of joining plate reinforcement (20) by welding at close intervals, as in the prior art, has the following problems.

[0007] (1) Thermal deformation problem due to welding

[0008] The most critical problem is thermal deformation caused by welding. When welding plate reinforcement (20), the welding area is heated to approximately 1,000 to 1,500°C, and significant stress and deformation occur as the heated steel plate cools. As a result, after welding the plate reinforcement (20), a deviation of several tens of millimeters (mm) per meter (m) is inevitable across the entire plate. Consequently, subsequent correction of this distortion incurs significant time and cost.

[0009] In particular, in the case of structural materials to be used for car decks of PCC (Pure Car Carrier) ships or walls of ship accommodations, thin plates with a top plate thickness of approximately 6 to 10 mm are required. However, in cases where the structure is formed with such a thin thickness, problems due to welding deformation occur much more significantly, such as the top plate itself being torn due to welding deformation or being severely warped to the point where it cannot be corrected by a subsequent correction process.

[0010] Currently, to prevent the above problems from occurring, we are simply using a top plate that is much thicker than the structurally required thickness, or performing a post-process to compensate for thermal deformation at great expense and time, but a more fundamental solution is needed.

[0011] Meanwhile, laser welding is a welding method known to have significantly less thermal distortion than arc welding or gas welding, which are commonly used in shipbuilding. Laser welding focuses light energy from a laser source onto the workpiece, melting the base material and joining it. However, laser welding has limitations in generating sufficient power to melt the base material, and its welding speed and weldable thickness are affected by the metal's thermal conductivity and surface vaporization. Therefore, when applied to thick base materials, welding efficiency is significantly reduced.

[0012] While laser welding is generally known to be possible even for thicknesses greater than 6mm, in reality, the speed of laser welding significantly slows down when the thickness exceeds 4mm. Therefore, laser welding is generally applied primarily to base metals less than 3mm thick. Consequently, laser welding is not easily applied to 6mm steel plates, which are typically considered the thinnest structure in shipbuilding. Furthermore, melting a 6mm-thick steel plate requires significant energy, and even then, the relatively large weld area cools, resulting in similar weld deformation, rendering the method largely ineffective.

[0013] (2) Difficulty in producing box-shaped structures

[0014] The box-shaped plate-reinforced structure illustrated in Fig. 2 is a structure in which vertical reinforcements are connected between two main plates. Since the load is evenly distributed by the two wide main plates, it is a very effective structure that can withstand the same load with 10-30% less weight than a typical plate-reinforced structure. In addition, since the plate reinforcements are not exposed to the outside and are finished with a flat main plate, it is a structure that can significantly increase the automatic welding rate when welding longitudinal and transverse strength members that are attached later.

[0015] However, despite its many advantages, this box-shaped structure is not widely used except in special structures due to its difficult manufacturing process.

[0016] For example, if a general plate reinforcement structure (Fig. 1) having a spacing of approximately 600 to 900 mm and a height of 100 to 400 mm is changed to a box-shaped plate reinforcement structure (Fig. 2), the plate reinforcement (20) can be manufactured at a lower height due to structural optimality.

[0017] At this time, as shown in Fig. 3, the first main plate, in which the plate reinforcement (20) is first joined among the upper plate (10) and the lower plate (20), can be welded in the same manner as a general plate reinforcement structure, but in the case of the second main plate, which is joined later, it is difficult to secure a working space, making the welding work very difficult.

[0018] In other words, it is virtually impossible for a person or an automated machine to weld along the length of a long main plate in a space with a height of only 100 to 400 mm in a conventional manner. Therefore, a very special welding machine must be employed, or the secondary main plate must be cut into small pieces at intervals corresponding to the plate reinforcement (20) and welded to the plate reinforcement (20) individually, resulting in inconveniences.

[0019] If the secondary plate is split into small pieces and welded individually to the plate reinforcement (20), fillet welding is impossible, resulting in a significantly longer work time. Furthermore, the longer the work time, the greater the amount of welding heat input, which can exacerbate the problem of thermal deformation described above. Additional straightening work may be required to straighten the deformed plate.

[0020] (3) Weight problem

[0021] Another drawback of conventional steel plate structures is their excessive weight. While the steel plate structures primarily used in ships are significantly lighter than reinforced concrete used in construction, the growing importance of eco-friendly ships, cost reduction, and labor savings have made "ship lightweighting" a global hot topic in the shipbuilding and marine industries. A reduced ship weight reduces the energy required for propulsion, thereby reducing carbon emissions.

[0022] Furthermore, reducing the weight of a ship is crucial for ensuring stability. For example, multi-deck car carriers (PCCs) suffer from significant stability degradation due to the deck weight itself shifting the ship's center of gravity upward. Therefore, reducing the deck weight is paramount in achieving weight reduction.

[0023] (4) Problem of low usability as a building structural material

[0024] Conventional steel plate structural materials, as described above, are much lighter and thinner than reinforced concrete, yet offer equivalent structural performance. However, they are not widely used in the construction industry. The main reasons are the noise transmission characteristics of steel plates and the flatness problem caused by thermal deformation during welding. Because steel plate structural materials are composed entirely of a high-density single metal, they have superior noise transmission ability compared to other structural materials when subjected to impact. Consequently, they are rarely used as building materials (especially flooring materials where inter-floor noise prevention is crucial). Furthermore, the thermal deformation caused by welding of plate reinforcements makes steel plate structural materials disadvantageous in terms of structural flatness.

[0025] Furthermore, steel plate structural materials are unsuitable for building applications where insulation is crucial due to their excessively high thermal conductivity. While reinforced concrete has a thermal conductivity of 1.6–2.0 W / mK, steel plate has a very high thermal conductivity of 83 W / mK. This high thermal conductivity means that external heat is transferred very quickly and easily to the interior, making it extremely vulnerable to insulation issues.

[0026] The purpose of the present invention is to provide a lightweight structural material based on a high-performance / multi-functional composite material that can be effectively applied to the thin-plate structure of a ship by overcoming the technical limitations described above, and can also be universally applied to other fields such as building structural materials and wall surfaces of pressure vessels.

[0027] More specifically, the present invention aims to dramatically improve the problem of thermal deformation due to conventional welding by drastically reducing the amount of arc welding or gas welding that causes a lot of thermal deformation when assembling plate reinforcement in conventional steel plate structural materials or by replacing the welding process with a bending process.

[0028] In addition, the present invention has as a technical task the provision of a lightweight structural material based on composite materials that can achieve a groundbreaking weight reduction compared to typical heavy industrial structural materials such as conventional steel plate structural materials or reinforced concrete structural materials, and that is not limited to structural materials for ships but can be easily applied to other fields including construction.

[0029] In addition, the present invention provides a lightweight structural material based on composite materials that can be easily utilized as a structural material for various ships by implementing equivalent structural performance without significantly increasing the thickness compared to general steel plate structural materials manufactured from a single metal material, and also by implementing similar shapes and assembly methods, and can be particularly preferably utilized in constructing curved structures such as decks or vertical wall structures of ships, wind deflectors of container ships, and pressure vessels.

[0030] Furthermore, the present invention aims to overcome the drawback of general steel plate structural materials manufactured from a single metal material, which is that it is very difficult to manufacture them into a box-shaped structure, as a major technical challenge. The present invention aims to provide a lightweight structural material based on composite materials, which can be easily manufactured into a box-shaped structure, thereby easily realizing the advantages of such a structure, and which can secure sufficient load-bearing capacity despite its light weight compared to general steel plate structural materials, and thus can be preferably used for wall surfaces of pressure vessels requiring explosion-proof design.

[0031] Furthermore, the present invention seeks to provide a lightweight composite-based structural material that can be manufactured by integrating the functions of longitudinal strength members installed along the longitudinal direction of the structural material. Here, longitudinal strength refers to the strength that resists longitudinal loads that tend to deform the hull in the longitudinal direction, and the longitudinal strength member refers to a member among the components constituting a ship that contributes to longitudinal strength.

[0032] The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0033] According to one aspect of the present invention for achieving the above object, a lightweight structural material based on a composite material can be provided, which includes a first main plate; a second main plate arranged at a predetermined distance from the first main plate; a plurality of reinforcing plates arranged between the first main plate and the second main plate and having one or more bent portions; and a core layer formed in a space between the first main plate and the reinforcing plate, a space between the second main plate and the reinforcing plate, and a space between adjacent reinforcing plates, wherein a plurality of pillar portions formed by adjacent bent portions and the core layer formed therebetween are formed at a predetermined distance to function as a plate reinforcing material.

[0034] The first main plate, the second main plate, and the reinforcing plate may be made of a metal or fiber-reinforced plastic material, and the core layer may be made of a non-metallic material.

[0035] The above core layer can be formed by injecting and curing a liquid, non-foaming polymer solution.

[0036] A lightweight structural material based on a composite material according to one aspect of the present invention may be formed into a plate reinforcement structure including a vertical reinforcement part formed of the column part; and a horizontal reinforcement part formed of the second plate, the reinforcement plate, and a core layer formed therebetween.

[0037] At least some of the above plurality of reinforcing plates may be provided in the form of a tube having a hollow space formed therein.

[0038] The above reinforcing plate may have a polygonal or circular cross-sectional shape.

[0039] A lightweight structural material based on a composite material according to one aspect of the present invention may have a multi-shielding structure made of a composite material of metal and non-metal by the first main plate, the second main plate, the reinforcing plate, and the core layer.

[0040] The above plurality of reinforcing plates can be arranged in at least two rows or at least two layers between the first main plate and the second main plate.

[0041] Insulating material or fireproof material may be inserted and placed in the internal space of the above reinforcing plate.

[0042] At least one of insulation, fireproofing, pipe, and metal reinforcement may be inserted and placed inside the core layer.

[0043] A lightweight structural material based on a composite material according to one aspect of the present invention may further include a finishing member that finishes at least one of the edge portion between the first main plate and the reinforcing plate and the edge portion between the second main plate and the reinforcing plate.

[0044] The above first abacus may be provided as a curved plate having a curvature.

[0045] The above second plate may be provided as a curved plate having a curvature.

[0046] The ends of the first and second main plates may be connected to each other to form a streamlined shape that generates lift.

[0047] According to another aspect of the present invention for achieving the above object, a cell guide structure of a container ship including a lightweight structural material based on a composite material can be provided, the structure including a first main plate made of a metallic material; a second main plate made of a metallic material arranged at a predetermined interval from the first main plate; and a core layer made of a non-metallic material formed between the first main plate and the second main plate, wherein the core layer includes an extension portion that is formed to have a thickness thicker than other portions and protrudes to one side, and the second main plate includes at least two or more bent portions to surround the extension portion.

[0048] The lightweight structural material based on a composite material according to the present invention can be effectively applied to the thin-plate structure of a ship, and can also be universally applied to other fields such as building structural materials and wall surfaces of pressure vessels, and has the following specific effects.

[0049] (1) It is possible to drastically reduce the amount of arc welding or gas welding that causes a lot of thermal deformation in the welding joining process of plate reinforcement required in conventional steel plate structural materials, or to replace the welding process with a bending process, thereby drastically improving the thermal deformation problem caused by conventional welding.

[0050] (2) The lightweight composite-based structural material according to the present invention is significantly lighter than typical heavy industrial structural materials, such as conventional steel plate structural materials or reinforced concrete structural materials, thereby enabling structural weight reduction. Therefore, when used as a structural material for ships or buildings, it has the effect of reducing the overall weight of the structure.

[0051] (3) The lightweight composite-based structural material according to the present invention can be manufactured with a thickness similar to that of a general steel plate structural material made of a single metal material, even though it is based on a composite material, and can also be implemented with a similar shape and assembly method, so it can be easily utilized as a ship structural material. In particular, the lightweight composite-based structural material according to the present invention is expected to have excellent utility when used in the production of decks for personal cargo ships (PCCs), where weight reduction is of paramount importance.

[0052] (4) The lightweight composite-based structural material according to the present invention possesses significant competitiveness, particularly in that it can be easily manufactured in a box-shaped structure. Rather than welding plate reinforcement to a main plate, the lightweight structural material according to the present invention is manufactured by arranging box-shaped reinforcement plates at regular intervals between facing main plates (upper and lower plates) and filling the internal space with polymer, thereby fundamentally resolving conventional manufacturing issues.

[0053] (5) The lightweight structural material based on the composite material according to the present invention has structural strength that increases in proportion to the 2nd to 3rd power of the increase in thickness due to the characteristics of the composite material, and thus, it is lightweight and can realize structural performance superior to that of a general steel plate structural material of similar thickness.

[0054] Accordingly, the lightweight structural material according to the present invention can be preferably used not only for manufacturing structures such as living quarters installed on ships or wind deflectors installed on the bow of container ships to block wind and waves, but is also expected to be usefully applied as a structural material for constructing explosion-proof containers or high-pressure pressure vessels that must withstand strong impact loads.

[0055] (6) The lightweight structural material based on a composite material according to the present invention has the advantage of being able to be used not only in the shipbuilding field but also as a structural material for construction, as it is basically equipped with noise and vibration reduction performance as well as insulation performance, as it is manufactured from a composite material of metal and polymer.

[0056] (7) In particular, the lightweight structural material based on the composite material according to the present invention can realize significantly superior insulation performance. Since the polymer forming the inner core of the lightweight structural material according to the present invention has a thermal conductivity of 0.2 to 0.4 W / mK, it is advantageous in terms of insulation by several dozen times compared to a general steel plate structural material, which has a thermal conductivity of approximately 83 W / mK.

[0057] In addition, the lightweight structural material according to the present invention has a web portion (vertical column portion) of the plate reinforcement that is the most vulnerable in terms of thermal bridge filled with polymer, and a reinforcing plate having a rectangular cross-section and arranged inside the structural material to form a plate reinforcement structure is separated from the upper / lower plates, which are main plates, so that a metal material penetrating the entire structure can be eliminated, and thus a box-shaped structure with significantly superior insulation can be implemented.

[0058] (8) The lightweight composite-based structural material according to the present invention achieves weight reduction by basically replacing the thick steel plates of a general steel plate structure with a lightweight polymer material. Therefore, the amount of steel plate used can be reduced by 40 to 50% or more compared to a general steel plate structure, and thus, it has great competitiveness in terms of cost reduction. Although the unit price of polymer may be higher than that of a general steel structure, the specific gravity of polymer is light, at 1 / 7 to 1 / 10 of that of steel plate, and therefore, the material cost of the polymer used in the lightweight structural material according to the present invention can be lower than the unit price of the steel structure that the polymer replaces.

[0059] In addition, the lightweight structural material based on a composite material according to the present invention implements the performance of the entire structural material by adjusting the thickness of the top plate and reinforcing plate made of a metallic material and the core layer made of a non-metallic material, so the type and thickness of the metal plate can be selected and applied relatively freely, so the design flexibility is very excellent and it has a great advantage in terms of material supply and operation.

[0060] (9) In addition, the lightweight structural material based on a composite material according to the present invention has the advantage of being able to perform bending processing even with equipment of relatively low output when bending a curved body, since it uses a relatively thinner metal plate than a general steel plate structure.

[0061] (10) A lightweight structural material based on a composite material according to one embodiment of the present invention can have the function of a longitudinal strength member simply but effectively by increasing or expanding the length of a part of the configuration.

[0062] (11) Furthermore, the lightweight method of the structure according to the present invention is also very effective in reducing carbon emissions that cause global warming. Embodied carbon emissions, which refer to carbon emissions accompanying the structural manufacturing process, can be generalized as CO2 emissions per ton of each material. In the case of conventional concrete, approximately 1 ton of CO2 is emitted when producing 1 ton, and in the case of steel plates, approximately 2.3 tons of CO2 may be emitted when producing 1 ton. However, by applying the lightweight method of the present invention, CO2 emissions can be suppressed by approximately 30 to 50% compared to general steel structures and approximately 40 to 60% compared to general reinforced concrete.

[0063] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0064] Figure 1 is a drawing showing a conventional ship plate structural material.

[0065] Figure 2 is a drawing showing another example of a conventional ship plate structural material.

[0066] Figure 3 is a drawing to explain why it is difficult to manufacture conventional steel plate structural materials in a box shape.

[0067] Figures 4 to 16 are drawings showing the first to thirteenth embodiments of the lightweight structural material according to the present invention.

[0068] Figure 17 is a drawing showing a stress distribution structure formed at a connection portion between a flat portion and a vertical column portion of a lightweight structural material according to the present invention.

[0069] Figure 18 is a drawing showing a structure in which the insulation performance of a lightweight structural material according to the present invention is reinforced.

[0070] Figure 19 is a drawing showing a structure in which a lightweight structural material according to the present invention is reinforced with a metal material.

[0071] Figure 20 is a drawing for explaining a structure in which a reinforcing plate of a lightweight structural material according to the present invention is additionally divided.

[0072] Figures 21 to 23 are drawings showing the first to third side end finishing and connection structures of the lightweight structural material according to the present invention.

[0073] Figure 24 is a drawing for explaining a manufacturing method of a lightweight structural material according to the present invention.

[0074] Figure 25 is a drawing for explaining an additional method that can be applied in manufacturing a lightweight structural material according to the present invention.

[0075] Figures 26 to 29 are drawings showing the constituent materials required for manufacturing a lightweight structural material according to the present invention.

[0076] Figures 30 to 37 are drawings showing a specific manufacturing method of a lightweight structural material according to the present invention in sequential steps.

[0077] Figure 38 is a drawing showing a transverse connection structure of a lightweight structural material according to the present invention.

[0078] Figure 39 is a drawing showing a longitudinal connection structure of a lightweight structural material according to the present invention.

[0079] Figure 40 is an enlarged view of the portion indicated by 'D' in Figure 39.

[0080] Figure 41 is a drawing showing a connection portion with a hull when using a lightweight structural material according to the present invention as a cofferdam structure of a ship.

[0081] Figure 42 is a drawing showing the lower structure of a lightweight structural material according to the present invention for use as a cofferdam structure.

[0082] Figure 43 is a drawing to explain problems in the manufacturing of a conventional ship's rudder.

[0083] Figure 44 is a drawing showing an example of utilizing a lightweight structural material according to the present invention as a rudder structure of a ship.

[0084] Figure 45 is a drawing showing a cross-section along line AB of the rudder structure illustrated in Figure 44.

[0085] The purpose and technical configuration of the present invention and the resulting operation and effects will be more clearly understood through a detailed description based on the drawings attached to the specification of the present invention.

[0086] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. For example, terms such as "consisting of" or "comprising" used herein should not necessarily be construed to include all of the various components or various steps described in the invention, but rather to mean that some of the components or steps may not be included, or that additional components or steps may be included. Furthermore, the singular forms used herein include plural forms unless the context clearly dictates otherwise.

[0087] Hereinafter, the present invention will be described in detail by describing preferred embodiments thereof with reference to the attached drawings. The embodiments described below are provided to facilitate the technical concept of the present invention for those skilled in the art to understand, and should not be construed as limiting the present invention. It should be understood that the embodiments of the present invention can have various applications to those skilled in the art.

[0088] Ⅰ. Structural characteristics of the lightweight structural material according to the present invention

[0089] The lightweight structural material (100) according to the present invention is basically composed of a composite material of metal and non-metal, including an upper plate (110), a reinforcing plate (120), and a lower plate (130) made of a metal material, and a core layer (140) made of a non-metal material, and is characterized in that a column portion formed by a lower-direction bending portion of the reinforcing plate (120) and a core layer (140) formed along the lower direction between the reinforcing plates (120) functions as a plate reinforcing material.

[0090] The lightweight structural material (100) according to the present invention can have various embodiments depending on the form in which the reinforcing plate (120) is arranged inside and whether or not reinforcement is provided. Hereinafter, preferred and feasible forms of the lightweight structural material (100) according to the present invention will be examined with reference to FIGS. 4 to 14.

[0091] (1) First embodiment (basic structure)

[0092] Referring to FIGS. 4a and 4b, a first embodiment of a lightweight structural material (100) according to the present invention comprises: an upper plate (110) made of a metal material; a lower plate (130) made of a metal material arranged parallel to the upper plate (110) at a position spaced a predetermined distance below the upper plate (110); a plurality of reinforcing plates (120) arranged between the upper plate (110) and the lower plate (130); A structure (circled portion) can be configured to implement the functions of a vertical reinforcement part (Web) and a horizontal reinforcement part (Flange) of a plate reinforcement structure by interlocking the core layer (140) formed between the adjacent reinforcement plates (120) and the lower plate (130), including a non-metallic core layer (140) formed in the space between the upper plate (110) and the reinforcement plate (120), the space between the lower plate (130) and the reinforcement plate (120).

[0093] That is, the lightweight structural material (100) according to the present invention can be formed with a plate reinforcement structure including a vertical reinforcement portion and a horizontal reinforcement portion. Here, the vertical reinforcement portion can include adjacent reinforcement plates (120) and a core layer (140) formed in a space therebetween, and the horizontal reinforcement portion can include a lower plate (130) and a core layer (140) formed in a space between the lower plate (130) and the reinforcement plate (120). The plate reinforcement structure can be located within the space between the upper plate (110) and the lower plate (130).

[0094] The upper plate (110) and the lower plate (130) have a predetermined thickness and may be flat plates or curved plates. For example, the upper plate (110) may be a square plate.

[0095] The lower plate (130) may be shaped in a shape corresponding to the upper plate (110). The ends of the lower plate (130) and the upper plate (110) may be arranged so that they are aligned vertically (i.e., overlap when viewed from above).

[0096] The reinforcing plate (120) is placed at a predetermined interval so that a space can be formed between it and the upper plate (110), and can also be placed at a similar interval from the lower plate (130).

[0097] The reinforcing plate (120) may be manufactured separately into a plurality of components, and may include a structure that is bent downward from the upper plate (110) so as to perform the function of a plate reinforcing member. Specifically, in FIG. 4a, the reinforcing plate (120) may include a first reinforcing plate (120c) having a cross-section in the shape of the letter 'ㄷ', and a second reinforcing plate (120d) having a tubular shape with a space formed therein. In the attached drawing, the second reinforcing plate (120d) is illustrated as having a cross-section in the shape of the letter 'ㅁ', but the second reinforcing plate (120d) may also be provided in the shape of a tube with a polygonal or circular cross-section.

[0098] First reinforcing plates (120c) are arranged at both ends along the width direction of the lightweight structural material (100), and at least one second reinforcing plate (120d) can be repeatedly arranged between them. The gaps between the first reinforcing plate (120c) and the second reinforcing plate (120d) and between adjacent second reinforcing plates (120d) can be formed to be the same. The reinforcing plate (120) can be bent to have a cross-section in the shape of the letter 'ㄷ' or 'ㅁ' through bending.

[0099] A similar method is repeated in Fig. 4b. The reinforcing plate (120) may include a fourth reinforcing plate (120e) having an overall 'ㄱ'-shaped cross-section, a second reinforcing plate (120d) having an 'ㅁ'-shaped cross-section, and a sixth reinforcing plate (120f) having a laid-down 'ㄷ'-shaped cross-section. The second reinforcing plate (120d) is in the shape of a tube with a space formed inside, and its cross-section may be polygonal or circular.

[0100] The fourth reinforcing plate (120e) and the lower plate (130) and / or the sixth reinforcing plate (120f) and the lower plate (130) can be bent as an integral part or processed separately and then joined through welding (preferably, laser welding).

[0101] The core layer (140) may be formed in the space between the upper plate (110) and the reinforcing plate (120) and the lower plate (130), and in the space between the adjacent reinforcing plates (120). The core layer (140) may be formed of a non-foaming polymer. More preferably, the core layer (140) is a material having suitable elasticity and structural strength, and having a density of 700 kg / m. 3 The ideal compressive strength is 3 N / mm 2 It can be formed of an ideal non-foaming polyurethane. As described below, the non-foaming polymer solution filled in the space can be cured to form a core layer (140).

[0102] The lightweight structural material (100) according to the present invention has an upper flat plate formed in a horizontal direction by an upper plate (110), a reinforcing plate (120), and a core layer (140) filled therebetween, and a lower flat plate formed in a horizontal direction by a lower plate (130), a reinforcing plate (120), and a core layer (140) filled therebetween, which serve as structural members that bear a load.

[0103] In addition, a vertical column section composed of a reinforcing plate (120) facing each other at a predetermined interval and a core layer (140) therebetween is repeatedly formed at a predetermined interval, thereby functioning as a plate reinforcing material that enhances the structural performance of the flat plate section and prevents buckling.

[0104] Accordingly, the lightweight structural material (100) according to the present invention can implement a 'box-shaped structure' in which a plurality of plate reinforcing structures (vertical pillars) are repeatedly formed between the upper plate (110) and the lower plate (130), which are the main plates (Fig. 4a).

[0105] At this time, the present invention is not a structure in which the upper plate (110), the lower plate (130), and the reinforcing plate (120) for forming the plate reinforcing structure are joined to each other by welding, but is manufactured by filling the internal space with polymer while being arranged at intervals from each other, so it has the advantage of being able to easily implement a box-shaped structure without the conventional manufacturing problems (described with reference to FIG. 3).

[0106] In addition, the lightweight structural material (100) according to the present invention has a continuous form in which the flat portion formed in the horizontal direction and the vertical column portion formed in the vertical direction are not separated, so it is possible to implement a structure that is strong and free from concerns about thermal deformation or cracks due to welding.

[0107] The lightweight structural material (100) according to the present invention having such a strong structure may have a reinforcing plate (120) disposed in the middle made of a metal material, such as an upper plate (110) or a lower plate (130), but sufficient structural strength may be achieved even if it is made of a composite material such as fiber reinforced plastic (FRP).

[0108] (2) Second and third embodiments (multi-stage deck structure)

[0109] The lightweight structural material (100) according to the present invention has another advantage in that it can easily implement a multi-stage deck structure.

[0110] For example, referring to FIGS. 5 and 6, a second reinforcing plate (120d) having a hexahedral space formed therein can be arranged inside the core layer (140) to form multiple rows and layers, thereby implementing a multi-stage deck structure.

[0111] At this time, as illustrated in FIGS. 5b and 6b, the cross-section of the first reinforcing plate (120c) arranged at both ends of the lightweight structural material (100) may be configured to be a simple straight line rather than a 'ㄷ' shape to connect the upper plate (110) and the lower plate (130), and such a structure may be used as a container for transporting heavy objects having a multi-stage deck. That is, the internal space of a plurality of second reinforcing plates (120c) arranged inside the core layer (140) may be used as a storage space for transporting heavy objects.

[0112] Conventional construction of multi-deck containers, rack structures, and the like requires welding each deck to the existing skeletal structure. Each deck must be sufficiently strong and thick to safely store heavy loads. For example, the decks of multi-deck containers are constructed by welding thick angles or channels to the skeletal structure, then bonding them with thick plywood or other materials to maintain structural rigidity.

[0113] However, the problem is that as the deck-to-deck height decreases, the work becomes significantly more difficult, or even impossible. When the deck-to-deck height is less than 1,600 mm (approximately 6.5 inches), which is typically too low for a person to stand, the worker must bend over to perform the work, which takes at least twice as long as standing. If the deck-to-deck height is less than 400 to 600 mm (approximately 1,600 inches), even lying down becomes difficult, making welding and rigid structural fastening nearly impossible.

[0114] Furthermore, typical multi-level deck structures have gaps between angles or channels, making the plywood placed between them structurally vulnerable, resulting in poor durability. Furthermore, because the angles or channels and the deck floor are separated, microscopic gaps can form, allowing water to pass through, posing a waterproofing issue. This makes them unsuitable for use as containers transporting hazardous or moisture-sensitive cargo.

[0115] However, by using the box-type method of the present invention, it is possible to easily implement a multi-stage deck structure for transporting heavy objects, which was very cumbersome or impossible to manufacture using the existing method as described above.

[0116] Specifically, a box-shaped structure may be prefabricated with an upper plate (110), a lower plate (130), and a reinforcing plate (120), and the positions of the upper plate (110), the lower plate (130), and the reinforcing plate (120) are fixed using a work jig or the like, and then a liquid polymer solution is injected into a space formed within the box-shaped structure. A multi-stage deck structure may be formed by arranging a plurality of reinforcing plates (120) adjacent to each other in the horizontal and vertical directions.

[0117] According to the method of the present invention as described above, the injected polymer solution can easily fill the empty space, and since welding work in a narrow space, etc. is not required as in the past, a multi-stage deck structure can be conveniently manufactured.

[0118] When the lightweight structural material (100) according to the present invention is used as a multi-deck container, the height of the second reinforcing plate (120d) placed inside can be adjusted as desired, so it has the advantage of ultimately being able to implement the height between decks as desired.

[0119] In addition, unlike the conventional method where the deck is laid on angles or channels, the entire structure including the walls and deck is composed of a uniform composite structure made of polymer and metal plates, so there is no structurally weak area.

[0120] In addition, the multi-deck container using the lightweight structural material (100) according to the present invention has a continuous shape without separation between the wall and the deck, so perfect watertightness / airtightness can be achieved between the decks.

[0121] Meanwhile, in the process of manufacturing the lightweight structural material (100) according to the present invention into a multi-stage deck-type container, various fillers can be pre-inserted into the space where the core layer (140) is to be formed before the polymer is injected, thereby easily adding desired functions. For example, fire-resistant materials for fire resistance or insulation materials for insulation can be additionally placed in the space, or hot / cold pipes or hydraulic lines can be pre-installed.

[0122] A multi-deck container using a lightweight structural material (100) according to the present invention has a multi-composite structure including a metal-polymer-metal bulkhead between decks, and the polymer has a thermal conductivity of approximately 0.2 to 0.4 W / mK, which is hundreds of times higher in heat transfer blocking performance than metal, and thus has a performance far superior to a multi-deck structure using a general single metal material in terms of insulation.

[0123] (3) Fourth and fifth embodiments

[0124] The fourth and fifth embodiments of the lightweight structural material (100) according to the present invention, illustrated in FIGS. 7 and 8, differ from the first embodiment illustrated in FIG. 4 in that the cross-sectional shape of the space formed by the reinforcing plate (120) is polygonal or circular rather than rectangular. Descriptions of the same configuration as the first embodiment are omitted.

[0125] As shown in Fig. 7, when the cross-sectional shape of the space formed by the reinforcing plate (120) is triangular, the specific gravity of the metal structure increases, which has the advantage of being resistant to compressive load or buckling.

[0126] When the cross-sectional shape of the space formed by the reinforcing plate (120) is formed as a trapezoid as shown in Fig. 8, it may be advantageous in terms of compressive load or buckling compared to the case where the cross-section is rectangular as shown in Fig. 4.

[0127] The lightweight structural material (100) of the present invention may have a cross-sectional shape of various shapes, such as a circle, in addition to the triangular and trapezoidal shapes shown in FIGS. 7 and 8.

[0128] (4) 6th embodiment

[0129] The sixth embodiment of the lightweight structural material (100) according to the present invention illustrated in FIG. 9 differs from the first embodiment illustrated in FIG. 4 in that it includes an extension portion (330) that is formed longer than the other vertical pillar portions. Descriptions of the same configuration as the first embodiment are omitted.

[0130] The reinforcing plate (120) of the lightweight structural material (100) of the present embodiment includes a third reinforcing plate (120h). The third reinforcing plate (120h) has a cross-section in the shape of the letter 'ㅁ', similar to the second reinforcing plate (120d), but is formed to be longer in the vertical direction than the second reinforcing plate (120d).

[0131] The lower plate (130) of the lightweight structural material (100) of this embodiment is bent downward at the portion where the third reinforcing plate (120h) is placed.

[0132] The lightweight structural material (100) of this embodiment can have the function of a longitudinal strength member by itself by including an extension part (330).

[0133] (5) Seventh embodiment

[0134] The seventh embodiment of the lightweight structural material (100) according to the present invention illustrated in FIG. 10 differs from the sixth embodiment illustrated in FIG. 9 in that it further includes one or more additional reinforcing plates (170). Descriptions of the same configuration as the sixth embodiment are omitted.

[0135] When the lightweight structural material (100) of the present invention is configured to include the function of a longitudinal strength member, the load may be concentrated on the extension portion (330), and buckling or damage may occur in the extension portion (330) due to shear force, etc. Therefore, in the present embodiment, the extension portion (330) may be designed to have higher strength than other vertical column portions in order to prevent buckling and damage of the extension portion (330).

[0136] In order to increase the strength of the extension (330), the thickness of the extension (330) may be formed thicker, but if only the thickness of the extension (330) is formed thicker, the process becomes complicated and inefficient, and if the entire reinforcing plate (120) is formed thicker, the parts other than the extension may be overdesigned, which may increase the overall weight and increase the manufacturing cost.

[0137] The lightweight structural material (100) of the present embodiment can increase the strength of the extension portion (330) by arranging one or more additional reinforcing plates (170) inside the core layer (140). When the polymer solution is injected and cured while the additional reinforcing plates (170) are placed in place, the additional reinforcing plates (170) can be integrated into the core layer (140). It is preferable that the additional reinforcing plates (170) are vertically arranged inside the core layer (140) formed in the extension portion (330), and two additional reinforcing plates (170) can be arranged on each side.

[0138] (6) Eighth embodiment

[0139] The eighth embodiment of the lightweight structural material (100) according to the present invention illustrated in FIG. 11 differs from the sixth embodiment illustrated in FIG. 9 in that the extension portion (330) includes a plurality of reinforcing plates (120). Descriptions of the same configuration as the sixth embodiment are omitted.

[0140] For example, as illustrated in FIG. 11, the extension (330) of the present embodiment may include two reinforcing plates (120i, 120j) arranged vertically. The present invention is not limited thereto, and the extension (330) may be configured to include more reinforcing plates (120) as needed.

[0141] (7) 9th embodiment

[0142] The ninth embodiment of the lightweight structural material (100) according to the present invention illustrated in FIG. 12 differs from the sixth embodiment illustrated in FIG. 9 in that the extension portion (330) does not include a reinforcing plate (120). Descriptions of the same configuration as the sixth embodiment are omitted.

[0143] The extension (330) of this embodiment does not have a reinforcing plate (120) placed inside, and the inside is made up of only a core layer (140).

[0144] As illustrated in FIGS. 12b and 12c, the extension (330) of the present embodiment may further include reinforcing members (157, 158) to enhance strength. It is preferable that the reinforcing members (157, 158) be made of a material (e.g., a metal material) that is harder than the core layer (140).

[0145] The reinforcing member (157, 158) may be placed at the lower end of the extension (330) as shown in FIG. 12b, or may be placed vertically in the center of the extension (330) with a cross-section formed in an 'I' shape as shown in FIG. 12c.

[0146] (8) 10th embodiment

[0147] The tenth embodiment of the lightweight structural material (100) according to the present invention illustrated in FIG. 13 has a difference from the ninth embodiment illustrated in FIG. 12 in that the lower end of the extension portion (330) is formed to have a cross-section in the shape of the letter '┘'. Descriptions of the same configuration as the ninth embodiment are omitted.

[0148] As illustrated in FIG. 13b, a reinforcing member (154) having a cross-section in the shape of the letter '┘' may be placed at the bottom of the extension portion (330) of the present embodiment to match the shape of the bottom of the extension portion (330).

[0149] (9) 11th embodiment

[0150] The 11th embodiment of the lightweight structural material (100) according to the present invention illustrated in FIG. 14 has a difference from the 9th embodiment illustrated in FIG. 12 in that the lower end of the extension portion (330) is formed to have a cross-section in the shape of the letter '┴'. Descriptions of the same configuration as the 9th embodiment are omitted.

[0151] As illustrated in Fig. 14b, a reinforcing member (155) having a cross-section in the shape of the letter '┴' may be placed at the bottom of the extension portion (330) of the present embodiment to match the shape of the bottom of the extension portion (330).

[0152] (10) 12th embodiment

[0153] The twelfth embodiment of the lightweight structural material (100) according to the present invention illustrated in FIG. 15 is characterized by including one or more pipes (180). FIG. 15a illustrates a case where the length of the vertical column portion is constant as illustrated in FIG. 4, and FIGS. 15b to 15d illustrate a case where an extension portion (330) is included as illustrated in FIG. 9. Although not illustrated separately, the pipe (180) may also be applied to other embodiments, such as a case where the extension portion (330) includes a plurality of reinforcing plates (120) (FIG. 11), a case where the extension portion (330) does not include a reinforcing plate (120) (FIG. 12), a case where the lower shape of the extension portion (330) is configured in a '┘' shape (FIG. 13), or a case where the extension portion (330) is configured in a '┴' shape (FIG. 14).

[0154] The pipe (180) is arranged on the 'upper flat plate' formed horizontally on the lower side of the upper plate (110), and a plurality of pipes (180) can be arranged in parallel along the upper flat plate. The plurality of pipes (180) can be arranged at regular intervals, or there can be sections arranged at different intervals as needed.

[0155] The pipe (180) may be arranged closer to the upper plate (110) as shown in FIG. 15a, or may be arranged at approximately the midpoint between the upper plate (110) and the reinforcing plate (120) as shown in FIG. 15b. Alternatively, multiple pipes (180) may be arranged vertically as shown in FIG. 15c. In FIG. 15c, two rows of pipes (180) are illustrated as being arranged vertically, but three or more rows may be arranged as needed, and the pipes may be arranged not horizontally or vertically but offset from each other.

[0156] The pipe (180) can be placed inside the core layer (140). After the pipe (180) is placed between the top plate (110) and the reinforcing plate (120), the original solution for forming the core layer (140) is filled and hardened, thereby forming a high-density sealed structure around the pipe (180). In this case, even if a crack occurs in the pipe (180), since the exterior of the pipe (180) is sealed by the high-density structure, leakage from the pipe (180) does not occur and the overall structure of the lightweight structural material (100) is not affected.

[0157] The pipe (180) can perform cooling and heating functions. To enable rapid heat circulation, the pipe (180) is preferably made of a metal material, but the present invention is not limited thereto.

[0158] Referring to FIG. 15d, the lightweight structural material (100) of the present embodiment may further include a pipe installation member (185). The pipe installation member (185) is intended to facilitate the installation of the pipe (180), and the pipe installation member (185) may be installed first, and then the pipe (180) may be installed thereon.

[0159] The pipe installation member (185) is preferably a structure that can withstand the weight of the pipe (180) while not significantly increasing the weight of the lightweight structural member (100) of the present invention. For example, it may be a thin mesh structure. In addition, fixed pins, spacers, etc. may be used.

[0160] Buildings and ships often require cooling and heating facilities, and data centers in particular generate significant heat. Failure to properly remove this heat can lead to high indoor temperatures, which can degrade the performance of data storage devices and other equipment.

[0161] Looking at existing pipe installation work, it is difficult to install pipes during concrete structural construction, and pipe installation work (usually called 'proofing work') is usually done after the concrete structural construction is completed. Since high-pressure and heavy ready-mixed concrete is applied during concrete pouring, if ready-mixed concrete is applied after the pipes are installed in advance, there is a high possibility of pipe damage and / or displacement of the pipes. In addition, even if the pipes are properly installed, if cracks occur in the pipes later, the fluid inside the pipes can seep into the concrete structure, reducing the structural performance and even leading to collapse.

[0162] Pipe installation work (proofing work) is carried out by installing pipes on a concrete structure and then constructing mortar, etc. on top of them. This type of pipe installation work is generally carried out on the floor, and carrying out the proofing work on the ceiling or wall is very cumbersome in terms of construction method.

[0163] However, according to the lightweight structural material (100) of the present embodiment, since separate pipe installation work is not required simply by placing the lightweight structural material (100), work efficiency is improved. When the lightweight structural material (100) of the present embodiment is used as a floor structure, floor cooling and heating (Ondol type) are possible by means of pipes (180). In addition, the lightweight structural material (100) of the present embodiment can be applied not only to floor structures but also to wall and ceiling structures, and in this case, pipe installation is possible easily on the wall and ceiling. In addition, when the lightweight structural material (100) of the present embodiment is applied to each of multiple floor structures, the heat sources of the ceiling of the lower floor and the floor of the upper floor can be controlled simultaneously by the pipes (180).

[0164] (11) 13th embodiment

[0165] The 13th embodiment of the lightweight structural material (100) according to the present invention illustrated in FIG. 16 is characterized by further including a border bar (175) and a protruding member (177).

[0166] A border bar (175) may be installed between the upper plate (110) and the reinforcing plate (120) of the lightweight structural material (100) and between the lower plate (130) and the reinforcing plate (120) to assist in joining by means of bolting or welding. At this time, as illustrated in Fig. 16a, there is a problem that the border bar (175) may be separated due to a load applied to the lightweight structural material (100).

[0167] To prevent such problems, referring to FIGS. 16b and 16c, one or more protruding members (177) may be installed on the inner surface of the edge bar (175). When the edge bar (175) with the protruding members (177) installed is placed in position and the polymer solution is injected and cured, the protruding members (177) may form a wedge structure embedded in the core layer (140), thereby preventing the edge bar (175) from being separated.

[0168] (12) Additional supplementary examples

[0169] A. Stress distribution structure

[0170] The lightweight structural material (100) according to the present invention can additionally easily implement a structure to alleviate the concentration of stress in the bending portion extending from the flat portion to the vertical column portion.

[0171] The conventional steel plate structural material illustrated in Fig. 2 inevitably has a structure that is sharply bent at a 90° angle at the point where the upper plate (10), lower plate (30), and plate reinforcement (20) are welded. In addition to the concentration of stress in the relevant area, this structure also has the disadvantage of easily peeling off the coating intended to prevent corrosion.

[0172] In order to improve these problems, as shown in Fig. 17a, a method of adding a triangular metal reinforcement (21) to the area where the upper plate (10) and lower plate (30) and the plate reinforcement (20) meet in a conventional steel plate structural member can be considered, but not only is welding of the triangular metal reinforcement (21) itself not easy, but a part that is structurally weak in welding is created, and there is also a disadvantage in that the overall weight of the structural member greatly increases, so there are few cases in which it is applied.

[0173] However, since the lightweight structural material (100) proposed in the present invention does not have a structure in which the flat plate portion and the vertical column portion that serves as the plate reinforcement portion are separated from each other, it is very easy to implement a gentle slope at the connection portion between the flat plate portion and the vertical column portion by a method such as additionally bending the reinforcement plate (120) as illustrated in Fig. 17b. That is, the four corner portions of the reinforcement plate (120) having a cross-section in the shape of a 'ㅁ' can be manufactured with a chamfer structure that is inclined diagonally.

[0174] In addition, although not shown in the drawing, it is also possible to configure the connecting portion between the flat portion and the vertical column portion in a round shape. Since the lightweight structural member (100) according to the present invention has a reinforcing plate (120) made of a thin plate, it is not difficult to implement the connecting portion in a round shape.

[0175] In addition, since the specific gravity of the inner core layer (140) of the lightweight structural material (100) according to the present invention is only 1 / 7 to 1 / 8 of that of the metal, the increase in weight is also minimal. Therefore, the phenomenon of stress being concentrated at the connection between the flat portion and the vertical column portion of the lightweight structural material (100) according to the present invention can be effectively alleviated, and the durability and service life of the coating can be significantly increased.

[0176] B. Reinforcement of insulation performance

[0177] A structure for reinforcing the insulation performance of a lightweight structural material (100) according to the present invention is presented as follows.

[0178] First, as illustrated in Fig. 18a, when forming the core layer (140) of the lightweight structural material (100), a high-performance insulating material with already implemented structural performance can be additionally utilized. That is, a high-performance insulating material (141) with low thermal conductivity can be additionally placed between the upper plate (110) and the reinforcing plate (120) and / or between the lower plate (130) and the reinforcing plate (120), and in this case, superior performance in terms of insulation and structure can be achieved.

[0179] More specifically, a high-performance insulating material (141) having a thermal conductivity of lower than 0.02 W / mK may be placed between the upper plate (110) and the reinforcing plate (120) and / or between the lower plate (130) and the reinforcing plate (120) together with a non-foaming polymer to form a core layer (140). For example, when the core layer (140) is formed to include a vacuum insulation material (VIP: Vacuum Insulation Panel) having a thermal conductivity of 0.004 W / mK, the overall thickness of the lightweight structural material (100) may increase somewhat, but in terms of insulation properties, it is possible to implement insulation performance that is 6 to 10 times better than that of a general EPS (Expanded Polystyrene) insulation. In addition, since the structural strength increases in proportion to the 2 to 3 power of the thickness increase due to the characteristics of the composite material, it is possible to implement lightweight but superior structural performance.

[0180] In addition, when the vacuum insulation material is included within a non-foaming polymer, the vacuum insulation material can be more effectively protected from external impact, and the gas inflow into the vacuum insulation material is completely blocked by the airtight structure of the non-foaming polymer, so that the lifespan of the vacuum insulation material can be extended almost permanently.

[0181] When the core layer (140) is composed only of a non-foaming polymer, there is an advantage in that the thickness of the lightweight structural material (100) can be optimized and manufactured to a very thin thickness. On the other hand, when a high-performance insulating material (141) such as a vacuum insulating material is additionally included together with the non-foaming polymer, there is an advantage in that the lightweight structural material (100) is simpler in terms of manufacturing (since the non-foaming polymer solution can be applied to the surface of the high-performance insulating material (141) and used as an adhesive) and excellent insulating performance can be obtained. Therefore, when forming the core layer (140) of the lightweight structural material (100) according to the present invention, it is possible to select and apply whether to use the non-foaming polymer alone or to use it together with the high-performance insulating material (141) by taking into account the advantages of each method.

[0182] For reference, if the core layer (140) is composed of only high-performance insulating material (141), the bonding strength with the top plate (110) and the reinforcing plate (120) is weak, making it difficult to secure sufficient structural performance. In order for the lightweight structural material (100) of the present invention to obtain satisfactory structural performance, the non-foaming polymer surrounding the high-performance insulating material (141) must maintain a form in which it is firmly fixed by adhesion between the top plate (110) and the reinforcing plate (120).

[0183] Meanwhile, referring to FIG. 18b, the lightweight structural material (100) according to the present invention, which takes on a box-shaped structure, can easily increase the insulation performance of the entire structure simply by inserting and placing a general insulation material (I), such as polyurethane foam or civil engineering EPS, into the box space formed inside. In addition, it may be possible to additionally implement fire resistance performance by placing a fire-resistant material within the box space.

[0184] Since the insulation material (I) inserted into the internal space of the reinforcing plate (120) is shielded and protected by the strong composite structure of the lightweight structural material (100), there is no need to perform separate finishing work to protect the insulation material, and the effect of increasing the durability of the insulation material (I) can also be expected.

[0185] The above structure is expected to be very useful when used in the production of ship storage tanks, etc., where insulation is essential.

[0186] C. Additional placement of metal reinforcement

[0187] Meanwhile, the lightweight structural material (100) according to the present invention is configured such that the upper plate (110), lower plate (130), and reinforcing plate (120) forming the outer plate are made of metal plates having a thickness much thinner than that used in conventional steel plate structural materials with equivalent performance. Therefore, when additional members (e.g., longitudinal / transverse girders, etc.) need to be welded to the outer plate of the lightweight structural material (100) according to the present invention, a problem of the inner core burning due to the welding heat may occur. To prevent this problem, a metal material may be reinforced and placed in the area where the additional members are welded before injecting the polymer to form the core layer (140).

[0188] Additionally, metal materials may be placed in any area for the purpose of local reinforcement of the upper plate (110), lower plate (130), or reinforcing plate (120) of the lightweight structural material (100).

[0189] For example, referring to FIG. 19, the metal reinforcement (142) can be freely placed at a location requiring reinforcement in the space between the upper plate (110) or the lower plate (130) and the reinforcement plate (120). Although not shown, the metal reinforcement (142) can be placed anywhere requiring reinforcement, such as a space between vertically positioned reinforcement plates (120) facing each other, or an outer surface of the upper plate (110), the lower plate (130), or the reinforcement plate (120). When the metal reinforcement (142) is placed in the middle of the core layer (140), it can be placed with a thickness corresponding to the entire core layer (140), but is not necessarily limited thereto, and can be placed in a form added to one side of the upper plate (110), the lower plate (130), or the reinforcement plate (120) at a location requiring reinforcement.

[0190] The lightweight structural material (100) according to the present invention is capable of structurally integrated behavior because the polymer forming the inner core firmly attaches all components. Therefore, even without using a high-strength bonding method such as welding, the metal reinforcing material (142) is firmly fixed within the core layer (140) through interaction with the polymer, enabling stable behavior.

[0191] D. Additional division of reinforcement plate

[0192] As described above, in order to implement the plate reinforcement integral lightweight structural material (100) proposed by the present invention, the reinforcement plate (120) is bent at least once or several times and used in various shapes.

[0193] Meanwhile, for ship structural materials, it is advantageous to be sufficiently long to increase manufacturability within a shipyard, and structural materials of approximately 5 to 10 meters are commonly used. The reinforcing plate (120) constituting the lightweight structural material (100) according to the present invention has the advantage of being easily shaped through bending; however, due to limitations in the performance of bending equipment, a method of splitting the reinforcing plate (120) into multiple pieces and joining them together may be required.

[0194] In addition, as mentioned above, the reinforcing plates (120) of the lightweight structural member (100) constituting one unit can be manufactured separately in multiple pieces. In this case, the gap between adjacent reinforcing plates (120) may be reduced or increased due to manufacturing / installation errors. If 4 to 10 reinforcing plates (120) are sequentially arranged on one lightweight structural member (100), the manufacturing / installation errors as described above may accumulate, which may result in defective products in which the steps at the ends of the lightweight structural member (100) do not match or in which the vertical column portions that perform the web function of the plate reinforcing member have uneven thicknesses. In particular, since the lightweight structural member (100) proposed in the present invention has a core (polymer) thickness of about 4 to 5 mm thinly formed, even if an error of only about 1 to 2 mm occurs, it may have a significant impact on the overall structural performance.

[0195] In addition, since the load stress requirements for each element of the reinforcing plate (120) constituting the vertical column of the lightweight structural material (100) are different, there may be cases where metal plates of different thicknesses must be used.

[0196] For this reason, the reinforcing plate (120) constituting the lightweight structural material (100) of the present invention can be manufactured by dividing it into smaller units and joining them through welding. For example, in order to implement the box-shaped plate reinforcing material-integrated lightweight structural material (100) proposed by the present invention, a reinforcing plate (120) having a cross-section in the shape of the letter 'ㅁ' as illustrated in FIG. 20 can be used. In this case, as illustrated in the lower part of the drawing, the reinforcing plate (120) can be additionally divided into two units, manufactured, and then joined through welding.

[0197] Ⅱ. Advantages and structural dimensions of the lightweight structural material according to the present invention

[0198] In the lightweight structural material (100) according to the present invention described above, the vertical column portion formed in the vertical direction, i.e., the portion formed in the shape of a vertical column by the facing reinforcing plates (120) and the core layer (140) formed therebetween, functions to increase the cross-sectional modulus of the entire structure. The cross-sectional modulus can be determined by the height or shape of the vertical column portion functioning as a plate reinforcing structure.

[0199] Conventional steel plate structural materials composed only of metal, which are mainly applied to ship structures (see FIGS. 1 and 2), are connected by welding a plate reinforcing material (20) to the lower side of the upper plate (10) or between the upper plate (10) and the lower plate (30) for structural reinforcement. As explained in the background art, this conventional method has a problem in that significant thermal deformation occurs when the plate reinforcing material (20) is connected by welding.

[0200] However, unlike conventional steel plate structural materials in which the upper plate (10) and lower plate (30) functioning as structural members and the plate reinforcement (20) are manufactured separately and then joined by welding, the lightweight structural material (100) according to the present invention is manufactured in a form in which the flat plate portion and the vertical column portion are manufactured as an integral part and the plate reinforcement structure is already included within itself, so there is no concern at all about the occurrence of thermal deformation problems due to welding as in the conventional case.

[0201] In addition, even if we assume a case where the plate reinforcement (20) is bolted instead of welded when manufacturing a conventional steel plate structural material, additional hole construction or local structural reinforcement work is required for bolting connection between the upper plate (10) or lower plate (130) and the plate reinforcement (20). In contrast, the lightweight structural material (100) according to the present invention in which the plate reinforcement structure is formed integrally does not require any of the above-mentioned additional processes, and thus can have structurally stable performance.

[0202] In addition, since the lightweight structural material (100) according to the present invention is in a form in which a plate reinforcement structure by a vertical column portion is already included in itself, it is possible to manufacture an optimized composite structure by forming the upper plate (110) and lower plate (130) and the reinforcement plate (120) into a much thinner structure compared to a case in which welding of the plate reinforcement structure is required.

[0203] In particular, the lightweight structural material (100) according to the present invention is characterized in that not only the flat portion but also the vertical column portion that functions as a plate reinforcement is composed of a composite material (metal + polymer) rather than a single metal material. According to this structure of the present invention, there is an advantage in that a structural weight reduction of approximately 40 to 50% can be achieved compared to the case where a plate reinforcement composed solely of metal is used.

[0204] The thickness of the upper plate (110), the lower plate (130), the reinforcing plate (120) constituting the outer plate of the lightweight structural material (100) according to the present invention, and the core layer (140) constituting the inner core can be designed to such an extent that the lightweight structural material (100) according to the present invention can implement structural performance equivalent to the structural strength of a general steel plate structural material.

[0205] Specifically, the thickness of the upper plate (110), the lower plate (130), and the reinforcing plate (120) of the lightweight structural material (100) according to the present invention may be formed to be 0.4 to 20 mm, respectively. At this time, as described later, when the lightweight structural material (100) according to the present invention is to be connected to individual modules or to another structure, there are cases where welding work must be performed. Therefore, the thickness of the upper plate (110), the lower plate (130), and the reinforcing plate (120) constituting the outer plate is preferably formed to be 0.4 mm or more, which facilitates laser welding. In addition, in order to achieve structural weight reduction of the lightweight structural material (100) according to the present invention, it is preferable that the thickness of the upper plate (110), the lower plate (130), and the reinforcing plate (120) be formed to be 10 mm or less, and therefore, the present invention suggests 0.4 to 10 mm as a more preferable thickness of the metal plates constituting the upper plate (110), the lower plate (130), and the reinforcing plate (120).

[0206] The thickness of the core layer (140) of the lightweight structural material (100) according to the present invention can be configured to vary from 3 to 40 mm. In this case, the core layer (140) may be formed with different thicknesses in the portion formed in the horizontal direction and the portion formed in the vertical direction.

[0207] That is, in the lightweight structural material (100) according to the present invention, the core layer (140) thickness in the flat portion and the core layer (140) thickness in the vertical column portion may be formed to be the same, but the thicknesses may also be adjusted to be different. In the case where it is desired to form the thicknesses to be different, it is preferable that the core layer (140) thickness in the vertical column portion, which functions as a plate reinforcement, be formed to be thinner than the core layer (140) thickness in the flat portion.

[0208] Meanwhile, there is something that should not be confused by the names of the parts mentioned above. For example, it should be understood that the upper plate (110) of the lightweight structural material (100) according to the present invention does not have to have structural performance equivalent to that of the upper plate (10) of a general steel plate structural material alone, but that the upper flat plate portion of the lightweight structural material (100) according to the present invention, including the upper plate (110), the reinforcing plate (120), and the core layer (140) formed therebetween, formed in a horizontal direction and directly in contact with the design load, can be designed to have structural performance equivalent to that of the upper plate (10) of the general steel plate structural material. This also applies to determining the thickness of the reinforcing plate (120) constituting the plate reinforcing structure and the core layer (140) formed therebetween.

[0209] That is, in the lightweight structural material (100) according to the present invention, the entire upper flat plate including the top plate (110), the reinforcing plate (120), and the core layer (140) formed therebetween must be considered in order to correspond to the top plate (10) of a general steel plate structural material in terms of structural strength, and therefore, in the lightweight structural material (100) according to the present invention, which is designed to have structural performance equivalent to that of a general steel plate structural material, the thickness of the top plate (110) will be much thinner than the top plate (10) of the corresponding general steel plate structural material. For example, the lightweight structural material (100) according to the present invention, which is equivalent to a 6 mm thick top plate (10) of a general steel plate structural material, can be formed as a composite structure with a 1 mm thick top plate (110), a 5 mm thick core layer (140), and a 1 mm thick reinforcing plate (120).

[0210] In addition, the spacing between the vertical columns that perform the web function of the plate reinforcement in the lightweight structural material (100) according to the present invention can be formed within the range of 200 to 3,000 mm. More preferably, the spacing between the vertical columns of the lightweight structural material (100) according to the present invention can be formed to be approximately 600 to 900 mm, which is similar to the spacing of a general steel plate structural material, and if the thin thickness of the lightweight structural material (100) is sacrificed (for example, if the thickness is increased by arranging a high-performance insulation material (141) inside the core layer (140) as described below), the spacing between the vertical columns can be increased to 1,500 to 3,000 mm. Here, the spacing between the vertical columns can be determined by the horizontal length of the reinforcement plate (120).

[0211] The width of the lightweight structural material (100) according to the present invention can be varied depending on the number of vertical pillars formed. For example, when the spacing between vertical pillars is uniformly 700 mm, if the structure has 3 to 5 vertical pillars, the width of the entire plate can be formed to be approximately 2,100 to 3,500 mm.

[0212] The height of the vertical column formed in the vertical direction in the lightweight structural material (100) can be formed at a level that has structural performance equivalent to that of a general steel plate structural material by comparing the section modulus of the entire structure, and can be manufactured to be similar to or lower than that of an existing plate reinforcement material made only of metal. For example, if the height of the plate reinforcement material of an existing steel plate structural material to implement equivalent performance is 100 mm, the height of the vertical column of the lightweight structural material (100) according to the present invention can also be formed at a similar level. Here, the height of the vertical column can mean the entire height of the reinforcement plate (120).

[0213] For reference, in order to achieve structural performance equivalent to that of a general steel plate structural material by simply filling a non-foaming polymer between a flat upper plate and a lower plate without utilizing the structural features of the plate-reinforced integrated lightweight structural material (100) proposed by the present invention, a very thick and heavy structure would be required.

[0214] For example, if a hull structure that can withstand a load of about 20 tons with a width of 3.2 m is required, if a general steel plate structural material (see Fig. 1) is used, a plate reinforcement material (20) that is about 300 mm high and has a thickness of 10 mm or more must be welded to an upper plate (10) of about 15 mm. However, if an equivalent performance is to be achieved with only a simple laminated structure of an upper plate, a lower plate, and a polymer filled in between, the thickness of the steel plates constituting the upper and lower plates alone must be 6 to 7 mm, and the thickness of the polymer filled in between would be tens to hundreds of millimeters, resulting in a very thick and heavy structure. Thickness and weight are issues, but if the thickness of the inner core exceeds about 50 mm, the heat and pressure generated during the polymer curing process may cause cracks or collapse in the middle of the core. To prevent this, metal mesh or reinforcing bars may need to be placed inside the core.

[0215] However, the plate-reinforced integrated lightweight structural material (100) proposed in the present invention not only includes the plate-reinforced structure itself, but also the spacing between vertical columns functioning as plate-reinforced materials is formed to be almost the same as the spacing of plate-reinforced materials (20) provided in conventional general steel plate structural materials, so that an optimized structure can be implemented using thin-thickness polymer and steel plates.

[0216] When the thickness, width, height, etc. of each configuration are designed within the range presented above, the lightweight structural material (100) according to the present invention can be manufactured into a long-span structure with a length of approximately 3 m to a maximum length of as much as 14 m. The reason why the lightweight structural material (100) according to the present invention can be manufactured into a long-span structure of up to 14 m is because the core layer (140) composed of a non-foaming polymer that is very lightweight compared to metal with a specific gravity of 0.8 to 1.8 is firmly bonded between the upper plate (110), the lower plate (130), and the reinforcing plate (120) to provide basic structural performance, and the vertical pillar portion formed vertically in the lightweight structural material (100) serves as a plate reinforcing material.

[0217] Another point to note here is that the lightweight structural material (100) according to the present invention, which is manufactured with a long-span structure, has excellent structural performance because it is composed of a composite material of metal and polymer. Therefore, the number of transverse reinforcements that must be installed to reinforce the transverse structure of the structural material can be significantly reduced, while exhibiting structural performance equivalent to or superior to that of general shipboard steel plate structural materials or reinforced concrete for construction. That is, while conventional general steel plate structural materials had to be configured to essentially include a transverse girder that reinforces the transverse structure separately from the plate reinforcement (20) that reinforces the longitudinal structure, the lightweight structural material (100) according to the present invention, in contrast, does not significantly require such a transverse reinforcement structure.

[0218] The lightweight structural material (100) according to the present invention can be manufactured to satisfy a predetermined deflection standard, and this deflection standard can be satisfied by forming the section modulus of the entire structure to a predetermined level or higher through adjustment / selection of the height and shape of the vertical column portion that functions as a plate reinforcement as described above.

[0219] For example, when the total length of the lightweight structural material (100) according to the present invention is 6 m, the upper plate (110), the lower plate (130), and the reinforcing plate (120) are each formed with a thickness of 1 mm, and the core layer (140) is formed with a thin core of 5 mm, the live load is 200 kgf / m. 2 If the L / 480 deflection standard is to be satisfied while forming the gap between vertical columns as 600 mm under the double-end fixing condition, the height of the vertical columns can be calculated as approximately 65 mm.

[0220] In the above deflection standard, 'L' refers to the length (span) of the lightweight structural material (100), and in order to satisfy the L / 480 deflection standard, the central portion of the lightweight structural material (100) must not sag more than 1 / 480 of the total length of the lightweight structural material (100). As in the example above, when the lightweight structural material (100) according to the present invention is manufactured to a length (span) of 6 m and both ends are fixed, the maximum deflection must be 6,000 / 480 = 12.5 (mm) or less to satisfy the L / 480 deflection standard.

[0221] That is, the structural performance of the lightweight structural material (100) to satisfy the deflection standard can be implemented by adjusting the height or shape of the vertical column.

[0222] In addition, by providing a certain level of adhesive strength or higher between the metal plates constituting the upper plate (110), lower plate (130), and reinforcing plate (120) and the core layer (140), it is possible to further assist in implementing the structural performance of the lightweight structural material (100) as described above.

[0223] The non-foaming polymer constituting the core layer (140) has adhesive strength of its own, and as described below, during the process of hardening the liquid non-foaming polymer solution, the surfaces in contact with the upper plate (110), the lower plate (130), and the reinforcing plate (120) are hermetically bonded. At this time, the present invention can provide an adhesive strength of 1 to 10 MPa, more preferably 6 MPa, between the metal plates constituting the upper plate (110), the lower plate (130), and the reinforcing plate (120) and the core layer (140).

[0224] As will be described later, the lightweight structural material (100) according to the present invention may have its side or bottom ends finished with non-metallic or metallic finishing members for structural connection with other modules in the future, or for the purpose of optimizing the structural strength required by the module itself or reinforcing fatigue strength. In this case, it is preferable that a bonding strength of at least 1 MPa (more preferably 6 MPa or more) be provided between the non-foaming polymer, which is the inner core, and the finishing member.

[0225] As described above, the lightweight structural material (100) according to the present invention has the advantage of being able to realize ultra-light weight and remarkably excellent structural performance due to its structural characteristics of being manufactured to include a plate reinforcement structure in addition to its material characteristics of being composed of a composite material of a metal material and a non-metal material (non-foaming polymer).

[0226] Specifically, the lightweight structural material (100) based on a composite material according to the present invention can implement equivalent structural performance with approximately 50 to 60% of the weight compared to a general steel plate structural material mainly used in the shipbuilding field, and can implement equivalent structural performance with approximately 15 to 25% of the weight compared to reinforced concrete mainly used in the construction field.

[0227] Furthermore, according to standard carbon emissions tables, steel and non-foaming polymers are known to generate 2-3 kg of CO2 per kilogram (kg). However, the specific gravity of non-foaming polymers is only 0.8-1.8, much lower than the specific gravity of steel (7.85). This significantly reduces carbon emissions generated during the structural manufacturing process, potentially reducing emissions by approximately 50% compared to conventional methods.

[0228] Ⅲ. Finishing and connection structure of lightweight structural material according to the present invention

[0229] Hereinafter, the finishing and connection structure of the lightweight structural material (100) according to the present invention will be examined with reference to FIGS. 21 to 23.

[0230] (1) First side end closure and connection structure

[0231] Referring to FIG. 21, in the lightweight structural material (100) according to the present invention, a first side end finishing member (151) made of a metal or non-metallic material may be inserted and placed between the upper plate (110) and the reinforcing plate (120) at both ends formed in a horizontal direction and between the lower plate (130) and the reinforcing plate (120). Here, when the first side end finishing member (151) is made of a non-metallic material, it is preferable that it be made of a material capable of producing a bonding strength of at least 1 MPa (more preferably, 6 MPa or more) with the non-foaming polymer that is the inner core.

[0232] And the adjacent lightweight structural members (100) can be joined by laser welding, such as upper plates (110), lower plates (130), and reinforcing plates (120) that are arranged to be in contact with each other. As described above, laser welding has the advantage of less thermal deformation, but has the problem that efficiency decreases as the thickness increases, making it difficult to apply to general steel plate structural members that are 6 mm or thicker. However, the present invention makes it possible to use metal plates having a thickness thinner than 6 mm (e.g., 0.4 to 5 mm) as the upper plate (110), the lower plate (130), and the reinforcing plate (120), so that application of laser welding is advantageous.

[0233] In addition, in the present embodiment, the first side end finishing member (151) can be arranged by being pushed inward by a predetermined distance into the lightweight structural member (100). Accordingly, when two or more lightweight structural members (100) are arranged so that adjacent lightweight structural members (100) are in contact with each other for connection between them, a space (S) is formed between the first side end finishing members (151) arranged on each lightweight structural member (100) facing each other, and by injecting and curing a non-foaming polymer solution (more preferably a non-foaming polyurethane solution) into the space (S), the connecting portion of the adjacent lightweight structural members (100) can be airtightly finished.

[0234] At this time, after connecting adjacent lightweight structural materials (100) by welding, a process of injecting a non-foaming polymer solution into the space (S) and curing it can be performed, and an additional effect of imparting additional bonding force between lightweight structural materials (100) by the self-adhesive force of the non-foaming polymer can also be achieved.

[0235] Meanwhile, the first side end finishing member (151) may be deleted and the non-foaming polymer core layer (140) may be left exposed. However, even in this case, it is of course possible to apply the same method of forming a predetermined space (S) at the portion where the lightweight structural material (100) is connected and injecting the non-foaming polymer solution into the space (S) to seal it airtightly.

[0236] (2) Second side end closure and connection structure

[0237] Referring to Fig. 22, a second side end finishing member (152) made of a metal material can be inserted and placed at both ends formed in a horizontal direction in a lightweight structural material (100) according to the present invention.

[0238] In this embodiment, the second side end finishing member (152) may be provided as a metal plate having a cross-section in the shape of the letter I and a thickness corresponding to the core layer (140). In the drawing, one end of the second side end finishing member (152) is inserted into the interior of the lightweight structural member (100) and the other end protrudes to the outside. However, the second side end finishing member (152) does not necessarily have to protrude to the outside, and the ends of the second side end finishing member (152) may be configured to coincide with the ends of the upper plate (110), the lower plate (130), and the reinforcing plate (120).

[0239] The second side end finishing member (152) can be structurally connected to the second side end finishing member (152) provided on the side of another adjacent lightweight structural member (100) through welding or bolting, etc.

[0240] In the case where the second side end finishing member (152) protrudes outward, the second side end finishing members (152) facing each other can be joined by welding or bolting, and in the case where the second side end finishing member (152) does not protrude outward, the entire end of the adjacent lightweight structural members (100) can be joined by welding or bolting.

[0241] In the case where the side end of the lightweight structural material (100) is finished with a metal material having a predetermined thickness as in this embodiment, there is an advantage of excellent design flexibility in that universal welding such as CO2 welding can be applied, and in addition to welding, a mechanical joining method using bolts, etc. can be applied.

[0242] (3) Third side end closure and connection structure

[0243] Referring to Fig. 23, a third side end finishing member (153) made of a metal material can be inserted and placed at both ends formed in a horizontal direction in a lightweight structural material (100) according to the present invention.

[0244] The third side end finishing and connection structure of the lightweight structural member (100) according to the present invention is similar to the second side end finishing and connection structure described just before. However, unlike the second side end finishing member (152) described above, which was formed in a simple straight shape, the third side end finishing member (153) is formed in an angle shape with a cross-section shaped like the letter 'ㄷ'.

[0245] In addition, although the drawing shows a form in which the upper surface of the third side end finishing member (153) is exposed, it may be configured so that the end of the third side end finishing member (153) and the end of the upper plate (110) and the lower plate (130) are aligned, that is, the upper plate (110) and the lower plate (130) cover both the upper surface and the lower surface of the third side end finishing member (153), respectively.

[0246] The third side end finishing member (153) can be structurally joined to the third side end finishing member (153) provided on the side of the adjacent lightweight structural member (100) by welding or bolting, etc. while in contact with each other (welding and bolting joints can also be applied together). If the upper plate (110) and the lower plate (130) are configured to cover both the third side end finishing member (153), welding can be performed between the upper plates (110) and the lower plates (130) of the adjacent lightweight structural members (100).

[0247] The finishing structure of the lightweight structural material (100) according to the present invention described above may have an additional function, such as sealing the space between the upper plate (110) and the lower plate (130) and the reinforcing plate (120) during the manufacturing process of the lightweight structural material (100), in addition to the function of assisting the bonding and connection between two or more lightweight structural materials (100).

[0248] In addition, the above finishing members (151 to 153) can be inserted between the upper plate (110) and the lower plate (130) and the reinforcing plate (120), and the surfaces that come into contact with them can be bonded by an adhesive, and the surfaces that come into contact with the core layer (140) can also be bonded by the self-adhesive force of the non-foaming polymer that forms the core layer (140). Even when the finishing members (151 to 153) are made of metal, sufficient strength can be obtained simply by inserting and bonding without the need for welding. However, in order to prevent peeling of the bonding surfaces, an adhesive strength of 1 to 10 MPa, more preferably 6 MPa, can be applied between the metal plates that constitute the upper plate (110), the lower plate (130) and the reinforcing plate (120) and the finishing members (151 to 153).

[0249] The lightweight structural material (100) according to the present invention can minimize thermal deformation by applying laser welding since the upper plate (110), lower plate (130), and reinforcing plate (120) are formed with a very thin thickness. In particular, since the core layer (140) is formed by curing after filling with a non-foaming polymer, laser welding can be performed after structural rigidity is achieved, thereby minimizing welding deformation.

[0250] In addition, since the lightweight structural material (100) according to the present invention has a reinforcing plate (120) made of metal material constituting a vertical column portion attached to the inner core layer (140) with an adhesive strength of 1 MPa or more (more preferably 6 MPa or more), it can sufficiently function as a plate reinforcing material without separate welding or with only minimal tag welding.

[0251] Ⅳ. Manufacturing method of lightweight structural material according to the present invention

[0252] Hereinafter, the manufacturing method of the lightweight structural material (100) according to the present invention will be described with reference to FIGS. 24 and 25.

[0253] The thickness of the plate reinforcement generally used in ships varies from 6 to 30 mm, but a thin thickness of approximately 6 to 15 mm is typically used. If this is replaced with the composite material structure of non-foaming polymer and metal proposed in the present invention, a metal thin plate having a thickness of approximately 1 to 3 mm is used for the upper plate (110), lower plate (130), and reinforcing plate (120), and the non-foaming polymer constituting the core layer (140) can be formed into a very thin structure having a thickness of approximately 5 to 15 mm.

[0254] However, forming a non-foaming polymer structure with such a thin thickness is not realistically easy. This is because the original solution of the non-foaming polymer has a viscosity higher than that of a lubricant before curing. Therefore, if the space to be filled is too narrow, frictional resistance makes injection difficult and even distribution within the space difficult.

[0255] According to a classification society regulation that specifies the basic performance and structural requirements of ships, when manufacturing panels made of composite materials of metal and non-foaming polymer, it is recommended that the metal plate be formed with a thickness of at least 3 mm and the core made of non-foaming polymer be formed with a thickness of at least 15 mm. If this is not followed, separate approval must be obtained.

[0256] The manufacturing methods described below are proposed to solve the manufacturing difficulties mentioned above when forming the core layer (140) of the lightweight structural material (100) according to the present invention with a non-foaming polymer, namely, the problem of difficulty in forming the core layer (140) composed of a non-foaming polymer with a thin thickness. More preferably, a method is proposed that makes it possible to obtain a uniform core layer (140) by evenly filling the space with a non-foaming polymer while forming the core layer (140) with a thickness of 15 mm or less.

[0257] Referring to Fig. 24, in manufacturing a lightweight structural material (100) according to the present invention, a method may be used in which the space between the upper plate (110), the reinforcing plate (120), and the lower plate (130) is formed as a sealed space, and a non-foaming polymer solution is injected into the space using an injection tube. At this time, in order to smoothly and evenly inject the non-foaming polymer solution, the injection tube may be divided into a plurality of small tubes.

[0258] Typically, non-foaming polymers are formed by mixing two liquid organic compounds, such as ISO and polyol, which undergo a chemical reaction and begin curing. Since this chemical reaction only takes a few minutes, the injection of the non-foaming polymer solution must also be completed within a few minutes. However, the non-foaming polymer solution itself is inherently viscous, making it difficult to spread evenly within a few minutes.

[0259] This manufacturing method is intended to solve the above-mentioned process difficulties, and divides the injection tube for injecting the non-foaming polymer raw material into several small tubes and arranges them within a space, thereby enabling the non-foaming polymer raw material to be injected quickly and evenly within the sealed space between the upper plate (110), the reinforcing plate (120), and the lower plate (130).

[0260] When applying this manufacturing method, if there is an unblocked part between the plates, a temporary dam can be used to form a sealed space, and if there is a part to be finished with a separate finishing material, the part can be sealed with the finishing material.

[0261] In addition, when injecting the non-foaming polymer solution into the space between the upper plate (110), the reinforcing plate (120), and the lower plate (130), the injection may be performed while removing the air within the sealed space using a vacuum pump. Specifically, after forming the space between the upper plate (110), the reinforcing plate (120), and the lower plate (130) into a sealed space, the non-foaming polymer solution may be injected by inserting an injection tube into one side, while the air within the sealed space may be sucked in using a vacuum pump on the other side.

[0262] As described above, when using a vacuum pump, it is possible to inject the non-foaming polymer raw material in a thin thickness while overcoming frictional resistance due to the pressure difference between the inside and outside of the sealed space between the upper plate (110), the reinforcing plate (120), and the lower plate (130). In addition, there is an advantage in that rapid injection is possible due to the suction power of the vacuum pump. Using a vacuum pump makes it possible to integrate multiple injection tubes, which can also help simplify the structure for injecting the non-foaming polymer.

[0263] Meanwhile, the upper plate (110), reinforcing plate (120), and lower plate (130) used in the production of the lightweight structural material (100) according to the present invention use metal plates that are much thinner than the steel plates used in general ship structural materials, which causes a cumbersome construction method. This is because the thickness of the metal plates is so thin that it is difficult to maintain the shape and manage the flatness of the plates before or during the process of filling the core (non-foaming polymer).

[0264] In the present invention, a spacer can be used to maintain the shape and maintain the gap during the process of filling the core between the upper plate (110), the reinforcing plate (120), and the lower plate (130). In addition, since the non-foaming polymer forming the core layer (140) has the characteristic of slightly swelling during the curing process, the upper plate (the plate placed on top during the manufacturing process) is pressed with a considerable load. However, in the lightweight structural material (100) according to the present invention, the thickness of the metal plates forming the upper plate (110), the reinforcing plate (120), and the lower plate (130) is formed very thinly below a certain level, so it may be difficult to maintain the shape and flatness of the plates only by using a spacer as described above or by pressing with a predetermined load.

[0265] In addition, the upper plate may sag due to its own weight. If the core is formed to be thick enough, the chemical reaction is strong enough to push the sagging upper plate back up using the force of the core swelling. However, since the lightweight structural material (100) according to the present invention has a thin core layer (140), the force of the core swelling is weak, and thus, it may be insufficient to restore the sagging of the upper plate due to its own weight during the manufacturing process.

[0266] In addition, the lightweight structural material (100) according to the present invention includes a structure in which the reinforcing plate (120) is bent from the horizontal direction to the vertical direction. In this case, it is also very difficult to maintain the bending angle constant due to the nature of the reinforcing plate (120) being composed of a thin plate.

[0267] To address these manufacturing difficulties, the present invention utilizes a magnet or vacuum suction device during the manufacturing process of a lightweight structural material (100). In other words, the following description relates to a method for maintaining the overall shape and flatness of a structural material during the injection and curing processes of a non-foaming polymer.

[0268] Specifically, as illustrated in FIG. 25, when a magnet (M) is placed on the upper surface of the upper plate (110) while the space between the upper plate (110), the reinforcing plate (120), and the lower plate (130) is filled with a non-foaming polymer solution, the upper surface of the upper plate (110) can be kept in a flat state by being brought into close contact with the magnet (M) due to the magnetic field generated by the magnet (M).

[0269] For reference, in the embodiment illustrated in Fig. 25, the process is carried out in a state where the lower plate (130), the reinforcing plate (120), and the upper plate (110) are sequentially stacked on a surface plate, so the magnet (M) is placed on the upper plate (110). If the upper / lower positions are reversed and the manufacturing process of the lightweight structural material (100) is carried out, the magnet (M) can be placed on the lower plate (130) located relatively higher.

[0270] Here, the term "magnet (M)" can be understood as a concept encompassing all magnetic materials capable of generating a force that attracts metals, including electromagnets. The magnet (M) need not be sized to cover the entire surface area of ​​the plate to be flattened. Even if it occupies only a portion of the surface area, the effect of flattening the entire plate can be observed. Furthermore, multiple magnets (M) can be placed on the plate, and when using only one magnet (M), it is preferable to place it in the center of the plate.

[0271] In addition, by arranging magnets (M) on the side of the reinforcing plate (120) that is erected in the vertical direction using the same principle, flatness can be maintained and a desired bending angle can be obtained. At this time, the magnets (M) can be configured to be included in a work jig or platen that fixes the position of the reinforcing plate (120). In the drawing, only the magnets (M) that apply tensile force to the reinforcing plate (120) are configured in the platen, but it goes without saying that the magnets (M) that apply tensile force to the upper plate (110) can also be configured in a separate jig or platen (not shown) for fixing the upper plate (110).

[0272] It is also possible to use a vacuum suction device instead of a magnet (M). Specifically, the vacuum suction device can maintain the shape of the structural material and maintain the flatness by suctioning a specific area of ​​the plate where the flatness is to be maintained and applying a tensile force. As in the case of using a magnet (M), the vacuum suction device can perform the function of maintaining the flatness even if it provides suction force only for a portion of the plate, not the entire area, and it is preferable to suction the central area of ​​the plate where the flatness is to be maintained. Furthermore, it is also possible to apply multiple vacuum suction devices to a single plate.

[0273] The lightweight structural material (100) of the present invention manufactured through this process can realize uniform structural performance by maintaining a flat surface and an overall uniform thickness. In addition, since the flatness issue is resolved during the manufacturing process, the amount of spacers arranged between the upper plate (110), the reinforcing plate (120), and the lower plate (130) can be significantly reduced, thereby achieving the effect of reducing manufacturing man-hours and costs.

[0274] Meanwhile, in the process of manufacturing a lightweight structural material (100) according to the present invention, a spacer may be placed between the upper plate (110), the lower plate (130), and the reinforcing plate (120), and between the reinforcing plates (120) facing each other, that is, between the metal plate components, to maintain a constant gap between the two plates. At this time, the spacer may be composed of a material having an adhesive strength of 3 MPa or more with the polymer that constitutes the core layer (140).

[0275] Additionally, thin, non-foaming polymers require less time to cure than thick, non-foaming polymers because their absolute capacity for chemical reaction is lower. This can lead to slower intermolecular chemical reactions, particularly in colder climates like winter, which can further delay curing or, in extreme cases, prevent curing altogether. To prevent this, heating elements or heating pipes may be added to the work surface to raise the temperature.

[0276] V. Specific production method

[0277] Hereinafter, a specific example of a method for manufacturing a lightweight structural material (100) according to the present invention will be described. The manufacturing example described below relates to a case in which the 'second side end finishing structure' described with reference to FIG. 22 is applied.

[0278] First, the components shown in FIGS. 26 to 29 are prepared as materials for manufacturing a lightweight structural member (100). FIG. 26 illustrates an upper plate (110) and a lower plate (130), and FIG. 27 illustrates a plurality of first reinforcing plates (120c) and second reinforcing plates (120d) constituting a reinforcing plate (120). FIGS. 28 and 29 illustrate elements constituting a perimeter bar (160) that functions as a finishing member for finishing between the lower plate (130) and the reinforcing plate (120), between adjacent reinforcing plates (120), and between the upper plate (110) and the reinforcing plate (120) in the lightweight structural member (100).

[0279] Referring to Fig. 26, the upper plate (110) and the lower plate (130) are provided in the form of flat square plates. In the present embodiment, the lower plate (130) has a simple square shape, while the upper plate (110) may be configured to include protruding portions at the front / rear edges along the length direction. This artificially forms a space so that when two lightweight structural members (100) that have been manufactured are connected to each other in the length direction, welding can also be performed at the lower end.

[0280] That is, it can be seen that protrusions are formed at the front / rear corners of the top plate (110), but it can also be seen that square grooves are dug inward at the front / rear corners of the top plate (110), and when two lightweight structural members (100) that have been manufactured are connected longitudinally, the grooves provided on each face each other to form a space into which welding equipment can be inserted. This will be examined in more detail later with reference to FIGS. 39 and 40.

[0281] The upper plate (110) may be provided so that its entire length, including the protruding portion, corresponds to the length of the lower plate (130). Since the protruding structure described above is not required in the transverse direction of the upper plate (110), the width of the upper plate (110) may be provided to be the same as the width of the lower plate (130).

[0282] Referring to Fig. 27, the reinforcing plate (120) may be composed of a first reinforcing plate (120c) having a 'ㄷ' shaped cross-section and a second reinforcing plate (120d) having a 'ㅁ' shaped cross-section. The first reinforcing plate (120c) has a form in which one edge of the plate formed horizontally through two bending processes is bent vertically and then bent again horizontally. The second reinforcing plate (120d) has a roughly hollow square pipe shape with front / rear sides open along the length direction, and a hexahedral-shaped empty space may be formed inside.

[0283] In this embodiment, two first reinforcing plates (120c) are provided so as to be arranged at each end along the width direction of the lightweight structural member (100), and the number of second reinforcing plates (120d) provided between them may vary depending on the number of plate reinforcing structures (vertical column sections) to be formed. In this embodiment, five plate reinforcing structures (vertical column sections) are formed in one unit of the lightweight structural member (100), and four second reinforcing plates (120d) are used for this purpose.

[0284] The perimeter bar (160) installed on the perimeter between the upper plate (110) and the lower plate (130) and functioning as a finishing member can be configured to include the lower perimeter bar (161) and vertical bar (162) illustrated in FIG. 28, and the upper perimeter bar (163) illustrated in FIG. 29. In this embodiment, the upper perimeter bar (163) is illustrated separately from other components, but since all components (161 to 163) constituting the perimeter bar (160) are joined by welding, the three components (161 to 163) may be manufactured as an integral structure.

[0285] The lower edge bar (161) is placed on the edge between the lower plate (130) and the reinforcing plate (120) and serves as the second side end finishing member (152; see Fig. 22) described above.

[0286] The vertical bar (162) is installed vertically at a certain point on the lower edge bar (161) and serves to finish the vertical reinforcement part (vertical column part) formed by the reinforcement plate (120).

[0287] The vertical bar (162) can be installed at a position where a vertical column portion that functions as a plate reinforcement is formed in the lightweight structural member (100). Since the present embodiment relates to a structure in which five vertical column portions are formed in one unit of the lightweight structural member (100), the vertical bars (162) can be installed at five points respectively along the width direction. In addition, the lower edge bar (161) in the present embodiment is a bar in which a pair of long metal plates are installed in parallel along the length direction and the width direction to form a square frame shape, and the vertical bars (162) can be installed at a total of ten points, five points each at the front and rear along the length direction.

[0288] The upper edge bar (163) is positioned at the edge between the upper plate (110) and the reinforcing plate (120) and functions as the second side end finishing member (152; see Fig. 22) described above. The upper edge bar (163) may include a square-shaped protruding portion at the front / rear along the length direction so as to correspond to the shape of the upper plate (110).

[0289] Each of the above elements (161 to 163) constituting the perimeter bar (160) may be provided as a metal plate having a predetermined thickness.

[0290] Hereinafter, a method for manufacturing a lightweight structural material (100) according to the present invention using the components prepared as described above will be examined in sequential steps.

[0291] Referring to Fig. 30, first, the lower edge bar (161) is placed and fixed on the lower plate (130). At this time, the lower edge bar (161) formed in a square frame shape is placed on the edge along the square circumference of the lower plate (130). In the present embodiment, the end of the lower edge bar (161) is aligned with the end of the edge of the lower plate (130), but the end of the lower edge bar (161) may be placed so as to protrude slightly more than the end of the edge of the lower plate (130).

[0292] The lower edge bar (161) can be joined to the lower plate (130) through laser welding. Since the lower edge bar (161) can be provided with bonding strength by the self-adhesive strength of the non-foaming polymer that will later form the core layer (140), at this stage, it is sufficient to simply fix it to the lower plate (130) using a sheet metal adhesive tape or the like instead of laser welding. However, the fixing strength must be provided to a degree that can withstand the pressure of the non-foaming polymer solution rising and the expansion pressure during hardening. This also applies to the bonding between the reinforcing plate (120) and the vertical bar (162) described later, and the bonding between the upper plate (110) and the upper edge bar (163).

[0293] Next, the upper border bar (163) is placed and fixed on top of the lower border bar (161) and the vertical bar (162). The upper border bar (163) is formed in a square frame shape similar to the lower border bar (161), but has protruding portions at the front and rear along the length direction. At this time, the protruding portion can be welded to the upper end of the vertical bar (162) to form a joint.

[0294] Next, referring to FIG. 31, a plurality of reinforcing plates (120) including a first reinforcing plate (120c) and a second reinforcing plate (120d) are placed on the lower plate (130). At this time, the reinforcing plates (120) may be placed in a form that is inserted into a structure formed by a perimeter bar (160). Since the thickness of each component (161 to 163) forming the perimeter bar (160) corresponds to the thickness at which the core layer (140) is to be formed, the reinforcing plates (120) may be placed so as to be in contact with the perimeter bar (160).

[0295] Although not shown in the drawing, a plurality of spacers (not shown) may be placed between the lower plate (130) and the reinforcing plate (120) and between adjacent reinforcing plates (120) facing each other for the purpose of maintaining a gap.

[0296] Referring to Fig. 32, it can be confirmed that the arrangement of the reinforcing plates (120; 120c, 120d) is complete. Figs. 33a and 33b are enlarged views of the portions indicated as 'A' and 'B' in Fig. 32, respectively. After assembling a plurality of reinforcing plates (120) in a sliding manner, the end portions where the reinforcing plates (120) and the perimeter bar (160) come into contact can be joined by laser welding.

[0297] Next, referring to FIG. 34, an additional operation of arranging metal reinforcements (142) at necessary locations above the space where the reinforcing plates (120) are arranged may be performed. For example, in the present embodiment, metal reinforcements (142) are arranged in a cross shape corresponding to locations where longitudinal girders and transverse girders will be welded on the outer surface of a lightweight structural member (100) that will be manufactured in the future. This arrangement enables strong welding of the longitudinal and transverse girders to be welded in the future, and serves to prevent internal polymer from burning during welding.

[0298] Except for the space where the metal reinforcement (142) is placed, the remaining space is then filled with a non-foaming polymer to form a core layer (140), and the metal reinforcement (142) after the manufacturing is completed can be firmly fixed by the self-adhesive force of the polymer forming the core layer (140). Therefore, in the step of placing the metal reinforcement (142), there is no need to firmly fix the metal reinforcement (142) to the reinforcement plate (120) or perimeter bar (160) by welding, and it is sufficient to temporarily fix it using a steel plate adhesive tape or the like.

[0299] Thereafter, as illustrated in Fig. 35, the upper plate (110) is covered, and the portion where the upper plate (110) and the upper edge bar (163) come into contact is fixed through laser welding. A plurality of spacers (not illustrated) may be placed between the upper plate (110) and the reinforcing plate (120) for the purpose of maintaining a constant gap between the two plates.

[0300] When the arrangement and configuration of the upper plate (110), the reinforcing plate (120), the lower plate (130), and the perimeter bar (160) are completed as described above, a non-foaming polymer solution is injected into the space formed between them and cured.

[0301] More specifically, the lower plate (130) and the reinforcing plate (120) are spaced apart from each other by a distance corresponding to the thickness of the lower perimeter bar (161), and a space is formed therebetween. In addition, a plurality of reinforcing plates (120) are spaced apart from each other by a distance corresponding to the thickness of the vertical bar (162), and a space is formed therebetween. In addition, the upper plate (110) and the reinforcing plate (120) are spaced apart from each other by a distance corresponding to the thickness of the upper perimeter bar (163), and a space is formed therebetween. The spaces form a space sealed by the perimeter bar (160), and a non-foaming polymer solution is injected into the space and cured to form the core layer (140).

[0302] In the process of manufacturing the lightweight structural material (100) according to the present invention, it is preferable that the upper plate (110), the lower plate (130), the reinforcing plate (120), and the perimeter bar (160) are joined to each other through laser welding; however, if the positions can be mechanically fixed through a work jig or a tabletop, it is sufficient to join the above-mentioned components with only a weak force using an adhesive tape (e.g., 3M VHB tape) or other adhesive.

[0303] In order to inject a non-foaming polymer solution into the space formed by the upper plate (110), the reinforcing plate (120), the lower plate (130), and the perimeter bar (160), an injection hole communicating with the internal space and a vent hole for venting air within the space may be formed at a predetermined position. In addition, a plurality of injection tubes, as illustrated in FIG. 24, may be arranged within the space to inject the non-foaming polymer solution, and a vacuum pump may be used to induce more rapid and effective injection of the non-foaming polymer solution.

[0304] In addition, in order to prevent the plate from swelling or warping due to expansion pressure when the non-foaming polymer solution is cured, a method such as pressing the plate on top during the manufacturing process or placing a magnet (M) on the upper surface of the plate as described with reference to FIG. 25 can be used.

[0305] As the non-foaming polymer solution hardens, the formation of the core layer (140) is completed.

[0306] The structure of the lightweight structural material (100) manufactured through the above process is illustrated in Fig. 36. Fig. 37 is an enlarged view of the portion indicated by 'C' in Fig. 36. This embodiment presents a structure in which five vertical pillars are formed in one unit of the lightweight structural material (100), but as mentioned above, the number of vertical pillars may be changed depending on the required structural performance of the lightweight structural material (100).

[0307] Figures 38 and 39 are drawings showing the transverse connection structure and longitudinal connection structure of the lightweight structural material (100) according to the present invention, respectively.

[0308] Referring to Fig. 38, in the case of transverse joining, adjacent lightweight structural members (100) can be joined by straight welding (more preferably laser welding) the upper and lower parts while facing each other.

[0309] Referring to FIGS. 39 and 40, in the case of longitudinal joining, when adjacent lightweight structural members (100) are placed against each other, the lower ends are exposed by a square-shaped groove formed at the edge of the upper plate (110), and welding equipment can be inserted through the space exposed in this manner to perform welding between the lower ends of the lightweight structural members (100). In addition, the protruding portions formed on the upper plates (110) facing each other are welded to connect the parts where they touch each other.

[0310] Ⅵ. Application examples of lightweight structural materials according to the present invention

[0311] The lightweight structural material (100) according to the present invention can be utilized to form the floor, ceiling, and wall structures of a ship structure or a building.

[0312] Preferably, the lightweight structural material (100) according to the present invention can be used as a deck structure for a ship. Furthermore, the lightweight structural material (100) according to the present invention can be installed above or below a concrete slab that divides the upper and lower floors of a building and used as a floor or ceiling structure. It goes without saying that it can also be applied to the wall structure of a building, if necessary.

[0313] Hereinafter, specific application examples of the lightweight structural material (100) according to the present invention and the resulting operational effects will be examined in more detail.

[0314] (1) Ship sector

[0315] The lightweight structural material (100) according to the present invention can be effectively utilized in constructing structures installed on ships. The lightweight structural material (100) according to the present invention is expected to be highly useful in the shipbuilding field, particularly when used in the construction of car decks for pure car carriers (PCCs). Furthermore, it can be very effectively utilized in constructing structures such as wind deflectors installed on container ships to block wind and waves, or ship accommodations.

[0316] In addition, the lightweight structural material (100) according to the present invention can be used to implement a cofferdam or rudder for a ship and a cell guide structure for a container ship. These three application examples will be examined in detail for each embodiment below.

[0317] A. Use as a cofferdam structure

[0318] A cofferdam is a buffer space constructed using double bulkheads to prevent the direct infiltration of gases, oil, liquids, etc. from one compartment to another. According to relevant regulations, cofferdams must be constructed with double bulkheads spaced at least 600 mm apart to allow for regular inspection and maintenance. However, in practice, due to difficulties in construction and other aspects, cofferdams often occupy a space of 800 to 900 mm.

[0319] By utilizing the lightweight structural material (100) of the present invention to implement a cofferdam structure of a ship, the above-mentioned conventional problem, i.e., the problem of space utilization, can be solved, and the manufacturing and installation efficiency can also be excellent.

[0320] For example, the installation of a cofferdam structure can be accomplished very easily by simply erecting the completed lightweight structural material (100) as shown in Fig. 36 in a vertical direction inside the hull and connecting the upper and lower parts to the hull structure.

[0321] When the lightweight structural material (100) according to the present invention is used as a cofferdam structure, the 'upper flat plate portion' and the 'lower flat plate portion', which serve as structural members as described above, each perform the role of a bulkhead. That is, the lightweight structural material (100) of the present invention can perform the role of a double bulkhead by including a plate reinforcement structure and a multi-shielding structure between the upper plate (110) and the lower plate (130).

[0322] As described above, the lightweight structural material (100) according to the present invention is manufactured by injecting a liquid polymer between metal plates and curing it. During the curing process of the polymer, the temperature rises, generating a significant expansion pressure in the inner core space. The pressure at this time is so strong that the polymer will spurt out even if there is a very fine hole in the outer metal plate. Therefore, the composite structure of metal-polymer-metal forming the lightweight structural material (100) according to the present invention can be implemented as a perfect triple shielding structure. In fact, since international classification societies are also tending to recognize that such a multi-shielding structure has the same shielding performance as a conventional cofferdam, it is expected that the classification rules can also be sufficiently satisfied.

[0323] More specifically, the lightweight structural material (100) according to the present invention has a triple shielding structure in each of the upper flat plate portion and the lower flat plate portion, so that it has a total of six layers of shielding structure.

[0324] And since the lightweight structural material (100) according to the present invention includes a space portion in the reinforcing plate (120) placed inside, it can be seen that the internal space (Void) required by the cofferdam is automatically formed, and thus has the advantage of excellent installability.

[0325] Using conventional methods, a double bulkhead must be built to install a cofferdam. This reduces workability due to the confined space involved, and safety issues may arise due to welding within a confined space.

[0326] However, when applying the present invention, since a box-type lightweight structural material (100) is separately manufactured at a factory and only welding is performed at the connection part with the hull at the site, the effect of workability being incomparably improved compared to the conventional method can be enjoyed.

[0327] Meanwhile, the double bulkheads forming the cofferdam require a spacing of at least 600 mm, but typically occupy a space of approximately 800 to 900 mm, taking the working environment into consideration. However, since the lightweight structural material (100) according to the present invention has a six-layer shielding structure, there is a high possibility that more relaxed regulatory standards than the above will be applied. Since the lightweight structural material (100) according to the present invention is typically manufactured as a single panel with a thickness of 100 to 200 mm, it is expected that an additional space of at least 400 mm and at most 800 mm can be secured.

[0328] In addition, all the effects of the lightweight structural material (100) according to the present invention can be realized as is. For example, a weight reduction effect of approximately 30 to 40% can be expected, and as the overall weight is reduced, the amount of steel plate used is reduced by more than 40%, and since a relatively small weight of polymer is used, the overall carbon emissions can be reduced by approximately 40 to 50%.

[0329] Meanwhile, when installing the lightweight structural material (100) according to the present invention as a cofferdam structure, a method for easily doubling the shielding of the connection portion with the hull can be presented as shown in FIG. 41.

[0330] Referring to Fig. 41, the lower part of the upper plate (110) and the lower part of the lower plate (130) are welded to the hull deck, and a polymer can be injected on-site (i.e., injected upon installation on the hull) into the sealed space formed at the lower part between the reinforcing plates (120) to harden it, thereby further increasing the shielding at the connection part. However, the core layer (140a) formed in the space between the upper plate (110) and the reinforcing plate (120) and the space between the lower plate (130) and the reinforcing plate (120) can be formed in advance during manufacturing at the factory, and only the core layer (140b) formed in the part in contact with the hull deck can be formed by the on-site injection method. This can also be applied to the upper part connected to another hull part.

[0331] Conventional cofferdams inevitably involve welded structures at the upper and lower ends, making these areas vulnerable to liquid-tightness and airtightness. However, the present invention offers the advantage of easily addressing this vulnerability by enhancing shielding at the connection points, as described above. The aforementioned structure for enhancing shielding at the connection points is not mandatory and is optional.

[0332] Meanwhile, a cofferdam may require that the internal space be connected as a single, uninterrupted space to allow for inspection of the space formed within it. To this end, when utilizing the lightweight structural material (100) according to the present invention as a cofferdam structure, the structure may be constructed so that the spaces formed within each of the multiple reinforcing plates (120) are interconnected, as illustrated in FIG. 42.

[0333] Referring to FIG. 42, the lightweight structural material (100) of the present invention may further include a plurality of reinforcing plates (120) and a separator plate (164) that is arranged vertically to form an internal space (Void) together with the reinforcing plates (120). In addition, two holes (H1, H2) may be formed in the plurality of reinforcing plates (120). The first hole (H1) and the second hole (H2) are formed on opposite sides of the separator plate (164), the second hole (H2) is formed on the side of the internal space (Void) of the reinforcing plate (120), and the first hole (H1) may be formed in the protrusion (165) on the opposite side. A polymer may be injected in situ through the first hole (H1), and the internal spaces of the reinforcing plates (120) may be communicated with each other through the second hole (H2).

[0334] B. Use as a rudder structure

[0335] By utilizing the lightweight structural material (100) of the present invention, a structure that is formed in a streamlined shape and generates lift, such as a ship's rudder or an aircraft's wing, can be manufactured more robustly and simply.

[0336] Fig. 43a illustrates butt welding, Fig. 43b illustrates slot welding, and Fig. 43c illustrates a rudder structure of a conventional ship.

[0337] Referring to Fig. 43c, the rudder of a conventional ship is typically structured such that a first side plate (51) and a second side plate (52) form the body, and a number of horizontal reinforcement members (53) and vertical reinforcement members (54) are installed inside to support the structure when a load is applied.

[0338] When manufacturing such a conventional rudder structure, if the first side plate (51) is welded first and then the second side plate (52) is joined by welding, since the welding of the first side plate (51) is performed with the opposite side open, sufficient working space is secured, enabling a sturdy butt welding (Fig. 43a). On the other hand, in the case of the second side plate (52), it is difficult to secure a working space, making it difficult to perform a sturdy welding. Therefore, it is common to adopt a slot welding method (Fig. 43b) in which a hole is partially drilled in the plate, a welding bead is formed in the hole, and then the second side plate (52), which is joined later, is welded to the horizontal and vertical reinforcements (53, 54) inside.

[0339] However, this type of slot welding method has a weaker bonding strength than butt welding, so cracks can occur due to vibration or load, and fluids such as water can flow into the unwelded area, causing corrosion.

[0340] In addition, slot welding requires additional welding of flanges, which increases weight and requires more work time. In addition, the welding heat generated during the welding process of horizontal and vertical reinforcements (53, 54) may cause deformation of the skin plate of the second side plate (52) constituting the body of the rudder. This can be particularly problematic in structures where a streamlined shape is very important for generating lift and reducing cavitation, such as the rudder of a ship or the wing of an aircraft.

[0341] In contrast, the lightweight structural material (100) according to the present invention does not require welding of a plate reinforcement structure and is easy to bend due to its characteristic of being manufactured with a thin metal plate, so that a curved structure such as a ship's rudder or an aircraft's wing can be easily implemented.

[0342] FIG. 44 is a drawing showing an example of utilizing a lightweight structural material according to the present invention as a rudder structure of a ship, and FIG. 45 is a drawing showing a cross-section along line AB of the rudder structure shown in FIG. 44.

[0343] Referring to FIGS. 44 and 45, a rudder structure can be manufactured by applying the same method for manufacturing a lightweight structural material (100) according to the present invention. Specifically, a plurality of box-shaped reinforcing plates (120) having a polygonal cross-section structure inside are arranged at predetermined intervals (can be arranged in two or more rows and two or more layers), and an upper plate (110) and a lower plate (130) are arranged as skin plates on both sides and joined, and then a non-foaming polymer is injected in a liquid state into the space between the upper plate (110), the lower plate (130), and the reinforcing plate (120) and hardened, thereby making it possible to manufacture a rudder structure having a solid internal reinforcing structure.

[0344] The upper plate (110) and the lower plate (130) may be formed as curved plates having a curvature, and may have a streamlined shape in which the ends are joined to each other to generate lift. In this case, the ends of the upper plate (110) and the lower plate (130) may be directly joined by contacting each other, but may also be joined via another plate.

[0345] When manufacturing is carried out in the above manner, welding is performed only at the edges of the upper plate (110) and lower plate (130) forming both sides of the structure, so there is no problem with workability at all. In addition, since the upper plate (110) and lower plate (130) are joined with sufficient bonding strength by the core layer (140) formed by injecting and curing a non-foaming polymer therein, there is no need to weld with internal reinforcing materials as in the past, so that the overall workability can be significantly improved.

[0346] That is, the lightweight structural material (100) according to the present invention can easily implement vertical and horizontal skeletal structures formed inside the rudder by injecting and hardening a non-foaming polymer into the space between the upper plate (110), the lower plate (130), and the reinforcing plate (120).

[0347] In addition, it is important that structures such as a ship's rudder or an aircraft's wing be manufactured as a sealed structure to generate lift. As described above, if a rudder structure is implemented using the lightweight structural material (100) according to the present invention, it is easy to form a sealed structure by the core layer (140) injected and hardened in the internal space.

[0348] C. Use as a cell guide structure for container ships

[0349] The lightweight structural material (100) according to the present invention can also be manufactured in a form in which a single protrusion protrudes in a direction perpendicular to the flat portion, and the lightweight structural material (100) of this form can be very usefully used as a cell guide structure of a container ship.

[0350] Cell guides are provided for efficient container loading on container ships. They are installed at regular intervals on the transverse bulkhead or web frame of the cargo hold of a container ship and serve to guide the loading of containers.

[0351] Conventional cell guides are constructed by placing two L-shaped metal angles, each approximately 10 to 15 mm thick, against each other and welding a metal intermediate reinforcement between them. These basic cell guides are transported to the shipyard's installation site and then installed on the deck of a container ship at intervals of approximately 3 to 5 meters in the vertical direction.

[0352] However, the conventional method requires welding thousands of intermediate reinforcements per container ship, a cumbersome process. These intermediate reinforcements must be spaced approximately 1 meter apart to maintain the basic angle shape. However, as container ships have become larger, the size of cargo holds has also increased, necessitating the welding of a massive number of intermediate reinforcements.

[0353] Because automated welding is virtually impossible for thousands of intermediate reinforcements, manual welding is primarily used, resulting in significant labor time. Furthermore, the heat generated when welding thousands of intermediate reinforcements frequently causes welding deformation, such as distortion of the entire cell guide structure. This requires additional work to correct this distortion.

[0354] As such, conventional cell guide structures suffer from a critical problem: poor accuracy. Cell guides are structures that hold the positions of containers loaded onto container ships, so accuracy control in their dimensions and shape is crucial. Even a few millimeters of error can prevent containers from smoothly sliding down the cell guides. This can damage the container or the cell guides during descent, or even cause them to get caught midway. Furthermore, conventional cell guides lack any additional reinforcement beyond intermediate reinforcement between the angled sections, making them prone to bending due to impacts during loading.

[0355] However, when the lightweight structural material (100) according to the present invention is used as a cell guide structure of a container ship, the following effects can be achieved.

[0356] In the present invention, the cell guide using a lightweight structural material (100) is manufactured as a single composite structure rather than being manufactured in a manner in which angles and intermediate reinforcements are manufactured separately, so that there are no thousands of intermediate reinforcements included in the conventional cell guide, and thus the welding work required is significantly reduced, thereby saving a great deal of labor time and cost.

[0357] In addition, the weight can be significantly reduced. While conventional cell guides typically use metal angles with a thickness of 10 to 15 mm, when using the lightweight structural material (100) according to the present invention, the outer plate is composed of a thin plate with a thickness of 2 to 5 mm and a lightweight polymer is injected into the interior, so the overall weight of the cell guide structure can be reduced by about 30% or more compared to conventional structures.

[0358] In particular, when the lightweight structural material (100) according to the present invention is used as a cell guide structure, the welding deformation that occurs when welding a conventional intermediate reinforcement material does not occur, so it has an excellent effect in terms of quality control when manufacturing the cell guide.

[0359] In addition, since the lightweight structural material (100) according to the present invention has a structure in which polymer is uniformly injected throughout the entire structure, it has excellent durability because there is no structural vulnerability between angle structures like in the conventional cell guide.

[0360] As seen above, when the lightweight structural material (100) according to the present invention is used as a ship structural material, the effect of solving the existing welding thermal deformation problem can be achieved.

[0361] In the past, general steel plate structural materials of the type shown in Fig. 1 were mainly used to construct the deck of a ship, and in this case, it was described in the background art that the problem of serious thermal deformation could not be avoided as the plate reinforcement (20) was welded under the top plate (10) that served as a structural member. In addition, if only the structural performance of a typical ship deck is considered, the top plate (10) of the steel plate structural material should be formed to a thickness of approximately 6 mm. However, considering the thermal deformation due to the welding of the plate reinforcement (20), the thickness of the top plate (10) is frequently increased to approximately 10 mm from the beginning and manufactured. However, even if the thickness of the top plate (10) is increased, the problem of thermal deformation due to the welding of the plate reinforcement (20) still exists, and therefore, in most cases, a considerable amount of time is invested in corrective work through heat processing after the welding of the plate reinforcement (20).

[0362] However, the lightweight structural material (100) according to the present invention has a vertical column portion that functions as a plate reinforcement already included in the structure, and thus does not require welding for attachment of the plate reinforcement, so that the amount of welding required for the entire process and the resulting thermal deformation can be greatly reduced, and thus the problem of thermal deformation due to welding of steel plate structural materials that are still mainly used in the shipbuilding industry can be fundamentally solved.

[0363] In addition, when connecting adjacent lightweight structural materials (100) according to the present invention, since welding is performed between metallic finishing members or between lightweight structural materials (100) whose rigidity has already been secured by a core layer (140) formed inside, the amount of thermal deformation of the entire plate can be greatly reduced.

[0364] In addition, the lightweight structural material (100) according to the present invention, which is composed of a composite material, can achieve equivalent structural performance with a weight that is approximately 40 to 50% lighter than that of existing steel plates, and thus can greatly contribute to reducing the weight of ships.

[0365] (2) Construction sector

[0366] The lightweight structural material (100) according to the present invention has a thermal conductivity of 0.2 to 0.4 W / mK, similar to that of high-density wood, since most of its internal space is filled with a non-foaming polymer. This means that it has incomparably superior insulation performance compared to general steel plate structural materials (k=83 W / mK) mainly used for ships, and has even superior insulation performance compared to reinforced concrete (k=1.6 W / mK) used for construction. In addition, the lightweight structural material (100) according to the present invention has excellent performance in terms of vibration / noise reduction due to the role of the elastic non-foaming polymer, and therefore can be sufficiently used not only as a structural material for ships but also as a floor or wall structure for land.

[0367] Representatively, the longitudinal ends of the lightweight structural material (100) according to the present invention can be structurally connected to a wall to form a floor or ceiling structure of a building.

[0368] Specifically, the lightweight structural material (100) according to the present invention can be used in the floor structure of a building, and in particular, since it can be manufactured in a long-span structure, it can be very usefully utilized in forming a double floor structure of a building. The lightweight structural material based on composite materials can be overlapped and arranged at a predetermined interval to form a double floor structure.

[0369] Typically, multi-story buildings like apartments, houses, officetels, and other buildings are separated by concrete slabs between the upper and lower floors. These slabs serve as floors on the upper floors and ceilings on the lower floors. In other words, a typical multi-story building is structured so that the upper floor's floor structure serves as the lower floor's ceiling structure. Because a single concrete slab is shared between two floors, this structure is fundamentally vulnerable to noise transmission.

[0370] The most widely used method to solve this inter-floor noise problem is the double floor structure. The conventional double floor structure, which is generally known, is a structure that installs another lightweight floor on top of a concrete slab, that is, it forms two floors and places an air layer between them to block sound transmission.

[0371] However, these conventional double-floor structures require dozens to hundreds of supports to support the lightweight floor and concrete slab, as the structural strength of the lightweight floor is not as strong as that of a concrete floor. Consequently, the transmission of noise and vibration through these numerous supports cannot be ignored. Furthermore, the numerous supports required increase installation time and costs.

[0372] However, since the lightweight structural material (100) according to the present invention can be manufactured as a long-span structure, sufficient structural performance can be secured simply by fixing both ends along the length direction to the building wall, and thus, a sturdy and perfect double floor structure can be implemented without a separate lower support structure.

[0373] That is, when a lightweight structural material (100) according to the present invention is formed as an upper floor to implement a double floor structure of a building, there is no need to install a separate support for supporting the lightweight structural material (100) on a concrete slab, and therefore, the upper floor and the concrete slab are structurally completely separated, enabling implementation of a double floor structure that is very effective in reducing inter-floor noise.

[0374] A lightweight composite material-based structure and a concrete or wooden structure can be placed at regular intervals to form a double floor structure.

[0375] Meanwhile, the lightweight structural material (100) according to the present invention can be installed under a concrete slab and utilized as a ceiling structure of the lower floor. In this case, the ceiling finishing material of the lower floor can be directly attached to the lower surface of the lightweight structural material (100), so that separate support construction and carpentry work for attaching the ceiling finishing material are not required, thereby simplifying the ceiling construction. In addition, since various pipes and decorative items (e.g., ceiling-type air conditioners) to be installed on the ceiling can be easily attached to the lightweight structural material (100) according to the present invention, the application of a modular construction method through prior decoration is also possible.

[0376] When the lightweight structural material (100) according to the present invention is used as a building structural material, the following effects can be expected.

[0377] First, it is possible to implement an ultra-lightweight long-span dry structure with superior structural performance, and its use can significantly increase the efficiency of overall construction work.

[0378] During construction, reinforced concrete floor construction is the most cumbersome and time-consuming basic skeletal work of the entire project. Because it is constructed using wet construction methods, which are highly susceptible to environmental influences and often subject to harsh on-site conditions, it is considered a crucial project from a construction management and performance perspective. Recently, there have been cases where excessive wet concrete slab construction, aimed at shortening the construction period, resulted in serious accidents.

[0379] The lightweight structural material (100) proposed in the present invention weighs only 30-40% of general concrete, but enables the implementation of a long-span structure that is much longer than existing reinforced concrete floor structures. Furthermore, since construction can be accomplished using a dry method, it is virtually immune to environmental influences, thereby significantly reducing cumbersome and harsh on-site processes. Furthermore, unlike wet methods, structural performance is realized immediately after installation, significantly shortening the overall construction period.

[0380] In addition, by using the lightweight structural material (100) according to the present invention, it is possible to implement a sturdy double floor structure that does not require a support, and thus, the problem of inter-floor noise, which has become a major social issue, can be reduced in a very groundbreaking way.

[0381] In addition, when the lightweight structural material (100) according to the present invention is used as the floor structure of a building, the insulation construction for ondol can be simplified. Since the lightweight structural material (100) according to the present invention has significantly superior structural performance, there is no need to construct ondol construction (heating construction) on the lightweight floor to increase structural strength, as in the case of the existing double floor structure. Therefore, when the lightweight structural material (100) according to the present invention is installed on an existing concrete slab, hot water piping or heating and cooling piping work required for ondol construction can be conveniently performed on the existing concrete, and there is an advantage in that there is no need to perform separate insulation mortar work.

[0382] In the past, the insulation for ondol was installed on a concrete slab and then hot water pipes were laid. Therefore, in order to create a flat floor that could be walked on, floor mortar work had to be performed or separate dry ondol panels had to be additionally installed before the finishing flooring could be constructed.

[0383] However, since the lightweight structural material (100) according to the present invention performs the function as a sufficient structural material in itself, there is no need for separate floor mortar work or dry ondol panel installation work that was performed in the past, and since finishing floor material can be constructed directly on the lightweight structural material (100), ondol insulation construction can be made much simpler.

[0384] Step construction can also be simplified. Typically, bathroom or entrance floors are designed to have a step height that is several tens of millimeters (mm) lower than other floor slabs. Conventional construction methods require separate formwork or ventilation work to create such a step height. However, according to the present invention, all floor slabs on the same floor are manufactured flat and the step height is only applied to the lightweight structural material (100), which simplifies step construction and greatly facilitates the production of step structures for bathroom or entrance floor slabs.

[0385] In addition, when the lightweight structural material (100) according to the present invention is used as a ceiling structure of a building, the ceiling finishing material of the lower floor can be directly attached to the lower surface of the lightweight structural material (100), thereby simplifying the ceiling construction, and application of the modular construction method is also possible through pre-attaching various pipes and decorations to be installed on the ceiling to the lightweight structural material (100).

[0386] (3) Other fields

[0387] The lightweight structural material (100) according to the present invention is expected to be usefully applied as a structural material for constructing explosion-proof containers or high-pressure pressure vessels that must withstand strong impact loads due to explosions, as it is lightweight and has excellent structural performance.

[0388] The lightweight structural material (100) according to the present invention can be formed into a multi-deck structure (Figs. 5 and 6) and used as a multi-deck container for storing and transporting heavy objects in the internal space. In particular, the lightweight structural material (100) according to the present invention has excellent structural performance to the extent that it can withstand strong impact loads due to explosions, and thus can be usefully utilized as a waste battery container for storing and transporting waste batteries, the demand for which is rapidly increasing along with the rapid growth of the electric vehicle market.

[0389] Typically, explosion-proof containers or pressure vessels are manufactured in a spherical or cylindrical shape to withstand internal pressure well. However, the lightweight structural material (100) according to the present invention is structurally very strong due to its characteristic of being composed of composite materials, and since the wall and the plate reinforcement structure formed inside (used as a deck when used as a container) are configured in a continuous shape, significantly superior structural performance can be realized. Therefore, by using the lightweight structural material (100) according to the present invention, the shape of the explosion-proof container or pressure vessel is not limited to a spherical or cylindrical shape, and it becomes possible to manufacture it in an angular shape including a hexahedron.

[0390] The present invention is not limited to the described embodiments, and it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Accordingly, such modifications or variations should fall within the scope of the claims of the present invention.

Claims

1. First abacus; A second board arranged at a predetermined distance from the first board; A plurality of reinforcing plates arranged between the first main plate and the second main plate and having one or more bends; and It includes a core layer formed in the space between the first main plate and the reinforcing plate, the space between the second main plate and the reinforcing plate, and the space between the adjacent reinforcing plates. A plurality of columnar sections formed at a predetermined interval between adjacent folded sections and a core layer formed between them are formed to function as a plate reinforcing material. Lightweight structural material based on composite materials.

2. In claim 1, The above first main plate, the above second main plate and the above reinforcing plate are made of metal or fiber reinforced plastic material, The above core layer is made of a non-metallic material. Lightweight structural material based on composite materials.

3. In claim 2, The above core layer is formed by injecting and curing a non-foaming polymer solution in a liquid state. Lightweight structural material based on composite materials.

4. In claim 1, A vertical reinforcement part formed by the above pillar part; and a horizontal reinforcement part formed by the second plate, the above reinforcement plate, and a core layer formed therebetween, are included to form a plate reinforcement structure. Lightweight structural material based on composite materials.

5. In claim 1, At least some of the above plurality of reinforcing plates are provided in the form of a tube with a hollow space formed inside. Lightweight structural material based on composite materials.

6. In claim 5, The above reinforcing plate has a polygonal or circular cross-sectional shape. Lightweight structural material based on composite materials.

7. In claim 5, Having a multi-shielding structure made of a composite material of metal and non-metal by the first main plate, the second main plate, the reinforcing plate and the core layer. Lightweight structural material based on composite materials.

8. In claim 5, The above plurality of reinforcing plates are arranged in at least two rows or at least two layers between the first main plate and the second main plate. Lightweight structural material based on composite materials.

9. In claim 5, Insulating material or fireproof material is inserted and placed in the internal space of the above reinforcing plate. Lightweight structural material based on composite materials.

10. In claim 1, At least one of insulation, fireproofing, piping and metal reinforcement is inserted and placed inside the core layer. Lightweight structural material based on composite materials.

11. In claim 1, Further comprising a finishing member that finishes at least one of the edge portion between the first main plate and the reinforcing plate and the edge portion between the second main plate and the reinforcing plate. Lightweight structural material based on composite materials.

12. In claim 1, The above first abacus is provided as a curved plate having a curvature. Lightweight structural material based on composite materials.

13. In claim 12, The above second plate is provided as a curved plate having a curvature. Lightweight structural material based on composite materials.

14. In claim 13, The ends of the first and second plates are connected to each other to form a streamlined shape that generates lifting force. Lightweight structural material based on composite materials.

15. First abacus made of metal; A second plate made of metal placed at a predetermined distance from the first plate; and Including a core layer of non-metallic material formed between the first main plate and the second main plate, The above core layer is formed to be thicker than other parts and includes an extension portion that protrudes to one side, The second plate is characterized in that it includes at least two bends to surround the extension. Cell guide structure for a container ship including lightweight structural materials based on composite materials.

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