Carbon fiber composite simply supported beam structure based on 3D printing

Abstract

The carbon fiber composite simply supported beam structure based on 3D printing comprises a top plate, a bottom plate, side plates, longitudinal partition plates and transverse partition plates, the top plate and the bottom plate are horizontally and oppositely arranged, and the upper end and the lower end of each longitudinal partition plate are connected with the top plate and the bottom plate respectively; according to the installation position of the longitudinal partition plate, the longitudinal partition plate is divided into three central webs, side webs on the two sides and a plurality of auxiliary webs, the top plate and the bottom plate are connected through the side plates on the two sides and the side webs on the two sides to form a closed box type cross section structure, the two ends of the transverse partition plate are connected with the side webs on the two sides, and porous structures are arranged on the side plates. The carbon fiber composite simply supported beam structure based on 3D printing has high mechanical strength and can meet the requirements of different working environments.

Description

Technical Field

[0001] The utility model discloses a large-span simply supported beam structure technology field, in particular to a carbon fiber composite simply supported beam structure based on 3D printing. Background Art

[0002] In recent years, new materials have been the focus of innovation in construction projects. Carbon fiber composite materials have a series of advantages such as high tensile strength, light weight, stable chemical properties, and excellent fatigue resistance. They have been used in construction projects at home and abroad as an ideal substitute for reinforced concrete.

[0003] Large-span simply supported beams are mainly divided into box beams and T beams. The interior of the box beam is hollow, with flanges on both sides of the upper part, similar to a box; it is usually made of steel and concrete, and is characterized by superior dynamic performance, good torsion resistance and bending resistance; it is classified according to the material, including two types, one is prestressed reinforced concrete box beam, and the other is steel box beam; according to the different processing methods, it can be divided into prefabricated box beams and cast-in-place box beams. The box beam prefabricated in an independent site can be erected after the completion of the foundation project with the bridge erection machine, which can speed up the progress of the project and save construction time. The box beam is an integral force system formed by welding the top plate, bottom plate, diaphragm and web plates. T beam refers to a beam with a T-shaped cross-section. The protruding parts on both sides are flanges, and the middle part is the beam rib (or web); because it is equivalent to digging out the concrete in the tensile zone of the box beam that does not work for bending strength, it has the same bending strength as the original rectangular beam, but it can save concrete, reduce the deadweight of the component, and improve the spanning capacity, but the torsion resistance is poor, and it is only suitable for straight bridge decks.

[0004] 3D printing technology is to use metal powder or plastic and other binding materials, light curing and paper lamination to print 2D images layer by layer in 3D stereoscopic form, also known as rapid prototyping technology. 3D printing technology has the following advantages: high design freedom, less waste and high efficiency.

[0005] In view of the shortcomings of the existing box girder structure, such as the complexity of the existing box girder structure, the difficulty in manufacturing prefabricated beams, the complex construction process, high cost, slow preparation, and inability to meet high-speed and accurate manufacturing, it is very meaningful to provide a 3D printed simply supported beam structure based on carbon fiber composite materials. Utility Model Content

[0006] In view of this, the utility model discloses a carbon fiber composite material simply supported beam structure based on 3D printing.

[0007] The technical solution provided by the utility model is specifically a carbon fiber composite simply supported beam structure based on 3D printing, comprising: a top plate, a bottom plate, a side plate, a longitudinal partition, and a transverse partition, wherein the top plate and the bottom plate are horizontally arranged opposite to each other, and the upper and lower ends of the longitudinal partition are respectively connected to the top plate and the bottom plate; according to the installation position of the longitudinal partition, it is divided into three central webs, side webs on both sides and a plurality of auxiliary webs, the side plates on both sides and the side webs on both sides connect the top plate and the bottom plate to form a closed box-type cross-sectional structure, the two ends of the transverse partition are connected to the side webs on both sides, and the side plates are provided with a porous structure.

[0008] Furthermore, the diaphragm is a solid-belly structure.

[0009] Furthermore, the thickness of the central web is greater than the thickness of the side webs and greater than the thickness of the auxiliary webs.

[0010] Furthermore, the porous structure on the side panel is symmetrically distributed, and the porous structure includes a five-hole structure unit located on both sides of the side panel, a single-hole structure unit, and an elliptical hole structure unit located in the middle of the side panel. The five-hole structure unit includes four symmetrically arranged equilateral triangle holes and a smooth diamond hole located in the center. The single-hole structure unit is a smooth vertical diamond hole, and every two groups of five-hole structure units are separated by a group of single-hole structure units; the elliptical hole structure unit includes two vertically arranged acute-angled triangle holes and two horizontally arranged elliptical holes, wherein the two acute-angled triangle holes are located between the two elliptical holes.

[0011] Furthermore, the elliptical hole structure units are provided with N groups, and the N groups of elliptical hole structure units are connected in series along the long direction of the bridge deck, and N is a natural number greater than or equal to 3.

[0012] Furthermore, the lateral stiffness of the simply supported beam structure is greater than the vertical stiffness.

[0013] The utility model provides a carbon fiber composite simply supported beam structure based on 3D printing, which has strong mechanical strength, can meet the requirements of different working environments, and improves the corrosion resistance, high temperature resistance, moisture and heat resistance, aging resistance, durability and other mechanical properties of the simply supported beam; the interior of the multi-box beam carbon fiber composite simply supported beam is composed of a box structure composed of a porous structure side plate and a thin and thick web plate, and the ratio of the elliptical structure and the thin and thick plates can be adjusted according to actual conditions to adapt to different loads and deformations.

[0014] It should be understood that the above general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present utility model, and together with the description, are used to explain the principles of the present utility model.

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of a carbon fiber composite material simply supported beam structure based on 3D printing provided in the disclosed embodiment of the utility model;

[0018] Figure 2 A schematic diagram of the internal planar structure of a carbon fiber composite material simply supported beam structure based on 3D printing provided in the disclosed embodiment of the utility model;

[0019] Figure 3 A three-point bending load-displacement curve of a carbon fiber composite simply supported beam structure based on 3D printing provided in the disclosed embodiment of the utility model. DETAILED DESCRIPTION

[0020] Here, exemplary embodiments will be described in detail, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the utility model. Instead, they are only examples of systems consistent with some aspects of the utility model as detailed in the attached claims.

[0021] like Figure 1 As shown, the present embodiment provides a carbon fiber composite simply supported beam structure based on 3D printing, comprising: a top plate 2, a bottom plate 3, a side plate 7, a longitudinal partition, and a transverse partition 8. The top plate 2 and the bottom plate 3 are arranged horizontally opposite to each other, and the upper and lower ends of the longitudinal partition are respectively connected to the top plate 2 and the bottom plate 3; according to the installation position of the longitudinal partition, it is divided into three central webs 6, side webs 4 on both sides and a number of auxiliary webs 5, the side plates 7 on both sides and the side webs 4 on both sides connect the top plate 2 and the bottom plate 3 to form a closed box-type cross-sectional structure, the two ends of the transverse partition 8 are connected to the side webs 4 on both sides, and the side plates 7 are provided with a porous structure.

[0022] The above-mentioned simply supported beam structure adopts a closed box-type cross-section, and the vertical and lateral stiffness are almost the same. The lateral stiffness is even greater than the vertical stiffness. Generally, there is no lateral bending phenomenon, and there is an internal mold, which has strong applicability. It can be used in straight lines and curves in the interval. Compared with the T-beam, the construction process is slightly more complicated. The T-beam structure is simple and easy to construct, but it has high requirements on construction quality. If the construction is not properly controlled, the beam body may bend sideways during the construction stage, and only the straight lines with the interval are used. At the same time, the box beam structure in this implementation scheme can use 3D printing technology to well solve the shortcomings of complex structure and cumbersome construction process.

[0023] The overall force-bearing system connected by 3D printing is evenly stressed and easy to process. The top plate directly bears the load, the top plate 2 and the bottom plate 3 are arranged horizontally and relatively, and the side plate 7 connects the top plate 2 and the bottom plate 3 to enhance the overall structural stability of the box and improve its anti-rollover and anti-torsion capabilities; that is, the setting of the top plate, bottom plate and central web, auxiliary web, side web and diaphragm enhances the overall strength and shear resistance of the simply supported beam;

[0024] The longitudinal diaphragm is divided into three central thickened webs 6, two thickened side webs 4 and several auxiliary webs, which connect the top plate and the bottom plate to form an integral cross section, mainly for shear resistance; the inter-span transverse diaphragm 8 is set as a solid web type to resist distortion under eccentric load and transverse bending deformation under load, maintain a stable cross-sectional shape, and transfer the bridge deck load to the longitudinal diaphragms on both sides. The central web and side web are set as thickened plates, which help to bear greater loads and work more stably; the auxiliary webs can be designed symmetrically according to the length of the simply supported beam;

[0025] The utility model only has one thickened span diaphragm, which is a solid-belly type, and can better resist distortion and lateral bending deformation under eccentric load.

[0026] The structure and quality of the side panels directly affect the service life of the box girder. In order to reduce the overall mass of the box girder and maintain a stable structure, the side panels adopt a porous structure, and the left and right parts are symmetrical.

[0027] Specifically, the porous structure on the side panel 7 is symmetrically distributed on the left and right, and the porous structure includes a five-hole structure unit 71 located on both sides of the side panel, a single-hole structure unit 72, and an elliptical hole structure unit 73 located in the middle of the side panel, the five-hole structure unit 71 includes four symmetrically arranged equilateral triangle holes and a smooth diamond hole located in the center, the single-hole structure unit 72 is a smooth vertical diamond hole, and every two groups of five-hole structure units 71 are separated by a group of single-hole structure units 72; the elliptical hole structure unit 73 includes two vertically arranged acute-angled triangle holes and two horizontally arranged elliptical holes, wherein the two acute-angled triangle holes are located between the two elliptical holes.

[0028] Among them, the elliptical hole structure as a weight-reducing hole can not only make the porous plate bear force evenly, but also achieve a significant weight reduction. The application of a reasonable elliptical hole structure can make the plate have good bending and compression resistance at the same time; the fundamental goal of the triangular hole is to make the force lines distributed inside the part coincide with the internal support beam as much as possible, that is, to make the internal support beam be in a two-force rod stress state as much as possible; the diamond hole refers to a weight-reducing hole with a shape similar to a quadrilateral. This type of weight-reducing hole is mostly used to reduce weight in the middle of multiple regular hole positions, or to remove as much material as possible in areas with less force.

[0029] Preferably, the five-hole structure unit of the composite porous structure plate comprises four triangular hole structures with a base length of 4.9 mm surrounding a smooth diamond hole structure with a longest diagonal of 6.148 mm. The five hole structures are separated by a single smooth vertical diamond hole structure with a longest diagonal of 6 mm.

[0030] The elliptical hole structure units are provided with N groups, and the N groups of elliptical hole structure units are connected in series along the long direction of the bridge deck, and N is a natural number greater than or equal to 3. The size of N is set according to actual needs.

[0031] A method for preparing a carbon fiber composite simply supported beam based on 3D printing, wherein the carbon fiber composite simply supported beam adopts a nylon carbon fiber PA-CF composite material, and the preparation method comprises the following steps:

[0032] (1) Prepare a 3D model in STL format using 3D modeling software according to the designed structure, and design the 3D printing path of the multi-box beam carbon fiber composite simply supported beam structure;

[0033] (2) preparing composite material 3D printing consumables and using a 3D printer to print a multi-box beam carbon fiber composite simply supported beam structure;

[0034] (3) During the 3D printing process, the samples were observed to adjust the 3D printing parameters, improve the printing quality and correct the printing parameters, and finally a controllable multi-box beam carbon fiber composite simply supported beam with excellent mechanical properties was obtained.

[0035] In step (1), the 3D modeling software used to design the 3D model is CATIA.

[0036] In step (2), the 3D printer is a G300 industrial-grade FDM 3D printer, and the diameter of the printer nozzle is 1 mm; the 3D printing consumables used are fiber-reinforced polymer-based composite material 3D printing consumables, and the diameter of this consumable is 1.75 mm.

[0037] In step (3), the 3D printing parameters are: printing platform temperature 50°C-100°C, printing nozzle temperature 200°C-280°C, preheating temperature 190°C-210°C, and preheating time 5 minutes.

[0038] The printing layer height of the multi-box beam carbon fiber composite material simply supported beam structure plate is 0.1 mm-0.3 mm, the printing filling rate is 100%, and the nozzle moving speed is 40 mm / s-70 mm / s.

[0039] The FDM 3D printing method effectively solves the stress concentration problem caused by traditional connection methods; 3D printing integrated rapid prototyping, a technology that constructs objects through "bottom-up" layered manufacturing and layer-by-layer stacking. The required porous structure can be manufactured quickly and accurately, greatly expanding the design freedom and meeting the social needs of low cost, fast manufacturing, and environmental protection.

[0040] The length, width and height of the 3D printed product of this embodiment were measured using a vernier caliper, with three points measured in each direction: the length was measured at three points at different positions at both ends, and the width and height were measured at the midpoint of the beam and 10 mm from the two end surfaces. The average deviation of the measurement results was 0.45%.

[0041] Use an electronic balance to weigh the mass m of the sample. Load the sample with three-point support until it breaks or deforms. The loading direction is perpendicular to the 250×30 plane with a span of 200mm. Record the load-displacement curve and the maximum load F of the sample.

[0042] See attached Figure 3 ; The measured mechanical parameters are: maximum bending force is 1665.79N; load-to-weight ratio is 21.27; weight is 78.8g, and the maximum deformation at 100N is 0.33mm;

[0043] In addition, subsequent experimental verifications have shown that under the same material conditions, the greater the thickness of the central web of this type of carbon fiber composite simply supported beam, the higher the overall strength, the greater the bearing capacity, and the smaller the deformation.

[0044] Under the same material conditions, the greater the thickness of the cross-span diaphragm between spans of this type of carbon fiber composite simply supported beam, the stronger the overall ability to resist eccentric loads and the smaller the lateral deformation.

[0045] It should be understood that the present invention is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A carbon fiber composite simply supported beam structure based on 3D printing, characterized in that: include: A top plate (2), a bottom plate (3), a side plate (7), a longitudinal partition, and a transverse partition (8), wherein the top plate (2) and the bottom plate (3) are arranged horizontally opposite to each other, and the upper and lower ends of the longitudinal partition are respectively connected to the top plate (2) and the bottom plate (3); according to the installation position of the longitudinal partition, it is divided into three central webs (6), side webs (4) on both sides, and a plurality of auxiliary webs (5); the side plates (7) on both sides and the side webs (4) on both sides connect the top plate (2) and the bottom plate (3) to form a closed box-type cross-sectional structure; the two ends of the transverse partition (8) are connected to the side webs (4) on both sides; and the side plates (7) are provided with a porous structure.

2. The carbon fiber composite simply supported beam structure based on 3D printing according to claim 1, characterized in that: The transverse partition (8) is a solid-belly structure.

3. The carbon fiber composite simply supported beam structure based on 3D printing according to claim 1, characterized in that: The thickness of the central web (6) is greater than the thickness of the side web (4) and greater than the thickness of the auxiliary web (5).

4. The carbon fiber composite simply supported beam structure based on 3D printing according to claim 1, characterized in that: The porous structure on the side plate (7) is symmetrically distributed, and the porous structure includes five-hole structural units (71) located on both sides of the side plate, a single-hole structural unit (72), and an elliptical hole structural unit (73) located in the middle of the side plate. The five-hole structural unit (71) includes four symmetrically arranged equilateral triangle holes and a smooth diamond hole located in the center. The single-hole structural unit (72) is a smooth vertical diamond hole. Every two groups of five-hole structural units (71) are separated by a group of single-hole structural units (72); the elliptical hole structural unit (73) includes two vertically arranged acute-angled triangle holes and two horizontally arranged elliptical holes, wherein the two acute-angled triangle holes are located between the two elliptical holes.

5. The carbon fiber composite simply supported beam structure based on 3D printing according to claim 4, characterized in that: The elliptical hole structure units are provided with N groups, and the N groups of elliptical hole structure units are connected in series along the long direction of the bridge deck, and N is a natural number greater than or equal to 3.

6. The carbon fiber composite simply supported beam structure based on 3D printing according to claim 4, characterized in that: The lateral stiffness of a simply supported beam structure is greater than its vertical stiffness.

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