Lightweight prestressed inflatable bag-cable panel supporting structure

Abstract

The invention provides a lightweight prestressed inflatable bag-cable panel supporting structure which is characterized in that a main structure framework is of a prism structure formed by rigidly connecting a plurality of truss rod pieces through a plurality of multi-way sheathing pieces, each multi-way sheathing piece comprises a plurality of sleeves and a fixing part, and the truss rod pieces are mounted in the matched sleeves; the panels are connected to the upper and lower surfaces of the main structure framework; the inhaul cable assembly comprises 2n stay cables, a vertical inhaul cable and two first connecting structures, the n stay cables are connected with the fixing parts of the n multi-way wrapping and sleeving parts on the upper surface of the main structure framework and the first connecting structures I correspondingly, and the other n stay cables are connected with the fixing parts of the n multi-way wrapping and sleeving parts on the lower surface of the main structure framework and the second connecting structures I correspondingly. The vertical inhaul cable is connected with the first and second connecting structures I; and the air bags are filled between the panels and the adjacent stay cables and are used for supporting the panels. According to the invention, the out-of-plane static and dynamic stiffness of a large-format panel in wing and rudder parts can be effectively improved, the structure is simple and efficient, and the lightweight design can be realized.

Description

Technical Field

[0001] This invention belongs to the field of aircraft technology, specifically relating to a lightweight prestressed inflatable bladder-cable panel support structure. Background Technology

[0002] Reusable aerospace vehicles represent the future direction of next-generation space transportation systems. The continuous and intense aerodynamic and noise loads experienced during atmospheric reentry place higher demands on the out-of-plane stiffness of large-area panels in the wings and rudder components. Improving out-of-plane stiffness and dynamic performance without increasing structural weight is a crucial issue in lightweight structural design. Summary of the Invention

[0003] This invention aims to solve one of the above-mentioned technical problems by providing a lightweight prestressed inflatable bladder-cable panel support structure. The panel support structure adopts an inflatable bladder-cable structure system, which effectively improves the out-of-plane static and dynamic stiffness of large-area panels in wing and rudder components. Its structure is simple and efficient, which helps to achieve lightweight design.

[0004] As one aspect of the present invention, a lightweight prestressed inflatable bladder-cable panel support structure is provided, comprising:

[0005] The main structural frame is a prism structure consisting of multiple truss members rigidly connected by multiple multi-port sleeves. The multi-port sleeves include several sleeves and fixing parts, and the truss members are installed in matching sleeves.

[0006] A panel, which is fixedly connected to the upper and lower surfaces of the main structural frame;

[0007] The cable assembly includes 2n inclined cables, one vertical cable, and two connecting structures I, where n is a positive integer greater than 1. One end of each of the n inclined cables is connected to the fixing part of n multi-pass package kits on the upper surface of the main structure frame, and the other end is connected to the first connecting structure I. One end of the remaining n inclined cables is connected to the fixing part of n multi-pass package kits on the lower surface of the main structure frame, and the other end is connected to the second connecting structure I. The two ends of the vertical cable are connected to the first and second connecting structures I, respectively.

[0008] An airbag is filled between the panel and the adjacent stay cable, and the airbag is inflated to support the panel.

[0009] Furthermore, the fixing part of the multi-pass package is a node with a channel, one end of the stay cable passes through the channel and is fixed to the node by a cable length adjustment structure, the cable length adjustment structure adjusts the prestress of the cable assembly; or the fixing part of the multi-pass package is a prefabricated irregular connecting plate, one end of the stay cable is fixed to the connecting plate;

[0010] The connection structure I includes a fixedly connected hemispherical shell and a cover plate. The hemispherical shell and the cover plate each have n hemispherical sockets for fixing the inclined cables. The end of the inclined cable extending into the hemispherical socket is spherical. The hemispherical shell has one spherical socket for fixing the vertical cable. The end of the vertical cable extending into the spherical socket is spherical.

[0011] Furthermore, the panel facing the cable assembly includes several ribs, the two ends of which are fixed to the main structural frame, and the airbag and the ribs transmit tensile and compressive support forces through a connecting rod;

[0012] The airbag is provided with a collar for connection to the cable-stayed bridge;

[0013] The airbag, collar, and connecting rod are made of metal material of a set thickness and are connected by welding; or the airbag, collar, and connecting rod are made of a single piece of molded composite material.

[0014] The main structural framework is a quadrangular prism structure, and n is 4.

[0015] As another aspect of the present invention, a lightweight prestressed inflatable bladder-cable panel support structure is provided, comprising:

[0016] The main structural frame is a quadrangular prism structure consisting of multiple truss members rigidly connected by multiple multi-port sleeves. The multi-port sleeves include several sleeves and fixing parts, and the truss members are installed in matching sleeves.

[0017] A panel, which is fixedly connected to the upper and lower surfaces of the main structural frame;

[0018] A cable assembly comprising multiple cables, with two cross cables arranged on each of the two opposite sides of the main structural frame, and the ends of the cables fixed to the fixing part of the multi-port kit;

[0019] An airbag is filled between the panel and the adjacent cross cables, and the airbag is inflated to support the panel.

[0020] Furthermore, multiple panel support structures extend and are arranged along a predetermined direction, with adjacent panel support structures sharing a common side surface, and the airbag passes through the gaps between the intersecting cables of the multiple panel support structures in a straight line.

[0021] The airbag is cylindrical, and multiple airbags with different radii are arranged between the panel and the adjacent cross cables.

[0022] Furthermore, the fixing part of the multi-port kit is a node with a channel, the end of the cable passes through the channel and is fixed to the node by a cable length adjustment structure, the cable length adjustment structure adjusts the prestress of the cable assembly; or the fixing part of the multi-port kit is a prefabricated irregular-shaped connecting plate, the end of the cable is fixed to the connecting plate;

[0023] The panel facing the cable assembly includes several ribs, the two ends of which are fixed to the main structural frame. The airbag and the ribs transmit tensile and compressive support forces through a connecting rod.

[0024] A separate ring is provided at the contact position between the airbag and the cable, and the ring is provided with a collar and a connecting rod that connect to the cable, the plate rib, and the connecting rod.

[0025] The ring, collar, and connecting rod are integrally formed structures.

[0026] Furthermore, the airbag includes a plurality of separating membranes, which are arranged in a cross or parallel pattern.

[0027] The connecting rod is a thin-walled circular tube. The connecting rod is connected to the plate rib through a connecting structure II. The connecting structure II includes a first through hole for the plate rib to pass through and a second through hole that is perpendicular to and communicates with the first through hole. The connecting rod is fixed in the second through hole by bolts.

[0028] Furthermore, the truss member includes an inner tube and a sleeve. The inner tube has several axially extending folds evenly arranged along its circumference, and the slope of the folds changes continuously. The sleeve completely covers the outside of the inner tube, or the sleeve is divided into several segments and evenly arranged along the axial direction of the inner tube on the outside of the inner tube. The inner tube is filled with gas at a set pressure.

[0029] Preferably, the inner tube is made of metal or metal-based composite material, the sleeve is made of fiber composite material winding, and a lubricating material is provided between the inner tube and the sleeve;

[0030] Alternatively, the truss members used to connect panels may have their compression areas locally thickened due to variable loads.

[0031] The truss members are welded to the multi-port package.

[0032] Furthermore, the panel includes an upper panel, a lower panel, and at least one layer of pressurized tubing located between the upper and lower panels;

[0033] Each layer of pressurized pipes is composed of several square-section pipes arranged together, with adjacent pipes sharing a side wall or maintaining a set gap between adjacent pipes.

[0034] Alternatively, each layer of pressurized pipes may be composed of several circular cross-section pipes arranged closely together;

[0035] The pipe is filled with gas at a set pressure.

[0036] Furthermore, the pressurized pipe includes multiple layers, the pipe has a square cross-section, an intermediate panel is provided between two adjacent layers of pressurized pipe, and the two adjacent layers of pressurized pipe are arranged in an orthogonal direction or arranged side by side vertically.

[0037] Alternatively, the pressurized pipe may comprise multiple layers, with each pipe having a circular cross-section; the upper and lower axes of adjacent layers of pressurized pipe may be aligned; or the upper and lower axes of adjacent layers of pressurized pipe may be staggered, with the axis of each pipe in the upper layer located on the tangent plane of the two pipes in the lower layer; or the axes of adjacent layers of pressurized pipe may be perpendicular.

[0038] As another aspect of the present invention, a wing or rudder main body structure is provided, which is composed of the above-mentioned inflatable bladder-cable panel support structure arranged continuously in a set direction.

[0039] The beneficial effects of this invention compared to the prior art are as follows:

[0040] (1) The support structure of this invention fully utilizes the prestress stiffness effect, achieving sufficient support stiffness in the cable assembly and support airbag through lightweight structure and high prestress level, resulting in a rational and efficient structural system. With this support structure, the panel can be designed to be thinner and lighter, saving on sheet material usage and meeting the requirements for lightweight panels. The stiffness of the support structure is easy to adjust; the structural support strength can be adjusted simply by adjusting the prestress level of the cables and the inflation amount of the airbag. Furthermore, different components do not interfere with each other, resulting in high overall structural reliability.

[0041] (2) The pressurized pleated inner tube-hoop combined truss member of the present invention realizes the decoupling of axial and circumferential prestresses under the state of air filling in the tube, the prestress distribution mode is more ideal, and the instability problem of the compressed member is effectively improved; the strength of each part of the material is efficiently utilized to meet the requirements of lightweight structure.

[0042] (3) The present invention adopts a strategy of locally thickening the truss chords. Compared with the overall thickening of the chord wall, it can effectively reduce the amount of material used and meet the requirements of lightweight structure. In addition, under the condition of a certain amount of material used, this scheme can support a larger out-of-plane load compared with conventional truss structure.

[0043] (4) The multi-port kit of the present invention has a simple design and can be adapted to various truss structure forms. The multi-port kit, together with the brazing connection method, can well meet the connection requirements of lightweight thin-walled members. The strength and reliability of the node connection can be guaranteed by the appropriate brazing area, and the structure is simple to install and adjust.

[0044] (5) The panel of the present invention adopts a pressurized pipe structure with a basically hollow interior, which can fully meet the requirements of lightweighting; the use of a pressurized hollow structure instead of a traditional solid structure not only reduces the structural weight, but also meets the structural rigidity requirements. Attached Figure Description

[0045] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0046] Figure 1 A schematic diagram of a multi-cell structure of a lightweight prestressed airbag-cable panel support structure provided for a specific embodiment of the present invention;

[0047] Figure 2 The following is a schematic diagram of a unit cell of an inflatable bladder-cable panel support structure provided for a specific embodiment of the present invention: (a) unit cell, (b) cable assembly, (c) node; (d) connection structure I; (e) airbag and panel, (f) airbag, (g) connection structure II;

[0048] Figure 3 A schematic diagram of another lightweight prestressed airbag-cable panel support structure multi-cell provided in a specific embodiment of the present invention;

[0049] Figure 4 A schematic diagram of another inflatable bladder-cable panel support structure unit cell provided for a specific embodiment of the present invention, (a) unit cell, (b) airbag and panel, (c) airbag;

[0050] Figure 5 A schematic diagram of a truss member structure is provided for a specific embodiment of the present invention, (a) stress analysis of the tube structure, (b) pressurized pleated inner tube-hoop combination truss member;

[0051] Figure 6 A schematic diagram of a truss member section with local thickening provided for a specific embodiment of the present invention, (a) stress analysis of the truss structure, (b) local thickening of the truss member section;

[0052] Figure 7 A schematic diagram of the connection between a multi-port kit and a truss member is provided for a specific embodiment of the present invention. (a) Front view, (b) Prefabricated irregular-shaped connecting plate, (c) Welding method of the multi-port kit and the truss member;

[0053] Figure 8A lightweight panel provided for a specific embodiment of the present invention includes (a) a single-layer pressurized pipe panel, (b) a single-layer pressurized pipe panel, (c) a double-layer pressurized pipe panel, and (d) a triple-layer pressurized pipe panel;

[0054] Figure 9 Another lightweight panel provided for a specific embodiment of the present invention includes: (a) a single-layer pressurized pipe panel; (b) the direction of pressurized pipe arrangement; (c) a double-layer pressurized pipe; and (d) a multi-layer pressurized pipe.

[0055] The above figures include the following reference numerals:

[0056] 1. Main structural frame; 101. Truss members; 102. Multi-port assembly; 103. Node; 104. Precast irregular-shaped connecting plate; 2. Panel; 201. Plate rib; 3. Cable assembly; 301. Stay cable; 302. Vertical cable; 303. Connection structure I; 304. Cable; 4. Airbag; 401. Collar; 402. Connecting rod; 403. Dividing diaphragm; 404. Connection structure II; 405. Hoop. Detailed Implementation

[0057] Specific embodiments of the present invention will now be described in detail. In the following description, specific details are set forth for purposes of explanation and not limitation, in order to aid in a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced in other embodiments departing from these specific details.

[0058] It should be noted that, in order to avoid obscuring the invention with unnecessary details, only the device structure and / or processing steps closely related to the solution of the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0059] Example 1

[0060] This embodiment provides a lightweight prestressed airbag-cable panel support structure as follows: Figure 1 , 2 As shown.

[0061] like Figure 1 The diagram shows the main structure of the wing and rudder, comprising several cells and panels laid on them, as well as panel support structures. Within each cell, the main structural frame 1 is a quadrangular prism structure rigidly connected by multiple truss members 101 via multiple multi-port assembly 102. The panels 2 are fixed to the upper and lower surfaces of the main structural frame 1 on all four sides. The multi-port assembly 102 includes several sleeves and fixing parts, with the truss members 101 installed in matching sleeves.

[0062] like Figure 2As shown in (a) and (b), the panel support structure consists of a composite high-strength cable assembly and an airbag 4. The cable assembly includes 2n inclined cables 301, one vertical cable 302, and two connecting structures I 303. In this embodiment, n is 4. One end of the inclined cable 301 is connected to the fixing part of the multi-port package 102, and the other end is connected to the vertical cable 302 through the connecting structure I 303.

[0063] like Figure 2 As shown in (c), one design of the fixing part of the multi-pass kit 102 is a spherical node 103 fixed to the multi-pass kit. The node 103 is provided with a channel, through which one end of the cable 301 can pass and be fixed to the node by an annular wedge.

[0064] like Figure 2 As shown in (d), one design of connecting structure I303 is a hemispherical hollow structure with a cover plate. The hemispherical shell and the cover plate each have four hemispherical sockets. These are tightened together with through bolts to secure one end of the stay cable. The end of the stay cable extending into the hemispherical socket is spherical. A spherical socket is located at the bottom of the hemispherical hollow structure to secure one end of the vertical stay cable. The end of the vertical stay cable extending into the spherical socket is also spherical. After all the stay cables are secured using the nodes and connecting structure I, the prestress of all the stay cables can be readjusted by removing the node annular wedges.

[0065] like Figure 2 As shown in (e, f), the airbag 4 and the stay cable 301 are connected by a collar 401. The airbag can be made of thin metal material, and the collar can also be made of metal material. The two can be connected by welding. The airbag and the collar can also be made of composite material using an integrated weaving method, which is beneficial for further weight reduction of the structure.

[0066] like Figure 2 As shown in (e, f), the airbag includes several dividing diaphragms. These diaphragms divide the airbag into multiple regions, and their tension and restraint during airbag inflation and deformation control the airbag's shape. Appropriate design of the diaphragm distribution and shape ensures that the areas of the airbag in contact with the structural panels and cables maintain a similar shape to the latter, facilitating interconnection and force transmission. Preferably, the dividing diaphragms are arranged in a cross or parallel pattern.

[0067] like Figure 2 As shown in (e, f), the side of panel 2 facing the cable assembly includes several ribs 201, with both ends of the ribs fixed to the main structural frame. A connecting rod 402 is provided between the airbag 4 and the panel ribs 201 to transmit tensile and compressive support forces. One design of the connecting rod 402 is as follows: Figure 2 As shown in (f), the connecting rod 402 and the airbag partition membrane 403 are designed as a single unit. The connecting rod 402 is a thin-walled circular tube structure with sufficient tensile strength and compressive stability, and it is connected to the plate rib 201 through connecting structure II 404. Figure 2 As shown in (g), the connecting structure II 404 includes a first through hole for the plate rib to pass through and a second through hole perpendicular to and communicating with the first through hole. The connecting rod is fixed in the second through hole by bolts. The plate ribs are arranged diagonally on the panel, and the connecting rods are evenly distributed on the plate ribs to evenly transmit tensile and compressive support forces.

[0068] This embodiment provides a lightweight prestressed airbag-cable panel support structure, the working principle of which is as follows:

[0069] The nodes are equipped with cable length adjustment structures, such as clamping anchorage nodes and annular wedges. After the cables are interconnected, pretension can be introduced into each cable by adjusting its length, forming a self-balancing load-bearing system supported by the nodes. With the cable cross-section remaining constant, increasing the pretension level in the cable system can significantly improve the deformation stiffness of the structural system. This achieves the effect of lightweighting the structure using high-strength materials.

[0070] An inflatable airbag is embedded between the panel and the aforementioned cable assembly as a force transmission link. The airbag is made of thin-walled, high-strength material, and its interior is divided into multiple regions by diaphragms. During the airbag's inflation and deformation, the traction limiting effect of the diaphragms controls the airbag's shape. Appropriate design of the diaphragm distribution and shape ensures that the areas of the airbag in contact with the structural panel and cables maintain a similar shape to the latter, facilitating interconnection and force transmission.

[0071] The airbag is shaped like a large-area spring, which can provide a large range of support and force transmission points for the structural panels. The higher the airbag inflation level, the greater its stiffness.

[0072] When the panel is initially installed, the connecting rods that connect the airbag and the panel ribs are not under stress or are under minimal stress; when the panel is subjected to external aerodynamic loads and deforms, the connecting rods can provide effective support, thereby suppressing the panel from flexing or deflecting inward or outward.

[0073] Example 2

[0074] like Figure 3 As shown, to reduce the difficulty of manufacturing the airbag, in this embodiment, instead of setting one airbag per cell, multiple cells are used to set a group of airbags. Each airbag is cylindrical in shape, and may not have a diaphragm inside or may only have several transverse diaphragms evenly arranged along the axial direction to simplify its manufacturing method.

[0075] like Figure 4As shown in (a), as the supporting structure for the airbag, a set of cross-composite high-strength tension cables 304 are installed on both sides of each main structural frame cell to provide uniform support for the airbag. Deformation stiffness is established in each cross-tension cable by introducing appropriate levels of prestress. At the contact point between the cylindrical airbag and the cross-tension cable, it is connected to the cable via a collar 401. At the contact point with the structural panel rib 201, a connecting rod 402 is installed to transmit tensile and compressive support forces. Multiple sets of cylindrical inflatable bladders can be installed in the extension direction of the main structural frame to make the panel more uniformly stressed, and the mutual support and force transmission between the bladders form a stable shape.

[0076] Compared to the scheme in Example 1, in this example, multiple cells only require one set of airbags and several cross cables for support, reducing the number of components and nodes, which facilitates further weight reduction of the structure.

[0077] Preferably, the cylindrical inflatable airbag installation method is as follows: Figure 4 As shown in (b) and (c), a separate ring 405 is provided at the contact point between the airbag and the cable. A collar 401 or a connecting rod 402 connected to the cable or panel is provided on the collar. The collar and connecting rod can be made by integrally weaving with the ring. During installation, the ring is placed on the airbag. After the airbag is inflated, it is tightened and connected to the ring. The load in all directions is transmitted through friction and clamping force.

[0078] Example 3

[0079] This embodiment provides a thin-walled pressurized pleated inner tube-hoop combination truss member.

[0080] Space truss structures are a highly efficient load-bearing structural system widely used in various fields of engineering. In aerospace engineering applications, lightweight structures are a constant requirement. In truss structures, member instability is one of the most significant factors limiting the full utilization of material strength, thus impacting lightweight design. Solving the instability problem of compression members without increasing structural weight is a key issue in lightweight truss design. To address this problem, this embodiment provides a thin-walled, pressurized, pleated inner tube-hoop composite truss member form, which fully utilizes the high-strength materials of both the inner and outer layers, effectively solving the instability problem of compression members and contributing to lightweight truss structure design.

[0081] like Figure 5 As shown in (a), for compression members in the form of circular steel tubes, pressurization can be used to counteract compressive stress and improve stability. However, the axial stress caused by pressurization is always half of the circumferential stress, which has no effect on counteracting the axial working stress. Instead, it first reaches the yield stress level of the metal material, causing the tube to fail. Therefore, this prestress distribution is not ideal for improving the buckling performance of the compression member.

[0082] To effectively utilize the axial prestress of the metal pressurized pipe fittings while avoiding the adverse effects of circumferential prestress, a design was developed. Figure 5 (b) shows the pleated inner tube-hoop combination component. The inner tube is a thin-walled tube with several axial pleats evenly arranged along its circumference. When the inner tube is subjected to circumferential stress, to ensure that this stress can be transferred to the circumferential hoop through the extension of the pleats, the pleat design should be smooth, i.e., the slope of the pleats should change continuously. Furthermore, the pleat height can be reasonably set according to the magnitude of the circumferential stress and the materials of the inner tube and the circumferential hoop.

[0083] To ensure airtightness, the inner tube should preferably be made of metal or metal-based composite material. A high-strength fiber composite of appropriate thickness is wound circumferentially, the thickness depending on the circumferential stress, the inner tube, and the circumferential clamping material, forming an outer clamping layer. Alternatively, the clamping layer can be made of multiple layers of high-strength fiber composite material wound axially along the inner tube, reducing manufacturing complexity. The spacing between the fiber tapes depends on the circumferential stress, the inner tube, and the circumferential clamping material. A suitable lubricating material can be placed between the inner tube and the outer clamping layer to reduce friction and allow for free deformation.

[0084] In the combined truss member structure proposed in this embodiment, when the inside is pressurized, the axial air pressure is directly borne by the inner tube, forming axial tensile stress within it; while the radial air pressure causes the cross section to tend to open circumferentially. Due to the presence of wrinkles, the circumferential opening deformation stiffness of the metal inner tube is extremely low, much smaller than the circumferential stiffness of the outer hoop layer. Thus, the circumferential tensile stress is only generated within the outer hoop layer, and the circumferential stress inside the inner tube is very small and can be ignored.

[0085] In this embodiment, the combined truss member structure achieves decoupling of axial and circumferential prestress. The axial load-bearing capacity of the member is generated by the inner tube, and the axial prestress can directly improve its compressive strength. Under internal pressure, the overall cross-section tends to be circular, which can suppress the instability of the thin-walled inner tube cross-section. More preferably, the inner tube is made of a metal matrix composite with longitudinally arranged fibers, and the sleeve is made of a high-strength composite with circumferentially arranged fibers, so that the material strength of both can be efficiently utilized.

[0086] Example 4

[0087] This embodiment provides a lightweight scheme for locally thickening the cross-section of truss chord members. In this embodiment, the truss chord members refer to the truss members used to connect the panels.

[0088] Increasing the height of a truss structure improves material strength and stiffness utilization efficiency during bending, leading to a lighter structural design. However, when truss height is limited, maximizing the effective structural height is a crucial issue in lightweight design. To address this, this embodiment provides a strategy of locally thickening truss chords, which helps increase the effective structural height in truss structures with limited external height. This measure is simple, efficient, and contributes to lightweight design.

[0089] Figure 6 (a) shows a schematic diagram of the force at the support point of a truss structure installed on the main body of the aircraft in the form of a cantilever beam. When the right end of the truss structure is subjected to a force F and the cantilever length of the truss is L, in order to maintain static equilibrium, the chord at the support must be able to withstand an axial force of R = FL / h, where h is the distance between the centroids of the chord sections at the two support points, which can be called the effective height of the structure.

[0090] To increase the load-bearing capacity of the truss structure, this embodiment adopts the following... Figure 6 (b) illustrates the local thickening treatment of the truss chord section, specifically the local thickening of the compression area caused by variable loads. This allows the centroid to shift outward while maintaining the overall stability of the truss chord, thereby increasing the effective height h of the structure. Consequently, without changing the overall structural dimensions and load-bearing conditions, the load-bearing capacity requirement R of the chord is reduced, thus reducing material usage and achieving a lightweight structure.

[0091] Specifically, if the chord section is rectangular, then the thickened area is... Figure 6 (b) shows the entire edge; the thickness of the thickening area depends on the total area of ​​the chord cross-section and the required centroidal displacement. If the chord cross-section is circular, the thickened area is... Figure 6 (b) shows the corresponding radian. The thickness of the thickening depends on the total area of ​​the chord cross section and the required outward displacement of the centroid.

[0092] Example 5

[0093] This embodiment provides a method for brazing truss members using a multi-port kit.

[0094] The continuous and intense aerodynamic and noise loads experienced by aerospace vehicles during atmospheric reentry place higher demands on the structural strength of wings and rudder components. As the primary load-bearing structure, maintaining lightweight design while improving structural strength is a crucial design challenge. To address this issue, this embodiment employs a multi-pass brazing connection system for the truss members, effectively enhancing the truss structural strength. This system is rational, efficient, and contributes to lightweight design.

[0095] like Figure 7As shown in (a), there are two main structural frame cells and the panels laid on them. In each cell, the four sides of the panel are fixed to the main structural frame by U-shaped members. The truss members are connected by sleeves on the multi-port assembly. To increase the strength of the main structural frame, each cell can also be equipped with two diagonal web members and two pairs of transverse connecting cross cables.

[0096] Truss members and multi-pass kits can be made of composite materials, such as... Figure 7 As shown in (c), the multiple interfaces of the multi-pass package are manufactured using an integrated molding method. To ensure the reliability of the welded connections of the thin-walled members, truss members are inserted into the multi-pass package, and the two are connected and fixed by brazing. Considering that the manufacturing difficulty of the integrated multi-pass package increases significantly with the increase of the number of channels and the number of channel intersections, cross cables are selected as the transverse connecting components of the main structural frame, and prefabricated irregular-shaped connecting plates adapted to the shape of the multi-pass package are used to connect the cable ends to the multi-pass package. One design scheme of the prefabricated irregular-shaped connecting plate 104 is as follows. Figure 7 As shown in (b), the connecting plate is brazed to the multi-pass package and the cable end. To increase the connection strength, the connecting plate is provided with an arc that matches the package, and the cable end is provided with a groove that matches the connecting plate.

[0097] Example 6

[0098] This embodiment provides a lightweight panel.

[0099] like Figure 8 As shown in (a), the panel includes an upper panel, a lower panel, and a pressurized pipe layer located between the upper and lower panels. The pressurized pipe layer is composed of several square-section pipe fittings arranged together, and the pipe fittings are filled with gas at a set pressure.

[0100] For the fabrication method of pressurized square cross-section sandwich panels, an integrated braiding molding technology is used for the upper and lower panels and the core pressurized tubing of non-metallic composite materials; and a 3D printing process is used for the upper and lower panels and the core pressurized tubing of metallic materials. The overall structure adopts an integrated molding process, which is simple to manufacture and does not require subsequent welding or bonding processes.

[0101] In this embodiment, the square hollow channel of the pressurized pipe is pressurized with a light gas, such as helium, reducing the panel's weight. Each component of the pressurized pipe in this embodiment is independent and not interconnected. Each component can be filled with gas at different pressures, which are set based on simulation results such as load conditions. This method improves the overall resistance to damage. If one or more components fail and leak gas, the other components remain unaffected and continue to bear the load.

[0102] In this embodiment, the pressurization pipes of the pressurized square cross-section sandwich panel can be designed with different interval thicknesses, such as... Figure 8As shown in (b), adjacent pipes in each layer of pressurized pipework share a common sidewall. The thickness of the sidewall can vary at different locations, or adjacent pipes in each layer of pressurized pipework can be arranged with a predetermined gap to further reduce the panel weight. A larger gap thickness increases the bending stiffness of the structure but also increases weight; a smaller gap thickness reduces weight but reduces load-bearing capacity. By designing different gap thicknesses, a balance can be found between load-bearing capacity and lightweighting.

[0103] In this embodiment, the pressurization pipes of the pressurized square cross-section sandwich panel can be designed as a double-layer orthogonal structure, such as... Figure 8 As shown in (c), the double-layer orthogonal structure adopts an integrated molding process, with the two layers sharing a common middle panel. This design enables the overall panel to exhibit orthogonal anisotropy, increasing stiffness in a specific direction and reducing structural deformation.

[0104] In this embodiment, the pressurization pipes of the pressurized square cross-section sandwich panel can be designed as a double-layer side-by-side structure, such as... Figure 8 As shown in (c), the double-layer side-by-side structure increases the porosity of the panel and the length of the heat transfer path between the upper and lower panels, which can improve the heat insulation effect. At the same time, it offers more options for the pressurization method, which can meet the needs of various working conditions.

[0105] In this embodiment, the pressurization pipes of the pressurized square cross-section sandwich panel can be designed as a multi-layer structure, such as... Figure 8 As shown in (d), the more layers a multi-layered structure has, the different pressures applied to each hole will cause variations in panel deformation and stiffness in different directions. This can be addressed by designing before manufacturing to meet diverse load requirements based on different operating conditions. However, more layers also increase the manufacturing process requirements, necessitating a balance between process and requirements. It should be noted that parallel charging ports can be installed at the same end of the charging pipes within the same layer to facilitate simultaneous injection of gas at the set pressure. For multi-layered charging pipes, the connection method of the charging ports can be adjusted according to the pipe orientation and pressure requirements to simplify the charging operation.

[0106] The pressurized square cross-section sandwich panel provided in this embodiment is applied to an aircraft. In order to simplify the manufacturing process, the sandwich panel can be made into modular components with different parameters. The external dimensions, number of pressurized pipe layers, pipe dimensions, etc. of the modular components are different. By splicing them together, a large-area panel is formed to meet the load requirements of different positions of the aircraft.

[0107] This embodiment provides a pressurized square-section sandwich panel that utilizes gas to transfer loads, ensuring uniform stress distribution throughout the structure. Furthermore, compared to existing aircraft panels, the square-section sandwich panel in this embodiment is essentially hollow internally, effectively meeting lightweight requirements. The use of a pressurized hollow structure instead of a traditional solid structure not only reduces structural weight but also meets structural stiffness requirements. In addition, designs with varying thicknesses and layer arrangements facilitate different functional applications, such as maintaining the panel's shape, actively changing its shape, and providing thermal insulation.

[0108] Example 7

[0109] This embodiment provides a lightweight panel.

[0110] like Figure 9 As shown in (a), the panel includes upper and lower panels and a middle sandwich tube. The sandwich tube is composed of several slender circular cross-section tubes arranged closely together. Several round tubes are connected side by side to form a plane, and the upper and lower panels are respectively attached to the upper and lower surfaces.

[0111] In this embodiment, the pressurized pipe sandwich panel can be formed using different methods as needed:

[0112] (1) The upper and lower panels and the sandwich pipe are made of non-metallic composite materials and are made of integrated braiding technology;

[0113] (2) The upper and lower panels and the sandwich tubes are made of metal materials and are printed using 3D printing technology;

[0114] (3) The upper and lower panels and the sandwich tube are made of non-metallic materials, and the sandwich tube is bonded and fixed to the upper and lower panels;

[0115] (4) The upper and lower panels and the sandwich tube are made of metal materials, and the sandwich tube is welded and fixed to the upper and lower panels;

[0116] (5) The upper and lower panels and the sandwich tube are made of flexible materials (such as polymer film materials, metal thin materials less than 0.1mm, etc.). The sandwich tube is welded and fixed to the upper and lower panels. The flexible material can deform according to the change of the tube inflation pressure. It can change the wing shape to adapt to the changes in the external load environment under different conditions (such as the aircraft take-off, level flight and descent phases).

[0117] In this embodiment, a sandwich pipe with a circular cross-section is used. Compared with a square cross-section, the manufacturing process is simpler and the cost is lower. The circular cross-section pipe can distribute the force evenly when subjected to pressure and has a higher pressure resistance. It is also easy to bend, twist and overlap.

[0118] In this embodiment, the sandwich-type pipe arrangement is a pressurized structure. Each pipe component is independent and not interconnected. Each component can be filled with gas at different pressures, with the inflation pressure set based on simulation results such as load conditions. This method improves the overall resistance to damage. If one or more components fail and leak air, the other components remain unaffected and continue to maintain their load-bearing capacity.

[0119] The pressurized structure consists of a circular cross-section sandwich tube filled with gas and upper and lower panels. The sandwich tube can be arranged in a single layer or multiple layers. The gas used is a light gas, such as helium, which reduces the mass of the panel. The inside of the sandwich tube can be filled with condensed liquid or gas. The specific heat capacity of the liquid is higher than that of the solid, ensuring that the panel heats up at a slower rate than the solid panel in high-temperature environments, resulting in better thermal insulation than the solid panel.

[0120] In this embodiment, the sandwich pipe structure can be designed as a multi-angle sandwich structure, such as... Figure 9 As shown in (b), the sandwich tube structure is designed with a multi-angle arrangement. This design enables the overall panel to exhibit anisotropic properties. By adjusting the arrangement angle of the sandwich tubes according to different loads, the stiffness in a specific direction can be increased, thereby reducing structural deformation.

[0121] In this embodiment, the sandwich pipe structure can be designed as a double-layer straight-pipe sandwich structure, such as... Figure 9 As shown in (c), two layers of straight pipes are arranged with their upper and lower axes aligned and connected by adhesive bonding. This structure has a simple manufacturing process and can significantly improve the in-plane shear strength of the sandwich structure.

[0122] In this embodiment, the sandwich pipe structure can be designed as a double-layer forked pipe sandwich structure, such as... Figure 9 As shown in (c), the upper axes of the double-layer forked pipe sandwich structure are arranged in an interlaced manner. The axis of each pipe in the upper layer is displaced on the tangential plane of the two pipes in the lower layer. This structure can reduce the gap, make full use of the material, and reduce the overall structural thickness.

[0123] In this embodiment, the sandwich pipe structure can be designed as a double-layer orthogonal pipe sandwich structure, such as... Figure 9 As shown in (c), the two layers of sandwich pipes in the double-layer orthogonal structure are axially perpendicular and arranged in parallel relative to each other. The orthogonal structure provides stiffness to the structure in two orthogonal directions and can maintain the shape of the panel when subjected to lateral loads.

[0124] In this embodiment, the sandwich pipe structure can be designed as a multi-level sandwich pipe structure, such as... Figure 9 As shown in (d), the number of structural layers and the diameter of the pipes can be determined according to the load requirements. In a multi-layered structure, the pipe diameter of each layer can be different. This method allows for flexible adjustment of the structural design according to different working conditions, making it highly adaptable.

[0125] It should be noted that pressurization ports can be connected in parallel at the same end of the pressurization pipes on the same layer, so as to facilitate the simultaneous filling of gas at the set pressure; for multi-layer pressurization pipes, the connection method of the pressurization ports can be adjusted according to the pipe direction and pressure requirements to simplify the pressurization operation.

[0126] The panel in this embodiment adopts a modular design, including a single-layer pressurized pipe sandwich panel module, a double-layer pressurized pipe sandwich panel module, and a multi-layer pressurized pipe sandwich panel module. The structural parameters of each panel module are different, and the appropriate panel module is determined according to the surface load distribution of the aircraft.

[0127] This embodiment provides a pressurized pipe sandwich panel that utilizes gas to transfer loads, ensuring uniform stress distribution throughout the structure. Furthermore, compared to existing aircraft panels, the sandwich panel in this embodiment is essentially hollow, effectively meeting lightweight requirements. Replacing the traditional solid structure with a pressurized pipe sandwich panel not only reduces structural weight but also meets structural rigidity requirements. Additionally, different sandwich arrangement designs facilitate shape shaping and maintenance.

[0128] The features described and / or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or in combination with or in lieu of features in other embodiments.

[0129] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, components, or combinations thereof.

[0130] Many features and advantages of these embodiments are apparent from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since many modifications and alterations will readily occur to those skilled in the art, the embodiments of the invention are not intended to be limited to the precise structures and operations illustrated and described, but rather to encompass all suitable modifications and equivalents falling within their scope.

[0131] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0132] The parts of this invention not described in detail are techniques known to those skilled in the art.

Claims

1. A lightweight prestressed inflatable bladder-cable panel support structure, characterized in that, include: The main structural frame is a prism structure consisting of multiple truss members rigidly connected by multiple multi-port sleeves. The multi-port sleeves include several sleeves and fixing parts, and the truss members are installed in matching sleeves. A panel, which is fixedly connected to the upper and lower surfaces of the main structural frame; The cable assembly includes 2n inclined cables, one vertical cable, and two connecting structures I, where n is a positive integer greater than 1. One end of each of the n inclined cables is connected to the fixing part of n multi-pass package kits on the upper surface of the main structure frame, and the other end is connected to the first connecting structure I. One end of the remaining n inclined cables is connected to the fixing part of n multi-pass package kits on the lower surface of the main structure frame, and the other end is connected to the second connecting structure I. The two ends of the vertical cable are connected to the first and second connecting structures I, respectively. An airbag is filled between the panel and the adjacent stay cable, and the airbag is inflated to support the panel.

2. The structure according to claim 1, characterized in that, The fixing part of the multi-pass package is a node with a channel. One end of the stay cable passes through the channel and is fixed to the node by a cable length adjustment structure. The cable length adjustment structure adjusts the prestress of the cable assembly; or the fixing part of the multi-pass package is a connecting plate, and one end of the stay cable is fixed to the connecting plate. The connection structure I includes a fixedly connected hemispherical shell and a cover plate. The hemispherical shell and the cover plate each have n hemispherical sockets for fixing the inclined cables. The end of the inclined cable extending into the hemispherical socket is spherical. The hemispherical shell has one spherical socket for fixing the vertical cable. The end of the vertical cable extending into the spherical socket is spherical.

3. The structure according to claim 1, characterized in that, The panel facing the cable assembly includes several ribs, the two ends of which are fixed to the main structural frame. The airbag and the ribs transmit tensile and compressive support forces through a connecting rod. The airbag is provided with a collar for connection to the cable-stayed bridge; The airbag, collar, and connecting rod are made of metal material of a set thickness and are connected by welding; or the airbag, collar, and connecting rod are made of a single piece of molded composite material. The main structural framework is a quadrangular prism structure, and n is 4.

4. A lightweight prestressed inflatable bladder-cable panel support structure, characterized in that, include: The main structural frame is a quadrangular prism structure consisting of multiple truss members rigidly connected by multiple multi-port sleeves. The multi-port sleeves include several sleeves and fixing parts, and the truss members are installed in matching sleeves. A panel, which is fixedly connected to the upper and lower surfaces of the main structural frame; A cable assembly comprising four cables, with two cross cables arranged on each of the two opposite sides of the main structural frame, and the ends of the cables fixed to the fixing part of the multi-port kit; An airbag is filled between the panel and the adjacent cross cables, and the airbag is inflated to support the panel.

5. The structure according to claim 4, characterized in that, Multiple panel support structures extend and are arranged along a predetermined direction, with adjacent panel support structures sharing a common side surface, and the airbag passing through the gaps between the multiple panel support structures in a straight line. The airbag is cylindrical, and multiple airbags with different radii are arranged between the panel and the adjacent cross cables.

6. The structure according to claim 4, characterized in that, The fixing part of the multi-pass package is a node with a channel, the end of the cable passes through the channel and is fixed to the node by a cable length adjustment structure, the cable length adjustment structure adjusts the prestress of the cable assembly; or the fixing part of the multi-pass package is a connecting plate, the end of the cable is fixed to the connecting plate; The panel facing the cable assembly includes several ribs, the two ends of which are fixed to the main structural frame. The airbag and the ribs transmit tensile and compressive support forces through a connecting rod. A separate ring is provided at the contact position between the airbag and the cable, and a collar and a connecting rod are provided on the ring to connect with the cable and the plate rib; The ring, collar, and connecting rod are integrally formed structures.

7. The structure according to claim 3 or 6, characterized in that, The airbag includes several partition membranes, which are arranged in a cross or parallel pattern. The connecting rod is a thin-walled circular tube. The connecting rod is connected to the plate rib through a connecting structure II. The connecting structure II includes a first through hole for the plate rib to pass through and a second through hole that is perpendicular to and communicates with the first through hole. The connecting rod is fixed in the second through hole.

8. The structure according to any one of claims 1 to 7, characterized in that, The truss member includes an inner tube and a sleeve. The inner tube has several axially extending folds evenly arranged along its circumference, and the slope of the folds changes continuously. The sleeve completely covers the outside of the inner tube, or the sleeve is divided into several segments and evenly arranged along the axial direction of the inner tube on the outside of the inner tube. The inner tube is filled with gas at a set pressure. Preferably, the inner tube is made of metal or metal-based composite material, the sleeve is made of fiber composite material wound together, and a lubricating material is provided between the inner tube and the sleeve. Alternatively, the truss members used to connect panels may have their compression areas locally thickened due to variable loads. The truss members are welded to the multi-port package.

9. The structure according to any one of claims 1 to 7, characterized in that, The panel includes an upper panel, a lower panel, and at least one layer of pressurized pipe located between the upper and lower panels; Each layer of pressurized pipes is composed of several square-section pipes arranged together, with adjacent pipes sharing a side wall or maintaining a set gap between adjacent pipes. Alternatively, each layer of pressurized pipes may be composed of several circular cross-section pipes arranged closely together; The pipe is filled with gas at a set pressure.

10. A wing or rudder main body structure, characterized in that, The inflatable bladder-cable panel support structure described in any one of claims 1 to 9 is continuously arranged in a set direction.

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