A foldable assembled truss protection structure based on kresling configuration, design method and use method

Abstract

The present application relates to a kind of Kresling configuration-based easily foldable combined truss protective structure, design method and use method, including upper panel and lower panel, Kresling configuration-based foldable truss structure core layer is clamped between upper panel and lower panel, and node connection is passed between surface layer and core layer.Upper panel and lower panel have good anti-penetration and anti-blast performance;Core layer realizes the convenient folding and unfolding of combined structure, is convenient to store and transport after folding, and has excellent normal compression bearing performance after unfolding;Three are realized by wave impedance mismatch, and high-efficiency blast isolation and anti-blast are realized.Theoretical calculation, finite element optimization and test verification are combined to realize the design of different protective performance foldable combined truss protective structure.The present application can make up the shortcomings of traditional protective structure, such as single function, large size, large self-weight, inconvenient storage and transportation, and has good application prospect in military and civilian impact and explosion protection field.

Description

TECHNICAL FIELD

[0001] The present application relates to a Kresling configuration-based foldable and deployable combined truss protective structure, a design method and a use method, and belongs to the field of foldable superstructures. BACKGROUND

[0002] Superstructures are innovations relative to traditional rods, columns, beams, plates and other structures, and can meet the requirements for changing structural characteristics, deformation characteristics and folding and shrinking functions, and are particularly suitable for places with difficult environments and special use conditions. At present, superstructures play an increasingly important role in various fields such as aerospace, precision medicine, special machinery manufacturing, architectural design, and protective engineering, and show the ability to solve major needs.

[0003] In the impact and explosion disaster prevention and mitigation engineering, in order to prevent and reduce the impact damage of explosion shock wave and explosion fragments on personnel, equipment and buildings, one or more protective barriers are usually set to prevent the explosion effect from directly acting on the target. For example, traditional protective methods include building a layer of reinforced concrete blast wall outside the target, piling up sandbags or sand soil cage blast wall, water explosion isolation wall, external steel plate, high-performance fiber plate or sandwich structure method. However, these traditional methods have some shortcomings to varying degrees. For example, the concrete, sand body and water body type blast-resistant structures not only have large weight and volume, low construction efficiency, but also require mechanized construction and are severely dependent on local engineering resources. The external steel plate has small volume but large weight. The high-performance fiber plate has small volume and light weight, but the blast isolation and wave absorption efficiency is limited. The sandwich type core structure can achieve high-efficiency blast isolation by wave impedance mismatch, but it has large volume and is not convenient to store and transport after prefabrication. Therefore, in view of the existing deficiencies, it is necessary to upgrade the existing blast-resistant protective structures accordingly, and to further realize the design and application of new blast-resistant superstructures with light weight, small volume, foldable, high-efficiency blast isolation and impact penetration resistance, prefabrication and mobile deployment and construction, and no local resource constraints on the basis of absorbing the advantages of traditional structures. SUMMARY

[0004] The present application provides a Kresling configuration-based foldable and deployable combined truss protective structure, a design method and a use method, which realizes efficient blast resistance and space saving during transportation and storage under the premise of meeting the foldable characteristics.

[0005] The technical solution adopted by the present application to solve its technical problems is:

[0006] A Kresling configuration-based foldable and deployable combined truss protective structure, comprising an upper panel and a lower panel, and a foldable truss structure core layer based on a Kresling configuration is arranged between the upper panel and the lower panel;

[0007] The upper panel or the lower panel is selected from a polygon or a circle;

[0008] The foldable truss structure core layer comprises a plurality of type I members and type II members, both ends of the type I member are connected to the upper panel and the lower panel respectively, and both ends of the type II member are also connected to the upper panel and the lower panel respectively;

[0009] One type I member and one type II member are arranged at each connection point position of the panel surface of the upper panel or the lower panel;

[0010] When the combined truss protection structure is under load, the included angle between the type I member and the lower panel is less than 90°, and the included angle between the type II member and the lower panel is also less than 90°;

[0011] As a further preferred embodiment of the present application, one type I member and one type II member are set as a group of structures, one end of the type I member in each group of structures is connected to the same intersection point position of the upper panel as one end of the type II member in the adjacent group of structures, the other end of the type I member in each group of structures is connected to the same intersection point position of the lower panel as the other end of the type II member in the group of structures, and one end of the type II member in each group of structures is connected to the same intersection point position of the upper panel as one end of the type I member in the adjacent group of structures;

[0012] As a further preferred embodiment of the present application, the type I member comprises a type I member outer hollow compression-resistant circular tube and a type I member inner spring, the type I member inner spring is arranged in the type I member outer hollow compression-resistant circular tube, and both ends of the type I member inner spring extending out of the type I member outer hollow compression-resistant circular tube are connected to type I member connection nodes respectively;

[0013] The type I member connection node is used for connecting the type I member and the upper panel or the lower panel;

[0014] As a further preferred embodiment of the present application, the type II member comprises a type II cylindrical member main body, and type II member connection nodes are arranged at both ends of the type II cylindrical member main body respectively;

[0015] The type II member connection node is used for connecting the type II member and the upper panel or the lower panel;

[0016] As a further preferred embodiment of the present application, the upper panel or the lower panel is made of high-performance FRP material;

[0017] The type I member or the type II member is made of high-performance FRP material;

[0018] As a further preferred embodiment of the present application, in the upper panel or the lower panel, the aforementioned high-performance FRP material is an ultra-high molecular weight polyethylene composite material hot-pressed laminated plate;

[0019] In the Type I or Type II rod, the high-performance FRP material is CFRP or GFRP or BFRP or a high-performance aluminum alloy;

[0020] As a further preferred embodiment of the present application, the upper panel and the lower panel are encapsulated with a polyurea coating;

[0021] As a further preferred embodiment of the present application, the surface of the upper panel facing the outside and the surface of the lower panel facing the outside are sprayed with an electromagnetic absorption coating or an electromagnetic absorption structure layer is added;

[0022] A design method of a foldable and deployable combined truss protective structure based on Kresling configuration, specifically comprising the following steps:

[0023] Step S1: Numerical calculation and checking of the foldability of the foldable and deployable combined truss protective structure to be designed;

[0024] Step S2: Calculation and simulation of real penetration and explosion cases by using material penetration resistance and structure blast resistance theoretical calculation formula and combining with finite element modeling method, to calculate the material type and penetration resistance thickness of the upper panel and the lower panel, and to confirm the protective performance of the upper panel and the lower panel;

[0025] Step S3: Establishing an anti-penetration and blast calculation model of the foldable and deployable combined truss protective structure by using finite element modeling method, determining the truss structure form, material selection and rod size, and according to the deformation and damage degree, energy absorption size and blast isolation and wave absorption performance of the foldable and deployable combined truss protective structure under the action of explosion impact load, determining the anti-penetration and blast performance of the foldable and deployable combined truss protective structure;

[0026] Step S4: Protective performance test verification of the foldable and deployable combined truss protective structure model after numerical calculation and optimization design, verifying the bullet penetration resistance performance, deformation and damage process and degree, energy absorption characteristics and blast isolation and wave absorption performance of the combined structure, and finally determining the combined structure form meeting the protective index;

[0027] Step S5: Preparing the upper panel, the lower panel, the Type I rod and the Type II rod according to the combined structure form and parameters after optimization design;

[0028] Step S6: The two ends of each Type I rod and Type II rod are connected to the upper panel and the lower panel in the combined structure respectively, so as to limit the linear displacement of the Type I rod and the Type II rod, and form a stable and reliable connection node;

[0029] A use method of a foldable and deployable combined truss protective structure based on Kresling configuration, when the foldable and deployable combined truss protective structure is in a deployed and stable state, it has a bearing capacity in the normal direction, and the bearing capacity is matched with the size, angle and material of the foldable and deployable combined truss protective structure.

[0030] When the foldable and deployable combined truss protective structure is transformed from the unfolded and loaded state to the folded state, the normal direction of the upper plane to the upper plane is the tensile direction of the I-shaped rod, the I-shaped rod is rotated until the plane polygon of the upper plane and the plane polygon of the lower plane are initially parallel to each other, and after the mutual parallelism is reached, the upper panel is compressed in the normal direction of the upper panel;

[0031] When the foldable and deployable combined truss protective structure is transformed from the folded state to the unfolded and loaded state, the upper panel is directly stretched or stretched and rotated until the combined structure reaches the stable state after unfolding.

[0032] Through the above technical scheme, compared with the prior art, the present application has the following beneficial effects:

[0033] 1. The foldable and deployable combined truss protective structure based on the Kresling configuration provided by the present application has a foldable function, is convenient for manual deployment, is in a stable state after deployment and has strong normal compression bearing performance; the convenient folding can be realized by the mode of reverse stretching and then compression, and the storage and transportation space can be reduced after the combined structure is folded and unfolded;

[0034] 2. In the foldable and deployable combined truss protective structure based on the Kresling configuration provided by the present application, the upper panel and the lower panel have a certain thickness, so that they have penetration resistance and explosion protection performance; when the upper panel and the lower panel are preferred light and high-strength FRP materials such as UHMWPE hot-pressed laminated plates, the lightweight advantage of the combined structure is more obvious compared with traditional protective structures;

[0035] 3. The foldable and deployable combined truss protective structure based on the Kresling configuration provided by the present application adopts a porous truss sandwich layer based on the Kresling configuration, the truss part and the panel form a wave impedance mismatch, which is beneficial to blocking the transmission of explosion shock waves and has good explosion isolation and explosion resistance;

[0036] 4. In the foldable and deployable combined truss protective structure based on the Kresling configuration provided by the present application, the upper panel and the lower panel are packaged by spraying polyurea, which effectively improves the protective performance and multiple use performance of the combined structure, improves the corrosion and aging resistance and fire resistance, and reduces the degree of structural impact and explosion damage;

[0037] 5. In the foldable and deployable combined truss protective structure based on the Kresling configuration provided by the present application, the outermost layer of the upper panel and the lower panel adopts a sprayed electromagnetic absorption coating or an added electromagnetic absorption structure layer, which effectively improves the camouflage and anti-detection capability of the combined structure. BRIEF DESCRIPTION OF DRAWINGS

[0038] The present application will be further described below in combination with the drawings and examples.

[0039] Figure 1 is a schematic view of the preferred embodiment of the present application in the unfolded carrying state;

[0040] Figure 2 is a perspective view of the preferred embodiment of the present application in the unfolded carrying state;

[0041] Figure 3 is a schematic view of the preferred embodiment of the present application in the half-folded state;

[0042] Figures 4a-4b is a schematic view of the core structure of the foldable truss structure without the upper panel and the lower panel according to the preferred embodiment of the present application;

[0043] Figures 5a-5d is a schematic view of the multi-angle split structure of the I-type rod according to the preferred embodiment of the present application;

[0044] Figures 6a-6d is a schematic view of the multi-angle split structure of the II-type rod according to the preferred embodiment of the present application;

[0045] Figure 7 is a schematic view of the upper panel or the lower panel structure with a sprayed polyurea coating according to the preferred embodiment of the present application;

[0046] Figure 8 is a schematic view of the upper panel or the lower panel structure with a sprayed electromagnetic absorption camouflage coating or an added electromagnetic absorption structure layer according to the preferred embodiment of the present application;

[0047] Figure 9 is a finite element model of the easy-foldable combined truss protective structure based on the Kresling configuration established in the specific case according to the preferred embodiment of the present application;

[0048] Figures 10a-10d is a strain comparison chart of the rods in the folding process of the easy-foldable combined truss protective structure based on the Kresling configuration and the traditional Kresling truss structure in the specific case according to the preferred embodiment of the present application;

[0049] Figure 11 is a comparison chart of the work done by external forces in the folding process of the easy-foldable combined truss protective structure based on the Kresling configuration and the traditional Kresling truss structure in the specific case according to the preferred embodiment of the present application.

[0050] In the figure: 1 is the upper panel, 2 is the lower panel, 3 is the I-type rod, 4 is the II-type rod, 5 is the polyurea coating, 6 is the electromagnetic absorption coating or electromagnetic absorption structure layer on the outer side of the panel, 301 is the internal spring of the I-type rod, 302 is the external hollow compression-resistant circular tube of the I-type rod, 303 is the connection node of the I-type rod, 401 is the main body of the II-type cylindrical rod, and 402 is the connection node of the II-type rod. Detailed Implementation

[0051] The present invention will now be described in further detail with reference to the accompanying drawings. In the description of this application, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the scope of protection of the present invention.

[0052] As described in the background section, current blast-resistant protective structures suffer from various problems, such as being bulky and large, having poor mobility, low protection efficiency, and being highly dependent on resources. Therefore, as an upgrade and modification, this application aims to provide a structure with the following characteristics: lightweight, foldable and small in size, highly efficient explosion-proof and impact-resistant, prefabricated and mobile for deployment, easy to assemble, and not constrained by local resources. It is a new type of bulletproof and blast-resistant superstructure design and application.

[0053] To achieve the above-mentioned technical effects, this application first designs a foldable structure. When folded, the wave impedance mismatch between the surface layer and the porous core layer is used to achieve high-efficiency explosion resistance. During transportation and storage, since the structure is foldable, it can be folded and stored to save space significantly.

[0054] like Figure 1 The diagram shown is an overall structural schematic of this application, including an upper panel 1 and a lower panel 2. A foldable truss structure core layer based on the Kresling configuration is sandwiched between the upper and lower panels. This design adopts a "hard-soft-hard" sandwich structure. The panel and the core layer can achieve efficient explosion-proof and explosion-proof performance through wave impedance mismatch.

[0055] The most distinctive feature of this application is the central, Kresling-based, foldable truss core layer, which comprises several Type I members 3 and Type II members 4. The two ends of the Type I members are connected to the top and bottom plates, respectively; similarly, the two ends of the Type II members are also connected to the top and bottom plates. The arrangement of the Type I and Type II members is such that one Type I member and one Type II member are simultaneously placed at each connection point on the surface of either the top or bottom panel. When the composite truss protective structure is under load, the Type I members are self-expanding structures that can switch between compression and tension, forming an inclined state. However, to ensure load-bearing capacity, the angle between either the Type I or Type II member and the bottom panel is less than 90°. Figure 2The figure is the top view of the folded truss structure core layer, after the folded truss structure core layer is unfolded, a group of truss members is distributed on each side, and each group of truss members is composed of one I-shaped member and one II-shaped member. Figure 3 The figure is the schematic diagram of the folded truss structure core layer, through the self-stretching capacity of the I-shaped member, the I-shaped member is tilted in a certain direction, and the II-shaped member is tilted, namely, the upper panel, the lower panel and the II-shaped member do not have obvious deformation, the spring in the I-shaped member is stretched and deformed, and the folding and unfolding of the combined structure is realized.

[0056] Figures 4a-4b The figure is the simplified folded truss structure core layer structure, namely, the upper panel and the lower panel are not included, one I-shaped member and one II-shaped member are set as one group of structures, when the upper panel or the lower panel is a polygon in the plane, the number of the I-shaped members and the II-shaped members is recommended to be consistent with the number of the side lengths, one end of the I-shaped member in each group of structures and one end of the II-shaped member in the adjacent group of structures are simultaneously connected to the same intersection point position of the upper panel, the other end of the I-shaped member in each group of structures and the other end of the II-shaped member in the group of structures are simultaneously connected to the same intersection point position of the lower panel, and one end of the II-shaped member in each group of structures and one end of the I-shaped member in the adjacent group of structures are simultaneously connected to the same intersection point position of the upper panel.

[0057] Here, the cross-sectional shape of the I-shaped member or the II-shaped member can be any polygon or a circle, and the geometric parameters, the number and the arrangement density of the members are designed according to actual requirements.

[0058] The specific structure of the I-shaped member or the II-shaped member is shown in the following figures. Figures 5a-5d The figure is the specific structure schematic diagram of the I-shaped member, including the I-shaped member external hollow compression-resistant circular tube 302 and the I-shaped member internal spring 301, the I-shaped member internal spring is arranged in the I-shaped member external hollow compression-resistant circular tube, and the two ends of the I-shaped member internal spring that are out of the I-shaped member external hollow compression-resistant circular tube are respectively connected to the I-shaped member connecting node 303; the I-shaped member connecting node is used for connecting the I-shaped member and the upper panel or the lower panel. The I-shaped member internal spring is tightly connected to the I-shaped member connecting node, and the I-shaped member external hollow compression-resistant circular tube is separated from the I-shaped member connecting node, the I-shaped member internal spring is used for bearing the tensile load transmitted by the I-shaped member connecting node, and the I-shaped member external hollow compression-resistant circular tube is used for bearing the compressive load transmitted by the I-shaped member connecting node. Figures 6a-6d The figure is the specific structure schematic diagram of the II-shaped member, including the II-shaped cylindrical member main body 401, and the two ends of the II-shaped cylindrical member main body are respectively connected to the II-shaped member connecting node 402; the II-shaped cylindrical member main body is used for resisting tension, compression and providing bearing capacity, and the II-shaped member connecting node is used for connecting the II-shaped member and the upper panel or the lower panel. The aforementioned I-shaped member connecting node and the II-shaped member connecting node can form a stable and reliable relationship between the I-shaped member and the II-shaped member and the upper panel or the lower panel.

[0059] The angle between the I-shaped rod and the lower panel should be less than 90° to achieve the easy folding property of the combined structure; the angle between the II-shaped rod and the lower panel should be less than 90° to achieve the good compression bearing performance of the combined structure after unfolding. That is, the core layer structure is hollow inside, light in weight, strong in deformation ability and design, and especially the open topological structure provides an improvement space for the optimization design of the bearing performance and explosion-proof performance of the combined structure.

[0060] After considering the design of the related structure, the material used by the structure should also be considered. First, the upper panel and the lower panel, considering the light weight, high strength and convenience of the combined structure, high-performance FRP materials such as ultra-high molecular weight polyethylene composite hot-pressed laminated plate (UHMWPE fiber laminated plate) are recommended, which not only has extremely low weight, but also has excellent bulletproof and explosion-proof performance. Regarding the I-shaped rod or the II-shaped rod, considering the light weight, high strength and convenience of the combined structure, high-performance FRP materials such as CFRP or GFRP or BFRP or high-performance aluminum alloy are recommended, and the upper panel and the lower panel are encapsulated by polyurea coating 5, wherein the I-shaped rod inside the I-shaped rod is recommended to use a metal material with high elastic limit, high fatigue limit, high impact toughness and good heat treatment performance.

[0061] Figure 7 As shown, the upper panel and the lower panel of the combined structure are encapsulated by spraying polyurea, which further improves the anti-penetration and explosion-proof performance of the upper panel and the lower panel, effectively improves the protection performance and multiple use performance of the combined structure, improves the corrosion and aging resistance and fire resistance, and reduces the deformation damage. Figure 8 As shown, the outermost layer of the upper panel and the lower panel of the combined structure is sprayed with an electromagnetic absorption coating or an additional electromagnetic absorption structure layer 6, which effectively improves the electromagnetic stealth performance of the combined structure.

[0062] Next, the application provides some steps and implementation methods for the preferred embodiment in use. When the easy folding and unfolding combined truss protective structure is in an unfolded stable state, it has a certain normal bearing capacity, and the bearing performance is related to the size, angle, material, etc. of the easy folding and unfolding combined truss protective structure; when the easy folding and unfolding combined truss protective structure is transformed from the unfolded bearing state to the folded state, the normal direction of the upper plane to the upper plane is the stretching direction of the I-shaped rod, the I-shaped rod is rotated until the plane multi-edges of the upper plane and the plane multi-edges of the lower plane are initially parallel to each other, and after reaching the parallel state, the upper panel is compressed in the normal direction of the upper panel; when the easy folding and unfolding combined truss protective structure is transformed from the folded state to the unfolded bearing state, the upper panel is directly stretched or stretched and rotated until the combined structure reaches the unfolded stable state.

[0063] The application also provides a design method of a foldable combined truss protective structure based on a Kresling configuration, and specifically comprises the following steps:

[0064] Step S1: numerical calculation and checking of the foldability of the foldable combined truss protective structure to be designed;

[0065] Step S2: calculation and simulation of a real penetration explosion case by using a material penetration resistance and structure blast resistance performance theoretical calculation formula and combining a finite element modeling method, so as to calculate the material type and penetration resistance thickness of the upper panel and the lower panel, and confirm the protective performance of the upper panel and the lower panel;

[0066] Step S3: establishment of a penetration blast resistance calculation model of the foldable combined truss protective structure by using a finite element modeling method, determination of the truss structure form, material selection and rod size, and determination of the penetration blast resistance performance of the foldable combined truss protective structure according to the deformation damage degree, energy absorption size and blast isolation performance of the foldable combined truss protective structure under the action of an explosion impact load;

[0067] Step S4: protective performance test verification of the foldable combined truss protective structure model after numerical calculation and optimization design, verification of the bullet penetration resistance performance, deformation damage process and degree, energy absorption characteristics and blast isolation performance of the combined structure, and final determination of the combined structure form meeting the protective index;

[0068] Step S5: preparation of the upper panel, the lower panel, the I-shaped rod and the II-shaped rod according to the combined structure form and parameters after optimization design;

[0069] Step S6: tight connection of the two ends of each I-shaped rod and II-shaped rod with the upper panel and the lower panel in the combined structure, limitation of the linear displacement of the I-shaped rod and the II-shaped rod, and formation of a stable and reliable connection node.

[0070] Specific case:

[0071] In order to make the application more persuasive, a specific case is provided here to perform numerical calculation and verification on the foldable performance of the Kresling combined truss protective structure designed:

[0072] (1) First, a Kresling combined truss protective structure finite element model is established, and the existence of the upper panel and the lower panel has no obvious influence on the foldable performance, so the model is omitted, as shown in Figure 9 The angle between the I-shaped rod and the lower panel is 50°, and the angle between the II-shaped rod and the lower panel is 80°;

[0073] (2) In the present application, the I-shaped rod is easily stretched and deformed by the spring inside the I-shaped rod, and the hollow compression-resistant circular tube outside the I-shaped rod bears the compression load, that is, the I-shaped rod has a low tensile modulus and a high compression modulus in the mechanical aspect, and in the finite element model, it is simplified into a homogeneous material and is given different tensile modulus and compression modulus, and in the present example, the tensile modulus of the I-shaped rod is 21 MPa, and the compression modulus is 210 GPa. Since the II-shaped rod is not easy to deform, the tensile modulus and the compression modulus of the II-shaped rod are both 210 GPa;

[0074] (3) The easy-to-fold and deployable combined truss protective structure based on the Kresling configuration provided in the present application is path-optimized in folding, first rotating around the normal direction of the upper and lower panels towards the stretching direction of the I-shaped rod, and then compressing the normal direction of the upper panel after rotating to the initial mutual parallel of the four edges of the upper panel and the lower panel (in the example, the upper panel and the lower panel are set to be quadrilaterals), as shown in the left figure in Figures 10a-10b . In this folding process, the I-shaped rod is obviously stretched and deformed, and the II-shaped rod and the upper and lower panel frames are little deformed and can be ignored, and the required external force work in the folding process is shown by the circular dot line close to the horizontal coordinate axis in Figure 11 . The calculation result verifies the foldable and low work characteristics of the designed combined structure;

[0075] (4) In order to compare the superiority of the present application, a Kresling combined truss protective structure as shown in Figure 9 is also established, and the tensile modulus and the compression modulus of the I-shaped rod (without spring) and the II-shaped rod are both 210 GPa, and the compression folding process of the traditional Kresling combined truss protective structure is shown in the right figure in Figures 10a-10b . In the folding process, the I-shaped rod and the II-shaped rod are obviously deformed, and the required external force work is shown by the square dot line in Figure 11 .

[0076] (5) Through the folding process calculation result of the Kresling combined truss protective structure in the present Figures 10a-10b and the comparison of the external force work amount in the folding process between the easy-to-fold and deployable combined truss protective structure based on the Kresling configuration in the present application and the traditional Kresling truss structure in Figure 11 , the easy-to-fold characteristics of the Kresling combined truss protective structure are verified.

[0077] In summary, in the present application, the innovation points include three aspects. The first is the structural design aspect: the sandwich structure form of "hard-soft-hard" is adopted, the "hard" panel layer resists penetration, explosion and damage, the "soft" sandwich layer realizes efficient explosion isolation and explosion resistance through wave impedance mismatch with the surface layer; the traditional two-dimensional Kresling paper folding structure is equivalent to a one-dimensional truss structure, and the I-shaped member in the truss structure is innovatively designed as two parts, i.e., an internal tensile spring integrated with the connecting node and an external hollow compression-resistant circular tube separated from the connecting node of the I-shaped member, the easy deployment and easy folding of the combined structure can be realized through the tensile deformation of the internal spring of the I-shaped member, the folded combined structure saves space and is convenient for storage and transportation, and the external hollow compression-resistant circular tube of the I-shaped member realizes good bearing capacity through compression resistance; it is innovatively proposed that the included angle between the II-shaped member and the lower panel should be less than 90°, so that the combined structure has excellent normal compression bearing performance, and at this time, the bearing performance of the unfolded Kresling combined truss structure is stronger than when the included angle is greater than 90°, and it is more suitable for structural bearing.

[0078] The second is the innovation of folding mode. The combined structure in a stable state after unfolding needs to be first vertically lifted, rotated and then compressed and folded when folding. The pre-lifting and rotating operation can make the combined structure cross the energy barrier during the folding and unfolding process, reduce the energy required to provide in the folding process, and more easily realize folding and compression.

[0079] The third is the material composition aspect: the UHMWPE composite laminated plate is innovatively selected as the material of the upper and lower panels, the UHMWPE material has extremely low density of about 0.97 g / cm 3 , extremely high specific strength and specific modulus, and can achieve more than twice the ballistic protection efficiency of armor steel, and also has excellent explosion resistance, which is a high-quality penetration and explosion protection material; CFRP, GFRP or high-performance aluminum alloy is selected as the compression-resistant rod material, which is light in weight and has good compression resistance.

[0080] Those skilled in the art can understand that unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood as having meanings consistent with those in the prior art, and should not be interpreted in an idealized or overly formal sense unless otherwise defined.

[0081] The meaning of "and / or" described in the present application includes both individual existence and simultaneous existence.

[0082] The meaning of "connection" described in the present application can be direct connection between components or indirect connection between components through other components.

[0083] With the above ideal embodiments according to the present application as the inspiration, through the above description, relevant staff can make various changes and modifications without deviating from the scope of the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A flexible, deployable composite truss protective structure based on the Kresling configuration, characterized in that: It includes a top panel and a bottom panel, with a foldable truss core layer based on the Kresling configuration sandwiched between the top and bottom panels; The upper or lower panel may be polygonal or circular; The core layer of the foldable truss structure includes several type I members and type II members. The two ends of the type I members are respectively connected to the top plate and the bottom plate. Similarly, the two ends of the type II members are respectively connected to the top plate and the bottom plate. At each connection point on the top or bottom panel, a Type I member and a Type II member are simultaneously installed. When the combined truss protective structure is under load, the angle between the Type I member and the lower panel is less than 90°, and similarly, the angle between the Type II member and the lower panel is less than 90°. Define a structure consisting of a Type I member and a Type II member. In each structure, one end of the Type I member and one end of the Type II member in the adjacent structure are connected to the same junction point on the top plate. The other end of the Type I member and the other end of the Type II member in each structure are connected to the same junction point on the bottom plate. The other end of the Type II member and the end of the Type I member in the adjacent structure are connected to the same junction point on the top plate. The type I rod includes an outer hollow pressure-resistant round tube and an inner spring. The inner spring passes through the outer hollow pressure-resistant round tube and is connected to the connection node of the type I rod at both ends where it extends out of the outer hollow pressure-resistant round tube. Type I member connection nodes are used to connect Type I members to the upper or lower panel; The type II rod includes a type II cylindrical rod body, with type II rod connection nodes connected to both ends of the type II cylindrical rod body; Type II member connection nodes are used to connect Type II members to the upper or lower panel; When the easily deployable modular truss protective structure is in a stable deployed state, it has load-bearing capacity in the normal direction, and the load-bearing capacity matches the size, angle, and material of the easily deployable modular truss protective structure. When the easily foldable combined truss protective structure changes from the unfolded load-bearing state to the folded state, the normal direction of the upper plane and the lower plane is the tension direction of the type I member. The type I member is rotated until the plane polygon of the upper plane and the plane polygon of the lower plane are initially parallel to each other. After they are parallel to each other, the upper panel is compressed in the normal direction of the upper panel. When the easily foldable combined truss protective structure changes from a folded state to an unfolded load-bearing state, the upper panel is directly stretched or rotated until the combined structure reaches a stable state after unfolding.

2. The easily deployable combined truss protective structure based on the Kresling configuration according to claim 1, characterized in that: The upper or lower panel is made of high-performance FRP material; The Type I or Type II members are made of high-performance FRP material.

3. The easily deployable combined truss protective structure based on the Kresling configuration according to claim 2, characterized in that: In the top or bottom panel, the aforementioned high-performance FRP material is a hot-pressed laminate of ultra-high molecular weight polyethylene composite material; In Type I or Type II members, the aforementioned high-performance FRP material is CFRP, GFRP, BFRP, or high-performance aluminum alloy.

4. The easily deployable combined truss protective structure based on the Kresling configuration according to claim 1, characterized in that: The top and bottom panels are encapsulated with a polyurea coating.

5. The easily deployable combined truss protective structure based on the Kresling configuration according to claim 1, characterized in that: Apply an electromagnetic absorption coating or add an electromagnetic absorption structural layer to the outer surface of the top panel and the outer surface of the bottom panel.

6. A design method for a Kresling-based easily deployable composite truss protective structure as described in any one of claims 1-5, characterized in that: Specifically, the following steps are included: Step S1: Perform numerical calculations and verifications on the foldability of the easily foldable combined truss protective structure to be designed; Step S2: Using theoretical calculation formulas for material penetration resistance and structural explosion resistance, combined with finite element modeling, we will calculate and simulate real penetration explosion cases to determine the material type and penetration resistance thickness of the upper and lower panels, and confirm the protective performance of the upper and lower panels. Step S3: Establish a penetration and blast resistance calculation model of the easily deployable composite truss protective structure using the finite element modeling method, determine the truss structure form, material selection and member size, and clarify the penetration and blast resistance performance of the easily deployable composite truss protective structure based on the degree of deformation and damage, energy absorption and explosion isolation performance of the easily deployable composite truss protective structure under explosive impact load. Step S4: Conduct protective performance tests on the easily foldable combined truss protective structure model after numerical calculation and optimization design to verify the bullet penetration resistance, deformation and failure process and degree, energy absorption characteristics and explosion-proof and wave-damping performance of the combined structure, and finally determine the combined structure form that meets the protection index. Step S5: Prepare the upper panel, lower panel, Type I members, and Type II members according to the optimized design of the combined structure and parameters; Step S6: The two ends of each Type I and Type II member are tightly connected to the upper and lower panels of the composite structure, respectively, to restrict the linear displacement of the Type I and Type II members and form a stable and reliable connection node.

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