Method for calculating bearing capacity of bamboo grating sandwich panel and preparation method of bamboo grating sandwich panel

Abstract

The invention discloses a bamboo grating sandwich panel and a bearing capacity calculation method thereof, and the method comprises the steps: calculating the local buckling bearing capacity of a solid sandwich panel component based on an energy method, and calculating the elastic modulus and shear modulus of a core body through an equivalent method; a correction coefficient related to the length-width ratio is introduced in combination with the orthotropic property of the panel material and the influence of the length on the local buckling bearing capacity, and a local buckling bearing capacity calculation formula is obtained through derivation; according to the method for calculating the overall buckling bearing capacity of the compression component based on the Euler buckling formula, the influence of shear deformation of a core body and orthotropic anisotropy of a panel material are comprehensively considered, and a calculation formula of the overall buckling bearing capacity of the bamboo grating sandwich panel under the in-plane axis compression effect is established. According to the method, stress characteristics and failure modes of the bamboo grating sandwich boards with different lengths under the in-plane axial pressure effect can be analyzed, and certain theoretical guidance is provided for research and application of the bamboo grating sandwich boards.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering structural boards, and particularly relates to a bamboo grille sandwich panel, a bearing capacity calculation method and a preparation method. Background Art

[0002] As a green and environment-friendly material with excellent mechanical properties, integrated bamboo has become the main development direction of modern bamboo structures. However, due to a series of complex technological processes such as slicing, gluing, embryo forming, and hot pressing in the preparation of integrated bamboo, its cost is twice that of plywood of the same specification; at the same time, in actual engineering applications, the structural form of integrated bamboo is relatively single, mostly solid plates or columns, and the material strength is difficult to be fully utilized, resulting in a certain amount of resource waste.

[0003] The grille sandwich structure is a representative lightweight structure. The upper and lower panels are used to bear bending, torsion and various in-plane loads, and the core body tightly bonded to the panels is responsible for transmitting compressive and out-of-plane shear loads. Due to its advantages such as high specific strength, high specific stiffness and designability, it has been widely used in the fields of aerospace, ship and ocean engineering, construction engineering, etc. However, the current applications mainly focus on grille sandwich panels made of fiber composite materials and foam materials, and the research scope of materials is relatively limited. At present, there is little research on bamboo grille sandwich panels, especially the research on the influence of length on their buckling modes and buckling bearing capacities has not yet had a clear and definite conclusion. More importantly, there is no current specification that proposes a calculation method for the bearing capacity of bamboo grille sandwich panels.

[0004] Therefore, it is necessary to analyze the mechanical characteristics and failure modes of bamboo grille sandwich panels with different lengths under in-plane axial compression, and propose a calculation method for the bearing capacity of different buckling modes of bamboo grille sandwich panels. Summary of the Invention

[0005] Object of the Invention: In order to overcome the above deficiencies, the object of the present invention is to provide a bamboo grille sandwich panel and its bearing capacity calculation method.

[0006] To solve the above technical problems, the present invention provides a bamboo grille sandwich panel and its bearing capacity calculation method, including:

[0007] Step S1: Calculate the local buckling bearing capacity of a sandwich panel specimen with isotropic panel material and solid core based on the energy method;

[0008] Step S2: Equivalently calculate the elastic modulus and shear modulus of the core and calculate the local buckling bearing capacity of orthotropic panel materials, and then calculate the local buckling bearing capacity of the bamboo grille sandwich panel;

[0009] Step S3: Calculate the overall buckling bearing capacity of the compression member based on the Euler buckling formula;

[0010] Step S4: Calculate the overall buckling bearing capacity of the bamboo grid sandwich panel under in-plane axial compression and eccentric compression according to the influence of the shear deformation of the sandwich panel core and the orthotropic properties of the panel material.

[0011] As a preferred embodiment of the present application, in step S1, the formula for calculating the local buckling bearing capacity of the sandwich panel specimen is:

[0012]

[0013] where A f is the cross-sectional area of the compressed panel, β is the buckling coefficient, E f is the elastic modulus of the panel, E c is the elastic modulus of the core material, G c is the shear modulus of the core material.

[0014] As a preferred embodiment of the present application, in step S2, the method includes:

[0015] The formula for calculating the equivalent elastic modulus is:

[0016]

[0017] where E is the elastic modulus of the component material, b is the spacing between adjacent long grids, and t is the thickness of the bamboo laminated board;

[0018] The formula for calculating the equivalent shear modulus is:

[0019]

[0020] where a is the spacing between adjacent short grids.

[0021] As a preferred embodiment of the present application, in step S2, the formula for calculating the local buckling bearing capacity of the orthotropic panel material is:

[0022]

[0023] where v is the Poisson's ratio in the orthogonal direction of the panel.

[0024] As a preferred embodiment of the present application, the sandwich panel is made of anisotropic integrated bamboo, the core material is in the form of a hollow grid sandwich, and the panel is adhesively bonded to the core through grooving. Therefore, considering the influence of the structural length on its bearing capacity, a coefficient related to the aspect ratio is introduced for correction, and thus the formula for calculating the local buckling bearing capacity of the bamboo grid sandwich panel is:

[0025]

[0026] As a preferred embodiment of the present application, in step S3, according to Euler's formula, the calculation formula for the overall buckling bearing capacity of the compression member is:

[0027]

[0028] where, (EI) eq is the equivalent stiffness of the cross-section of the sandwich panel under compression, where, d is the width of the sandwich panel member, c is the thickness of the sandwich panel member, h is the thickness of the grid core; L is the effective length of the panel, and for the simply supported boundary conditions at both ends, it is the actual length of the sandwich panel.

[0029] As a preferred embodiment of the present application, in step S4, considering the influence of the shear deformation of the core during the compression process of the sandwich panel on its bearing capacity, the calculation formula for its overall buckling bearing capacity is:

[0030]

[0031] where, (AG) eq is the equivalent shear stiffness of the sandwich panel, G is the shear modulus of the integrated bamboo material.

[0032] As a preferred embodiment of the present application, in step S4, considering the influence of the shear deformation of the core of the sandwich panel and the orthotropic properties of the panel material, the calculation formula for the overall buckling bearing capacity of the bamboo grid sandwich panel is:

[0033]

[0034] The present application also provides a bearing capacity calculation system for a bamboo grid sandwich panel using the above-mentioned bearing capacity calculation method, including:

[0035] A local buckling failure calculation module, which is used to calculate the local buckling bearing capacity of a sandwich panel specimen with isotropic panel material and solid core based on the energy method; equivalently calculate the elastic modulus and shear modulus of the core and calculate the local buckling bearing capacity of the orthotropic panel material, and then calculate the local buckling bearing capacity of the bamboo grid sandwich panel;

[0036] An overall buckling failure calculation module, which is used to calculate the overall buckling bearing capacity of the compression member and calculate the overall buckling bearing capacity of the sandwich panel during compression; according to the influence of the shear deformation of the core of the sandwich panel and the orthotropic properties of the panel material, calculate the overall buckling bearing capacity of the bamboo grid sandwich panel.

[0037] The present application also provides a bamboo grid sandwich panel, the bamboo grid sandwich panel uses the above-mentioned method to calculate the bearing capacity, and the preparation process of the bamboo grid sandwich panel is:

[0038] Select laminated bamboo with a first preset thickness as the base material for the first surface layer and the second surface layer, and mill grooves with preset dimensions on the laminated bamboo veneer according to a programmed path;

[0039] Select laminated bamboo with a second preset thickness as the base material for the first grid core layer and the second grid core layer;

[0040] Cut the second grid core layer along the direction perpendicular to the first grid core layer and assemble it into an orthogonal grid core layer;

[0041] Uniformly coat resorcinol adhesive in the grooves of the first surface layer. After the gluing is completed, position and place the orthogonal grid core layer on the first surface layer, and then send the assembled structure into a hydraulic cold press for laying treatment. After the laying is completed, cold press for a first preset time under a first preset pressure under a first preset condition;

[0042] Uniformly coat resorcinol adhesive in the grooves of the second surface layer. After the gluing is completed, place the orthogonal grid core layer and the first surface layer on the second surface layer, and then send the assembled structure into a hydraulic cold press for laying treatment. After the laying is completed, cold press for a second preset time under a second preset pressure under a second preset condition;

[0043] After the cold pressing is completed, use a cutting machine for cutting to make the bamboo grid sandwich panel.

[0044] The above technical solutions of this application have the following advantages compared with the prior art:

[0045] 1. The bearing capacity calculation of this application takes into account key factors such as the anisotropy of the panel of the bamboo grid sandwich panel and the shear deformation of the core material, making the calculation result closer to the actual stress situation and improving the accuracy of the bearing capacity calculation; furthermore, by comprehensively considering influencing factors such as local buckling, global buckling and shear deformation, the proposed calculation method can effectively predict the stability of the bamboo grid sandwich panel during the compression process.

[0046] 2. By introducing a correction coefficient related to the aspect ratio, this application can more reasonably evaluate the influence of the structural size on the buckling bearing capacity, provide a theoretical basis for the optimal design of the bamboo grid sandwich panel, and give full play to its structural performance.

[0047] 3. This application makes full use of the high specific strength and renewability of bamboo, combined with a reasonable mechanical calculation method, to make the bamboo grid sandwich panel have better mechanical properties. Description of the Drawings

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on the provided drawings.

[0049] Figure 1 It is a schematic diagram of the model of the bamboo grid sandwich panel provided by the embodiment of the present application.

[0050] Figure 2 It is a schematic diagram of the structure of the bamboo grid sandwich panel provided by the embodiment of the present application.

[0051] Figure 3 It is a plan view of the core layer of the bamboo grid sandwich panel provided by the embodiment of the present application.

[0052] Figure 4 It is a schematic diagram of the structure of the rectangular unit of the bamboo grid sandwich panel provided by the embodiment of the present application.

[0053] Figure 5 It is a cross-sectional view of the bamboo grid sandwich panel provided by the embodiment of the present application.

[0054] Figure 6 It is a schematic diagram of the loading device and the measuring point layout provided by the embodiment of the present application.

[0055] Figure 7 It is a schematic diagram of the module connection of the bearing capacity calculation system provided by the embodiment of the present application.

[0056] Description of the reference numerals in the specification drawings:

[0057] 1. First surface layer, 2. Second surface layer, 3. Orthogonal grid core layer, 3-1. First grid core layer, 3-2. Second grid core layer, 100. Local buckling failure calculation module, 101. Global buckling failure calculation module. Detailed implementation manners

[0058] The following will describe in detail the embodiments of the present invention. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0059] In some embodiments, the present application relates to a bamboo grid sandwich panel, and the preparation process of the bamboo grid sandwich panel is as follows:

[0060] Select integrated bamboo of a first preset thickness as the base material for the first surface layer 1 and the second surface layer 2, and mill the integrated bamboo veneer into a groove of a preset size according to the programmed path; select integrated bamboo of a second preset thickness as the base material for the first grid core layer 3-1 and the second grid core layer 3-2; cut the second grid core layer 3-2 in a direction perpendicular to the first grid core layer 3-1, and assemble them into orthogonal grid core layers.

[0061] The selected integrated bamboo must possess excellent mechanical properties and stability to ensure the overall load-bearing capacity of the bamboo grid sandwich panel. Furthermore, the first grid core layer 3-1 and the second grid core layer 3-2 must possess good structural support and ensure a uniform distribution of mechanical properties after the orthogonal grid structure is formed. During the processing of the grid core layers, the first grid core layer 3-1 is machined longitudinally, and the second grid core layer 3-2 is machined longitudinally. The resulting shapes include strips, blocks, and other structures.

[0062] Among them, the first preset thickness and the second preset thickness can be set to the same thickness or to different thicknesses, and the specific thickness size is set by the preparation personnel according to actual needs; the preset size is set by the preparation personnel according to actual needs; for example, in this application, the first preset thickness and the second preset thickness refer to the integrated bamboo with a thickness of 6-8mm, and the preset size adopts a groove depth of 2-3mm.

[0063] The resorcinol adhesive is evenly coated in the groove of the first surface layer 1. After the coating is completed, the orthogonal grid core layer 3 is positioned and placed on the first surface layer 1, and then the assembled structure is sent to the hydraulic cold press for laying. After the laying is completed, it is cold pressed at a first preset pressure under a first preset condition for a first preset time.

[0064] The amount of resorcinol adhesive applied is set by the preparation personnel according to actual needs. For example, in this application, the reference amount of adhesive is controlled at 260g / m 2 .

[0065] The resorcinol adhesive is evenly coated in the groove of the second surface layer 2. After the coating is completed, the orthogonal grid core layer 3 and the first surface layer 1 are placed on the second surface layer 2, and then the assembled structure is sent to a hydraulic cold press for laying. After the laying is completed, it is cold pressed at a second preset pressure under second preset conditions for a second preset time.

[0066] The amount of resorcinol adhesive applied is set by the preparation personnel according to actual needs. For example, in this application, the reference amount of adhesive is controlled at 260g / m 2 .

[0067] Among them, the first preset pressure and the second preset pressure can be set to the same pressure or different pressures, and the specific pressure is set by the preparer according to actual requirements; the first preset condition and the second preset condition can be set to the same condition or different conditions, and the specific condition is set by the preparer according to actual requirements; the first preset time and the second preset time can be set to the same time or different times, and the specific time is set by the preparer according to actual requirements; for example, in this application, the first preset pressure and the second preset pressure are preferably 1 MPa, the first preset condition and the second preset condition are preferably a temperature condition of 30 °C, and the first preset time and the second preset time are preferably 4 hours.

[0068] After cold pressing, a cutting machine is used for cutting to ensure that the dimensional accuracy of the bamboo grille sandwich panel meets the actual requirements, thereby completing the preparation of the bamboo grille sandwich panel.

[0069] Thus, the prepared bamboo grille sandwich panel is as shown in Figures 1 - 3 shown.

[0070] In some embodiments, the present application relates to a method for calculating the bearing capacity of a bamboo grille sandwich panel. The method includes local buckling failure and overall buckling failure. Specifically:

[0071] Local buckling failure:

[0072] Based on the energy method, the calculation formula for the local buckling bearing capacity of a sandwich panel specimen with an isotropic panel material and a solid core is:

[0073]

[0074] Among them, A f is the cross-sectional area of the panel under compression, β is the buckling coefficient, E f is the elastic modulus of the panel, E c is the elastic modulus of the core material, and G c is the shear modulus of the core material.

[0075] As shown in Figure 4 , for a core with an orthogonal grille structure form, the elastic modulus and shear modulus need to be equivalently calculated; for a rectangular unit structure, the equivalent elastic modulus can be expressed as:

[0076]

[0077] Among them, E is the elastic modulus of the component material, b is the spacing between adjacent long grilles, and t is the thickness of the bamboo laminated lumber board;

[0078] The calculation formula for the equivalent shear modulus is:

[0079]

[0080] Among them, a is the adjacent short grid spacing.

[0081] Considering the orthotropic properties of the panel material, its local buckling bearing capacity can be expressed as:

[0082]

[0083] Among them, v is the Poisson's ratio in the orthogonal direction of the panel.

[0084] The buckling coefficient β in the formula takes different values for different types of sandwich panels, and its value is generally determined through experiments. The panel of the sandwich panel prepared in the present invention is made of anisotropic integrated bamboo, the core material is in the form of a hollow grid sandwich, and the panel is adhesively bonded to the core through grooving. Therefore, it is also necessary to consider the influence of milling grooves on its material properties. The buckling coefficient of the bamboo grid sandwich panel is taken as 0.21. Considering the influence of the structural length on its bearing capacity based on the original formula, a coefficient related to the aspect ratio is introduced for correction:

[0085]

[0086] Among them, K is the aspect ratio of the sandwich panel.

[0087] Finally, the formula for calculating the local buckling bearing capacity of the bamboo grid sandwich panel is:

[0088]

[0089] Overall buckling failure:

[0090] According to Euler's formula, the formula for calculating the overall buckling bearing capacity of a compression member is:

[0091]

[0092] Among them, (EI) eq is the equivalent stiffness of the compression section of the sandwich panel, L is the effective length of the panel, and for the boundary condition of simply supported at both ends, it is the actual length of the sandwich panel; referring to Figure 5 as described, d is the width of the sandwich panel member, c is the thickness of the sandwich panel member, and h is the thickness of the grid core.

[0093]

[0094] Considering the influence of the core shear deformation of the sandwich panel during compression on its bearing capacity, its overall buckling bearing capacity is:

[0095]

[0096] Among them, (AG) eq is the equivalent shear stiffness of the sandwich panel.

[0097]

[0098] Among them, G is the shear modulus of the integrated bamboo material.

[0099] Therefore, considering the influence of the shear deformation of the sandwich panel core and the orthotropic properties of the panel material, the formula for calculating the overall buckling bearing capacity of the bamboo grid sandwich panel can be obtained as follows:

[0100]

[0101] Thus, in this application, in-plane axial compression test studies were carried out on 4 groups of bamboo grid sandwich panels with the same cross-section but different lengths. The theoretical cross-sectional dimensions of the specimens were 300 mm × 64 mm, and the lengths were 300 mm, 600 mm, 900 mm, and 1200 mm respectively. The research results show that the specimens with lengths of 300 mm, 600 mm, and 900 mm suffered local buckling failure under axial load; the specimen with a length of 1200 mm suffered overall buckling failure under axial load.

[0102] In this application, axial compression mechanical property tests were carried out on the bamboo grid sandwich panel, and the test design was carried out according to the "Standard for Test Methods of Wood Structures" (GB / T 50329—2012). The test was loaded by a 5000 kN microcomputer-controlled electro-hydraulic servo pressure testing machine, and the strain and lateral displacement data were collected using a Donghua DH3818Y static strain tester. During the loading process, the two ends of the specimen were hinged. To prevent local buckling at the ends of the specimen, resulting in the specimen not being able to fully exert its bearing capacity, fixtures were set at both ends of the specimen for reinforcement to allow the specimen to exert its material properties as much as possible. To understand the deformation of the specimen during the loading process, longitudinal and transverse strain gauges were arranged at the center positions of the two panels of the specimen, and at the same time, displacement gauges were placed on one surface at 1 / 4, 1 / 2, and 3 / 4 of the height direction of the plate to measure the lateral displacement of the plate when it was compressed. The test loading device and the layout of the measuring points are shown in the figure. The pressure testing machine was loaded at a constant speed of 0.5 mm / min until the specimen failed. At the same time, the Donghua test system collected the strain values and displacement values under the corresponding stress states to obtain test results such as bearing capacity, strain, and lateral deformation. Refer to Figure 6 as shown.

[0103] The finite element models of bamboo grid sandwich panels with 4 lengths were established using ABAQUS software, and the lengths were 300 mm, 600 mm, 900 mm, and 1200 mm respectively. The actual dimensions of the bamboo grid sandwich panel were used for the finite element model, and a bonded constraint was set between the panel and the core.

[0104] The comparison of the formula calculation values with the test values and the finite element calculation values is shown in the following table

[0105] Specimen number Calculated value by formula (kN) Test value (kN) Error Calculated value by finite element method (kN) Error BSP-L300 207.36 205.42 0.94％ 212.47 -2.46％ BSP-L600 194.66 189.16 2.83％ 198.03 -1.73％ BSP-L900 181.96 180.39 0.86％ 187.02 -2.78％ BSP-L1200 182.45 167.89 7.98％ 176.37 3.33％

[0106] The results show that the bamboo grid sandwich panel has good load-bearing capacity and can be used as a load-bearing member in engineering structures. Moreover, the calculation formula for the load-bearing capacity of the bamboo grid sandwich panel proposed in the present invention has high accuracy, and the error between the calculated value of the formula and the test value and the finite element calculated value is within 8%, which can provide a technical reference and theoretical basis for its engineering application.

[0107] Reference Figure 7 As shown, in some embodiments, the present application relates to a load-bearing capacity calculation system for a bamboo grid sandwich panel using the above load-bearing capacity calculation method, including:

[0108] The local buckling failure calculation module 100 is used to calculate the local buckling load-bearing capacity of a sandwich panel specimen with isotropic panel material and solid core based on the energy method; equivalently calculate the elastic modulus and shear modulus of the core and calculate the local buckling load-bearing capacity of the orthotropic panel material, and then calculate the local buckling load-bearing capacity of the bamboo grid sandwich panel;

[0109] The overall buckling failure calculation module 101 is used to calculate the overall buckling load-bearing capacity of a compression member and calculate the overall buckling load-bearing capacity of the sandwich panel during compression; calculate the overall buckling load-bearing capacity of the bamboo grid sandwich panel according to the influence of the core shear deformation of the sandwich panel and the orthotropic panel material.

[0110] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0111] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for calculating the bearing capacity of a bamboo grille sandwich panel, characterized in that, It includes the following steps: Step S1: Calculate the local buckling bearing capacity of a sandwich panel specimen with isotropic panel material and solid core based on the energy method; Step S2: Equivalently calculate the elastic modulus and shear modulus of the core, calculate the local buckling bearing capacity of the orthotropic panel material, and then calculate the local buckling bearing capacity of the bamboo grid sandwich panel; Step S3: Calculate the overall buckling bearing capacity of the compression member based on the Euler buckling formula; Step S4: Calculate the overall buckling bearing capacity of the bamboo grid sandwich panel under in-plane axial compression and eccentric compression according to the influence of the shear deformation of the core of the sandwich panel and the orthotropic properties of the panel material.

2. The bearing capacity calculation method of a bamboo grille sandwich panel according to claim 1, characterized in that, In step S1, the formula for calculating the local buckling bearing capacity of the sandwich panel specimen is: Among them, A f is the cross-sectional area of the panel under compression, β is the buckling coefficient, E f is the elastic modulus of the panel, E c is the elastic modulus of the core material, G c is the shear modulus of the core material.

3. The bearing capacity calculation method of a bamboo grille sandwich panel according to claim 1 or 2, characterized in that In step S2, the method includes: The formula for calculating the equivalent elastic modulus is: where E is the elastic modulus of the member material, b is the spacing between adjacent long grids, and t is the thickness of the bamboo laminated lumber board; The formula for calculating the equivalent shear modulus is: where a is the spacing between adjacent short grids.

4. The bearing capacity calculation method of a bamboo grille sandwich panel according to claim 2, characterized in that, In step S2, the formula for calculating the local buckling bearing capacity of the orthotropic panel material is: where v is the Poisson's ratio in the orthogonal direction of the panel.

5. The bearing capacity calculation method of a bamboo grille sandwich panel according to claim 4, characterized in that, where The face panel of the sandwich panel is made of anisotropic laminated bamboo, the core material is in the form of a hollow grid sandwich, and the panel is adhesively bonded to the core through grooving. Therefore, considering the influence of the structural length on its load-bearing capacity, a coefficient related to the aspect ratio is introduced for correction. Thus, the formula for calculating the local buckling load-bearing capacity of the bamboo grid sandwich panel is obtained as follows:

6. The bearing capacity calculation method of a bamboo grille sandwich panel according to claim 1 or 5, characterized in that, In step S3, according to the Euler formula, the formula for calculating the overall buckling bearing capacity of the compression member is: Among them, (EI) eq is the equivalent stiffness of the compression section of the sandwich panel, where d is the width of the sandwich panel member, c is the thickness of the sandwich panel member, h is the thickness of the grid core; L is the effective length of the panel. For the boundary conditions simply supported at both ends, it is the actual length of the sandwich panel.

7. The bearing capacity calculation method of a bamboo grille sandwich panel according to claim 6, characterized in that, In step S4, considering the influence of the shear deformation of the core of the sandwich panel on its bearing capacity during compression, the formula for its overall buckling bearing capacity is: Among them, (AG) eq is the equivalent shear stiffness of the sandwich panel, and G is the shear modulus of the integrated bamboo material.

8. The bearing capacity calculation method of a bamboo grille sandwich panel according to claim 7, characterized in that In step S4, considering the influence of the shear deformation of the core of the sandwich panel and the orthotropic properties of the panel material, the formula for calculating the overall buckling bearing capacity of the bamboo grid sandwich panel is:

9. A bearing capacity calculation system for a bamboo grille sandwich panel using the bearing capacity calculation method according to any one of claims 1-8, characterized in that, It includes: A local buckling failure calculation module for calculating the local buckling bearing capacity of a sandwich panel specimen with isotropic panel material and solid core based on the energy method; Equivalently calculate the elastic modulus and shear modulus of the core, calculate the local buckling bearing capacity of the orthotropic panel material, and then calculate the local buckling bearing capacity of the bamboo grid sandwich panel; An overall buckling failure calculation module for calculating the overall buckling bearing capacity of the compression member and calculating the overall buckling bearing capacity of the sandwich panel during compression; calculate the overall buckling bearing capacity of the bamboo grid sandwich panel according to the influence of the shear deformation of the core of the sandwich panel and the orthotropic properties of the panel material.

10. A bamboo grid sandwich panel, wherein the bearing capacity of the bamboo grid sandwich panel is calculated by the method according to any one of claims 1-8, characterized in that, The preparation process of the bamboo grid sandwich panel is as follows: Select laminated bamboo with a first preset thickness as the base material for the first surface layer and the second surface layer, and mill grooves with preset dimensions from the laminated bamboo veneer according to the programmed path; Select laminated bamboo with a second preset thickness as the base material for the first grid core layer and the second grid core layer; Cut the second grid core layer perpendicular to the first grid core layer and assemble it into an orthogonal grid core layer; Evenly coat resorcinol adhesive in the grooves of the first surface layer. After coating, position and place the orthogonal grid core layer on the first surface layer, and then send the assembled structure into a hydraulic cold press for laying treatment. After laying, cold press it at a first preset pressure under first preset conditions for a first preset time; The resorcinol adhesive is evenly coated in the grooves of the second surface layer. After the coating is completed, the orthogonal grid core layer and the first surface layer are placed on the second surface layer, and then the assembled structure is sent to a hydraulic cold press for laying treatment. After the laying is completed, it is cold pressed under the second preset pressure for the second preset time under the second preset conditions; After the cold pressing is completed, it is cut with a cutting machine to make the bamboo grid sandwich panel.

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