Design method for cell interlocking of composite sandwich structures to improve shear performance

Abstract

To provide a method for designing cell interlocking in composite sandwich structures to improve shear performance.SOLUTION: This invention comprises the steps of: determining a placement pattern of cells of a first sandwich layer based on the design requirements of a composite sandwich structure, and constructing a geometric shape feature model of N-1 type cells of the first sandwich layer; constructing a geometric shape feature model of a NS-1 type interlocking cell of a second sandwich layer based on the structural constraints of interfacial interlocking cells and the geometric shape feature model of the N-1 type cells of the first sandwich layer; and finally calculating cell placement positioning points based on the position constraints of the interfacial interlocking cells, generating a design plan for cell interlocking of the composite sandwich structure with improved shear performance, and achieving the improvement of the shear performance of the composite sandwich structure through the cell interlocking. The present invention solves the problem that the conventional polyhedral composite sandwich structure has insufficient shear resistance when subjected to shear load, resulting in structural instability, and provides an interlocking design plan for the polyhedral composite sandwich structure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for designing a composite sandwich structure, and more particularly to a method for designing cell interlocking in a composite sandwich structure to improve shear performance. [Background technology]

[0002] A composite sandwich structure is a sandwich structure consisting of upper and lower panels, a middle sandwich structure, and an adhesive layer between the panels and the sandwich structure. Inspired by natural materials and the art of origami, composite sandwich structures have excellent specific stiffness and strength, making them widely used in the transportation industry. Their excellent energy absorption capabilities also make them suitable for protective structures. Furthermore, sandwich structures have many internal gaps, providing a certain degree of vibration and noise reduction. Therefore, sandwich structures are widely used in science and engineering, including tanks for tank trucks, chassis for electric vehicles, building walls, and the upper covers of high-speed rail cars.

[0003] However, when composite sandwich structures are subjected to shear loads, their mechanical properties have a direct negative impact on the stability and safety of the structure. While the shear strength of most composite sandwich structures primarily depends on the strength of the core structure, when conventional polyhedral sandwich structures are subjected to shear loads, they are supported solely by the adhesive between the core and the panels, significantly reducing the shear resistance of the polyhedral sandwich structure. Currently, most N-1 type polyhedral composite sandwich structure designs are single-layer sandwich structures with low shear strength, and there is a lack of design methods to improve the shear performance of the cells in composite sandwich structures.

[0004] Furthermore, the pressurized magazine using a truss core described in Patent Document 1 is disclosed to include a truss core assembly formed by stacking two truss cores, each consisting of a flat sheet member and a plurality of triangular pyramidal protrusions extending up from one side of the sheet member over the entire surface of the sheet member, the interior of each triangular pyramidal protrusion being hollow, with the surfaces with the protrusions facing each other and the apex of the protrusion of one truss core offset from the apex of the protrusion of the other truss core, and a plurality of flat plate-shaped pressing plate members arranged in contact with each other on both sides of the truss core assembly. However, there is no description of a design method for the sandwich structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. JP2011245815A Summary of the Invention

[0006] To solve the problem that the conventional design of composite sandwich structures lacks a design method for improving the shear performance of cells in polyhedral composite sandwich structures, the present invention provides a design method for cell interlocking of composite sandwich structures to improve shear performance. The present invention determines the size of the composite sandwich structure panel and the layout pattern of the cells in the first sandwich layer based on the design requirements of the composite sandwich structure, obtains the design constraints of the N-1 type cells in the first sandwich layer, and determines the N-1 type cells in the second sandwich layer based on the design constraints of the N-1 type cells in the first sandwich layer and the structural constraints of the interlocking cells. S -Calculate the geometric shape feature model of the type 1 interlocking cell, calculate the placement positioning points of the cells of the composite sandwich structure based on the position constraints of the interlocking cell, and construct a design proposal for the cell interlocking of the composite sandwich structure with improved shear performance.

[0007] The technical means of the present invention are as follows.

[0008] First, the design method of cell interlocking of composite sandwich structure to improve shear performance is as follows: (1) determining the layout pattern of the cells of the first sandwich layer according to the design requirements of the composite sandwich structure, calculating the radius R of the circular envelope of the bottom surface of the N-1 type cell of the first sandwich layer, and constructing a geometric shape feature model of the N-1 type cell of the first sandwich layer; (2) Based on the structural constraints of the interdigitated cells and the geometric shape feature model of the N-1 type cells of the first sandwich layer, the N-1 type cells of the second sandwich layer are calculated. S - constructing a geometric shape feature model of the type 1 interlocking cell; (3) Geometric shape feature model of N-1 type cell in the first sandwich layer, N S - The method includes a step of calculating cell placement positioning points based on the geometric shape feature model of the type 1 interlocking cell and the position constraints of the interlocking cell, and generating a design proposal for cell interlocking of a composite sandwich structure with improved shear performance.

[0009] Specifically, the design requirements for the composite sandwich structure are as follows: the length of the long side of the panel of the composite sandwich structure is a, the length of the short side is b, the number of N-1 type cells arranged in the long side direction of the rectangular panel of the first sandwich layer is n, the number of cells arranged in the short side direction is m, the number of sides of the regular polygon of the bottom surface of the N-1 type cell of the first sandwich layer is N, and the relative density of the first sandwich layer is ρ - , N of the second sandwich layer S The number of sides of the regular polygon of the base of the -1 type interlocking cell is N S (N S ≧N).

[0010] The cell arrangement pattern of the first sandwich layer is specifically a high-density aligned arrangement pattern and a high-porosity staggered arrangement pattern, JPEG0007795173000001.jpg55170The specific calculation formula is: JPEG0007795173000002.jpg16150.

[0011] The formula for calculating the radius R of the circular envelope of the bottom surface of the N-1 type cell of the first sandwich layer is: In the case of a high density aligned arrangement pattern, JPEG0007795173000003.jpg63170,

[0012] In the case of a high porosity staggered pattern, JPEG0007795173000004.jpg97170,

[0013] In the formula, a and b are the lengths of the long and short sides of the panel of the composite sandwich structure, respectively, N is the number of sides of the regular polygon of the base of the N-1 type cell of the first sandwich layer, and n and m are the number of N-1 type cells of the first sandwich layer arranged in the long side direction and the short side direction of the rectangular panel, respectively.

[0014] Specifically, the geometric shape feature model of the N-1 type cell of the first sandwich layer is such that the side length of the regular N-gon on the bottom surface of the N-1 type cell of the first sandwich layer is L N , the height of the isosceles triangle on the side is H f N , the height of the three-dimensional structure is H h N , the three-dimensional bending angle is α, and the edge angle is β. JPEG0007795173000005.jpg85156

[0015] The structural constraints of the interdigitated cells are specifically the N-1 type cells in the first sandwich layer and the N S The three-dimensional bending angles of the N-1 type interlocking cells are equal, and the N-1 type cells of the first sandwich layer and the N-1 type cells of the second sandwich layer S The height of the three-dimensional structure of the -1 type mating cell is equal.

[0016] JPEG0007795173000006.jpg80170

[0017] N of the second sandwich layer SSpecifically, the geometric shape feature model of the N-1 type interlocking cell is calculated based on the number of sides N of the regular polygon of the base of the N-1 type cell of the first sandwich layer, and the number of sides N of the N-1 type cell of the second sandwich layer. S -Number of sides of the regular polygon of the base of the 1-type interlocking cell N S (N S ≧N) and select N of the second sandwich layer based on the structural constraints of the interdigitated cells of the composite sandwich structure. S -1 type interlocking cell bottom circular envelope radius R s , positive N on the bottom s Side length L of the polygon s N , the height of the isosceles triangle on the side H sf N , edge angle β s Calculate. JPEG0007795173000007.jpg65170

[0018] Specifically, the calculation of the placement positioning point of the cell is performed as follows: First, the bottom side of the N-1 type cell of the first sandwich layer is overlapped with the long side of the bottom plate of the first sandwich layer, and the positioning point of the lower left corner of the bottom plate of the first sandwich layer is set as the coordinate origin, the long side of the bottom plate of the first sandwich layer is set as the x-axis, the side perpendicular to the long side of the bottom plate of the first sandwich layer is set as the y-axis, and the direction parallel to the height of the three-dimensional structure of the cell is set as the z-axis;

[0019] JPEG0007795173000008.jpg52170 (wherein i represents the row number of the cell in the first sandwich layer, and j represents the column number of the cell in the first sandwich layer.) and

[0020] JPEG0007795173000009.jpg33170 (wherein i represents the row number of the cell in the second sandwich layer, and j represents the column number of the cell in the second sandwich layer.) is.

[0021] Second, a device for designing cell interlocking of a composite sandwich structure to improve shear performance includes an input module, a calculation module, and an output module; The input module is used to input the design requirement information of the composite sandwich structure input by the user and send the design requirement information to the calculation module; The calculation module receives design requirement information, and calculates a surface-to-surface fit constraint, a geometric feature model of the N-1 type cell of the first sandwich layer, and a geometric feature model of the N-1 type cell of the second sandwich layer. S Calculate the geometric shape feature model of the N-1 type cell and the placement positioning point of the cell, and calculate the geometric shape feature model of the N-1 type cell of the first sandwich layer, the N-1 type cell of the second sandwich layer, S -1 type cell geometric shape feature model and cell placement positioning point are used to send to the output module; The output module outputs the geometric feature model of the N-1 type cell of the first sandwich layer, the N S The system receives the geometric shape feature model of the -1 type cell and the cell placement positioning points, and outputs a design proposal for cell fitting of a composite sandwich structure with improved shear performance.

[0022] The beneficial effect of the present invention is that the method of the present invention is a design method for improving the interlocking performance of cells in a polyhedral composite sandwich structure, which solves the problem that the conventional polyhedral composite sandwich structure has insufficient shear resistance and becomes unstable when subjected to shear load, and provides an interlocking design plan for a composite sandwich structure with improved shear performance. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram of a 3-1 type cell. [Figure 2] Schematic diagrams of the arrangement pattern of 3-1 type cells in the first sandwich layer of a composite sandwich structure, where (a) is a schematic diagram of a high-density aligned arrangement pattern of 3-1 type cells in the first sandwich layer, and (b) is a schematic diagram of a high-porosity staggered arrangement pattern of 3-1 type cells in the first sandwich layer. [Figure 3] 1A and 1B are schematic diagrams of NS-1 type interlocking cells of the second sandwich layer, (a) is a schematic diagram of 3-1 type interlocking cells of the second sandwich layer, (b) is a schematic diagram of 4-1 type interlocking cells of the second sandwich layer, (c) is a schematic diagram of 5-1 type interlocking cells of the second sandwich layer, and (d) is a schematic diagram of 6-1 type interlocking cells of the second sandwich layer. [Figure 4] Schematic diagrams of composite sandwich structures based on 3-1 type cells in a first sandwich layer in a high-density aligned arrangement pattern, (a) is a schematic diagram of a composite sandwich structure of 3-1 type cells in a first sandwich layer and 3-1 type interdigitated cells in a second sandwich layer in a high-density aligned arrangement pattern, (b) is a schematic diagram of a composite sandwich structure of 3-1 type cells in a first sandwich layer and 4-1 type interdigitated cells in a second sandwich layer in a high-density aligned arrangement pattern, (c) is a schematic diagram of a composite sandwich structure of 3-1 type cells in a first sandwich layer and 5-1 type interdigitated cells in a second sandwich layer in a high-density aligned arrangement pattern, and (d) is a schematic diagram of a composite sandwich structure of 3-1 type cells in a first sandwich layer and 6-1 type interdigitated cells in a high-density aligned arrangement pattern. [Figure 5] Schematic diagrams of composite sandwich structures based on 3-1 type cells in the first sandwich layer in a high-porosity staggered pattern: (a) a schematic diagram of a composite sandwich structure of 3-1 type cells in the first sandwich layer and interdigitated 3-1 type cells in the second sandwich layer in a high-porosity staggered pattern; (b) a schematic diagram of a composite sandwich structure of 3-1 type cells in the first sandwich layer and interdigitated 4-1 type cells in the second sandwich layer in a high-porosity staggered pattern; (c) a schematic diagram of a composite sandwich structure of 3-1 type cells in the first sandwich layer and interdigitated 5-1 type cells in the second sandwich layer in a high-porosity staggered pattern; and (d) a schematic diagram of a composite sandwich structure of 3-1 type cells in the first sandwich layer and interdigitated 6-1 type cells in the second sandwich layer in a high-porosity staggered pattern. [Figure 6] 1 is a schematic diagram of cell placement positioning points of the present invention; [Figure 7] 1 is a flow chart of the method steps of the present invention. [Figure 8] 1 is a block diagram of an apparatus according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will be described in detail below by way of examples with reference to the accompanying drawings, in which a 3-1 type cell of the first sandwich layer is taken as an example, and the structure of the cell is shown in FIG.

[0025] As shown in FIG. 7, the present invention (1) determining the arrangement pattern of the cells of the first sandwich layer according to the design requirements of the composite sandwich structure, and constructing a geometric shape feature model of the N-1 type cells of the first sandwich layer; (2) Based on the structural constraints of the interdigitated cells and the geometric shape feature model of the N-1 type cells of the first sandwich layer, the N-1 type cells of the second sandwich layer are calculated. S - constructing a geometric shape feature model of the type 1 interlocking cell; (3) Calculating the placement positioning points of the cells based on the position constraints of the interfacial interlocking cells, generating a design proposal for the cell interlocking of a composite sandwich structure with improved shear performance, and realizing the improvement of the shear performance of the composite sandwich structure through the cell interlocking.

[0026] Here, the step of constructing a geometric shape feature model of the N-1 type cell of the first sandwich layer based on the design requirements of the composite sandwich structure specifically includes: First, based on the design requirements of the composite sandwich structure, the layout pattern of the cells in the first sandwich layer is determined, the radius R of the circular envelope of the base of the N-1 type cell in the first sandwich layer is calculated, and a geometric shape feature model of the N-1 type cell in the first sandwich layer is constructed. The N-1 type cell is a three-dimensional regular polyhedron with a regular N-gon base and N isosceles triangles with the same side length as the base, folded along the sides of the regular N-gon base. The design requirements for the composite sandwich structure are: a = a, b = b; n = n-1 = m; and m = m = m.

[0027] In this example, the dimensions of the panels of the composite sandwich structure are a × b, with the long side dimension of the rectangular panel being a = 90 mm and the short side dimension being b = 60 mm. The number of N-1 type cells arranged in the long side direction of the rectangular panel of the first sandwich layer is n = 4, and the number of cells arranged in the short side direction is m = 5. The number of sides of the regular polygon of the base of the N-1 type cell of the first sandwich layer is N = 3, JPEG0007795173000010.jpg29170

[0028] JPEG0007795173000011.jpg76170

[0029] As shown in FIG. 2(a), when the arrangement pattern of the cells in the first sandwich layer is a high-density aligned arrangement pattern, the formula for calculating the radius R of the circular envelope of the bottom surface of the N-1 type cell in the first sandwich layer is: JPEG0007795173000012.jpg47170.

[0030] As shown in Figure 2(b), when the cell arrangement pattern of the first sandwich layer is a high-porosity staggered arrangement pattern, the formula for calculating the radius R of the circular envelope of the bottom surface of the N-1 type cell of the first sandwich layer is: JPEG0007795173000013.jpg88170.

[0031] In this example, the relative density ρ of the first sandwich layer - is greater than ρ0, the arrangement pattern of the cells in the first sandwich layer is a high-density aligned arrangement pattern, and the radius R of the circular envelope of the bottom surface of the 3-1 type cell in the first sandwich layer is the design constraint of the composite sandwich structure. The specific calculation formula is: JPEG0007795173000014.jpg33170.

[0032] The construction of the geometric shape feature model of the N-1 type cell of the first sandwich layer is specifically as follows: JPEG0007795173000015.jpg88170

[0033] The specific calculation formula for the geometric shape feature model of the 3-1 type cell of the first sandwich layer is: JPEG0007795173000016.jpg98170.

[0034] The structural constraints of the interfacial fit of the composite sandwich structure are the N-1 type cells in the first sandwich layer and the N type cells in the second sandwich layer. S -The three-dimensional bending angles of the 1-type interlocking cells are equal, JPEG0007795173000017.jpg35170

[0035] The position constraints of the interfacial fit of the composite sandwich structure are the positioning points of the N-1 type cells of the first sandwich layer and the N S The lateral distance between the positioning point of the -1 type mating cell and the positioning point is Δx=0, JPEG0007795173000018.jpg66170

[0036] Based on the geometric feature model of the N-1 type cell of the first sandwich layer, in combination with the structural constraints of the interfacial fit of the composite sandwich structure, the N-1 type cell of the second sandwich layer is S Specifically, determining the geometric shape feature model of the -1 type interdigitated cell involves: N of the second sandwich layer S -1 type interlocking cell has a positive N bottomS N is a polygon with staggered sides and the base is the same as the side length of the base S N isosceles triangles with sides equal to the base S A regular polyhedron is a three-dimensional polyhedron formed by folding along the sides of a polygon. Schematic diagrams of the 3-1, 4-1, 5-1, and 6-1 regular interdigitated cells are shown in Figure 3(a) to (d), respectively. JPEG0007795173000019.jpg24170

[0037] JPEG0007795173000020.jpg91170

[0038] In this example, N S = 4, and N of the second sandwich layer S The specific calculation formula for the geometric feature model of the -1 type interlocking cell is: JPEG0007795173000021.jpg101170

[0039] JPEG0007795173000022.jpg41170.

[0040] Based on the position constraints of the inter-face fitting cells, JPEG0007795173000023.jpg42170

[0041] FIG. 8 is a diagram showing the configuration of a design device for cell interlocking of a composite sandwich structure to improve shear performance according to the present invention.

[0042] The apparatus includes an input module for inputting design requirement information of a composite sandwich structure input by a user and transmitting the design requirement information to a calculation module; and a calculation module for receiving the design requirement information and calculating inter-face fitting constraints, a geometric shape feature model of an N-1 type cell of a first sandwich layer, and an N-1 type cell of a second sandwich layer. S Calculate the geometric shape feature model of the N-1 type cell and the placement positioning point of the cell, and calculate the geometric shape feature model of the N-1 type cell of the first sandwich layer, the N-1 type cell of the second sandwich layer, Sa calculation module for transmitting a geometric shape feature model of the N-1 type cell of the first sandwich layer and a placement positioning point of the cell to an output module; S and an output module for receiving a geometric shape feature model of the -1 type cell and a placement positioning point of the cell, and outputting a design proposal for cell fitting of a composite sandwich structure with improved shear performance.

[0043] It should be noted that the above examples and explanations are only for explaining the technical means of the present invention, and are not intended to limit the present invention. Those skilled in the art will understand that modifications or equivalent replacements of the technical means of the present invention can be made, and as long as they do not deviate from the spirit and scope disclosed in the technical means of the present invention, they should all be included in the scope of the claims of the present invention.

Claims

1. 1. A method for designing cell interlocking in a composite sandwich structure to improve shear performance, comprising: (1) determining the layout pattern of the cells of the first sandwich layer according to the design requirements of the composite sandwich structure, calculating the radius R of the circular envelope of the bottom surface of the N-1 type cell of the first sandwich layer, and constructing a geometric shape feature model of the N-1 type cell of the first sandwich layer; (2) Based on the structural constraints of the interdigitated cells and the geometric shape feature model of the N-1 type cell of the first sandwich layer, the N-1 type cell of the second sandwich layer is calculated. Ｓ - constructing a geometric feature model of a type 1 interdigitated cell; (3) Geometric shape feature model of N-1 type cell of the first sandwich layer, N Ｓ - Calculating cell placement positioning points based on the geometric shape feature model of the type 1 interlocking cell and the position constraints of the interlocking cell, and generating a design proposal for the interlocking cell of the composite sandwich structure with improved shear performance; Including, The N-1 type cell is a three-dimensional regular polyhedron formed by folding a regular N-gon base along each side of the N-gon base, a staggered side consisting of N isosceles triangles with the side length of the base being the same as the base, and these isosceles triangles are arranged in a staggered manner. A method for designing cell interlocking in a composite sandwich structure to improve shear performance, comprising:

2. Specifically, the design requirements of the composite sandwich structure are as follows: the length of the long side of the panel of the composite sandwich structure is a, the length of the short side is b, the number of N-1 type cells arranged in the long side direction of the rectangular panel of the first sandwich layer is n, the number of cells arranged in the short side direction is m, the number of sides of the regular polygon of the bottom surface of the N-1 type cell of the first sandwich layer is N, The method for designing cell interlocking of a composite sandwich structure to improve shear performance according to claim 1 .

3. The cell arrangement pattern of the first sandwich layer is specifically a high-density aligned arrangement pattern and a high-porosity staggered arrangement pattern, The method for designing cell interlocking of a composite sandwich structure to improve shear performance according to claim 1, characterized in that:

4. The formula for calculating the radius R of the circular envelope of the bottom surface of the N-1 type cell of the first sandwich layer is: In the case of a high density aligned arrangement pattern, and In the case of a high porosity staggered pattern, and The method for designing cell fitting of a composite sandwich structure to improve shear performance according to claim 1, characterized in that, in the formula, a and b are the lengths of the long and short sides of the panel of the composite sandwich structure, respectively, N is the number of sides of the regular polygon of the base of the N-1 type cell of the first sandwich layer, and n and m are the number of N-1 type cells arranged in the long side direction and the short side direction of the rectangular panel of the first sandwich layer, respectively.

5. The geometric shape feature model of the N-1 type cell of the first sandwich layer is defined as follows: the side length of the regular N-gon on the bottom surface of the N-1 type cell of the first sandwich layer is L N , the height of the isosceles triangle on the side is H f N , the height of the three-dimensional structure is H h N The method for designing cell interlocking of a composite sandwich structure to improve shear performance according to claim 1, wherein the three-dimensional bending angle is α and the edge angle is β.

6. The structural constraints of the inter-face interlocking cells are specifically the N-1 type cells of the first sandwich layer and the N-1 type cells of the second sandwich layer. Ｓ The three-dimensional folding angles of the N-1 type interlocking cells are equal, and the N-1 type cells of the first sandwich layer and the N-1 type cells of the second sandwich layer are equal. Ｓ The method for designing cell interlocking of a composite sandwich structure to improve shear performance according to claim 1, characterized in that the heights of the three-dimensional structures of the -1 type interlocking cells are equal.

7. The positional constraints of the inter-surface interlocking cells are specifically the positioning points of the N-1 type cells of the first sandwich layer and the N-1 type cells of the second sandwich layer. Ｓ The lateral distance from the positioning point of the -1 type mating cell is Δx=0, The method for designing cell interlocking of a composite sandwich structure to improve shear performance according to claim 1 .

8. N of the second sandwich layer Ｓ Specifically, the geometric shape feature model of the N-1 type interlocking cell is calculated based on the number of sides N of the regular polygon of the base of the N-1 type cell of the first sandwich layer. Ｓ -Number of sides of the regular polygon of the base of the 1-type interlocking cell N Ｓ (N Ｓ ≧N) based on the structural constraints of the inter-face interlocking cells of the composite sandwich structure. N of the second sandwich layer Ｓ - Radius R of the circular envelope of the bottom of the 1-type interlocking cell s , positive N on the bottom s Side length L of the polygon s N , the height of the isosceles triangle on the side H sf N , edge angle β s The method for designing cell interlocking of a composite sandwich structure to improve shear performance according to claim 1, characterized in that:

9. Specifically, the calculation of the placement positioning point of the cell is performed as follows: 9.1) The bottom side of the N-1 type cell of the first sandwich layer is overlapped with the long side of the bottom plate of the first sandwich layer, and the positioning point of the lower left corner of the bottom plate of the first sandwich layer is the coordinate origin, the long side of the bottom plate of the first sandwich layer is the x-axis, the side perpendicular to the long side of the bottom plate of the first sandwich layer is the y-axis, and the direction parallel to the height of the three-dimensional structure of the N-1 type cell is the z-axis; (wherein i represents the row number of the cell in the first sandwich layer, and j represents the column number of the cell in the first sandwich layer). and 9.3) Based on the position constraints of the interdigitated cells, N of the second sandwich layer Ｓ -1 type mating cell positioning point (wherein i represents the row number of the cell in the second sandwich layer, and j represents the column number of the cell in the second sandwich layer). The method for designing cell interlocking of a composite sandwich structure to improve shear performance according to claim 1, characterized in that:

10. 1. A device for designing cell interlocking in a composite sandwich structure to improve shear performance, comprising: An input module, a calculation module, and an output module; The input module is used for inputting design requirement information of the composite sandwich structure input by a user and transmitting the design requirement information to a calculation module; The calculation module receives design requirement information, and calculates inter-face fit constraints, a geometric feature model of the N-1 type cell of the first sandwich layer, and a geometric feature model of the N-1 type cell of the second sandwich layer. Ｓ The geometric shape feature model of the N-1 type cell of the first sandwich layer and the placement positioning point of the cell are calculated, and the geometric shape feature model of the N-1 type cell of the second sandwich layer and the N-1 type cell of the second sandwich layer are calculated. Ｓ - Used to send the geometric shape feature model of the type 1 cell and the placement positioning point of the cell to the output module; The N-1 type cell is a three-dimensional regular polyhedron having a regular N-gon base, staggered sides consisting of N isosceles triangles with the side lengths of the base as bases, and is formed by arranging these isosceles triangles in a staggered manner and folding them along each side of the regular N-gon base, The output module outputs a geometric feature model of the N-1 type cell of the first sandwich layer, a geometric feature model of the N-1 type cell of the second sandwich layer, Ｓ A design device for cell fitting of a composite sandwich structure to improve shear performance, characterized in that it is used to receive a geometric shape feature model of a type-1 cell and placement positioning points of the cell, and to output a design proposal for cell fitting of a composite sandwich structure with improved shear performance.

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