Method for predicting mechanical behavior of plate system lattice reinforced composite material

Abstract

The invention discloses a mechanical behavior prediction method for a plate system lattice reinforced composite material, and belongs to the field of novel lattice structure lattice unit models. The method specifically comprises the following steps: 1) establishing a triangular plate model; 2) thickening each triangular plate in the triangular plate model to obtain a 1 / 8 plate system dot matrix unit model; (3) mirror symmetry is conducted on the 1 / 8 plate system lattice unit model with the XOY plane, the YOZ plane and the ZOX plane in sequence, and a first plate system lattice structure model is obtained; 4) amplifying the first plate system lattice structure model to obtain a second plate system lattice structure model; 5) subtracting the second plate system lattice structure model from the cubic model with the side length of 2L to obtain a matrix material model; subtracting the matrix material model from the cubic model to obtain a reinforcement material model; after assembly, the plate system lattice structure reinforced composite material model is obtained; (6) carrying out grid division, and applying a stretching boundary condition; and respectively inputting material attributes, and carrying out numerical simulation on mechanical behaviors in the tensile process of the plate system lattice structure reinforced composite material.

Description

Technical Field

[0001] The present invention belongs to the field of design of novel lattice unit models of lattice structures, and particularly relates to a method for predicting the mechanical behavior of plate-based lattice reinforced composites. Background Art

[0002] In the field of engineering design, the mechanical behavior of lattice structure reinforced composites is a crucial research topic. The geometric shape of the lattice structure has an important influence on the stress-strain distribution of the system. Although traditional experimental measurement methods can qualitatively reflect the load transfer and two-phase deformation to a certain extent, they have obvious limitations and are difficult to systematically and comprehensively measure the influence of lattice structures of different shapes on the stress-strain distribution and mechanical properties of the system.

[0003] In recent years, with the rapid development of computer technology, finite element simulation technology has been increasingly widely used in the simulation of the mechanical behavior of plate-based lattice structures and has obtained relatively accurate performance prediction results. However, existing finite element simulation methods still have some deficiencies when facing plate-based lattice structures of different shapes, such as low computational efficiency and limited processing ability for complex geometric shapes. In order to overcome these deficiencies, a new modeling method for lattice units of plate-based lattice structures combined with finite element simulation technology is needed. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for predicting the mechanical behavior of plate-based lattice reinforced composites in view of the current situation of difficult modeling of the shape of lattice units of plate-based lattice structures in the prior art. The present invention can create plate-based lattice structures of various shapes. With the help of finite element simulation technology, the mechanical behavior of plate-based lattice structure reinforced composites is predicted, and the mechanical properties of the plate-based lattice structure are calculated.

[0005] The specific technical solution adopted by the present invention is as follows:

[0006] The present invention provides a method for predicting the mechanical behavior of plate-based lattice reinforced composites, and the specific steps are as follows:

[0007] S1: Create a cube model CUBIC with side length L in a 3D modeling software;

[0008] S2: Based on the number of plates N, establish a triangular plate model in a 3D modeling software;

[0009] S3: Thicken each triangular plate in the triangular plate model to obtain an eighth plate-based lattice unit model;

[0010] S4: Mirror-symmetrically transform the 1 / 8 plate-based lattice unit model obtained in step S3 with respect to the XOY plane in the Cartesian coordinate system. After merging, perform mirror-symmetric transformation with respect to the YOZ plane, and after merging again, perform mirror-symmetric transformation with respect to the ZOX plane to obtain the first plate-based lattice structure model;

[0011] S5: Double-expand the first plate-based lattice structure model obtained in step S4 along the X, Y, and Z axes of the Cartesian coordinate system to obtain the second plate-based lattice structure model;

[0012] S6: Establish a cube model BIGCUBIC with a side length of 2L; perform a subtraction operation of one solid from another in the modeling software. Subtract the second plate-based lattice structure model from the cube model BIGCUBIC to obtain the matrix material model; subtract the matrix material model from the cube model BIGCUBIC to obtain the reinforcement material model;

[0013] S6: Assemble the matrix material model and the reinforcement material model to obtain the plate-based lattice structure reinforced composite material model;

[0014] S7: Perform mesh generation on the plate-based lattice structure reinforced composite material model and apply tensile boundary conditions; respectively input the material properties of the matrix material and the reinforcement material, and perform numerical simulation on the mechanical behavior during the tensile process of the plate-based lattice structure reinforced composite material to obtain the Young's modulus, Poisson's ratio, strength, and elongation of the plate lattice structure composite material.

[0015] Preferably, the 3D modeling software includes AutoCAD, Blender, Rhino, Abaqus, or Ansys software.

[0016] Preferably, the 8 vertices of the cube model CUBIC are respectively (0, 0, 0), (0, 0, L), (0, L, L), (0, L, 0), (L, 0, 0), (L, 0, L), (L, L, L), (L, L, 0); the 8 vertices of the cube model BIGCUBIC are respectively (-L, -L, -L), (-L, -L, L), (-L, L, L), (-L, L, -L), (L, -L, -L), (L, -L, L), (L, L, L), (L, L, -L).

[0017] Preferably, the method for establishing the triangular plate model in step S2 is as follows:

[0018] S201: Input the coordinates of three vertices, all of which are located on the surface of the cube model CUBIC, and determine a triangular plate according to the three vertices;

[0019] S202: Based on the number of plates N, repeat step S201 N times to determine N triangular plates; the N triangular plates are combined to obtain the triangular plate model.

[0020] Preferably, in step S3, each triangular plate is thickened by T / 2 along its positive and negative normal directions respectively, so that the plate thickness is T, and a 1 / 8 plate system lattice unit model is obtained.

[0021] Preferably, step S4 is as follows:

[0022] S401: copying the 1 / 8 plate lattice unit model, and performing mirror symmetry with the XOY plane in a Cartesian coordinate system to obtain a 1 / 8 plate lattice unit symmetric model; merging the 1 / 8 plate lattice unit model and the 1 / 8 plate lattice unit symmetric model to obtain a 1 / 4 plate lattice unit model;

[0023] S402: copying the 1 / 4 plate lattice unit model, and performing mirror symmetry with the YOZ plane in a Cartesian coordinate system to obtain a 1 / 4 plate lattice unit symmetric model; merging the 1 / 4 plate lattice unit model and the 1 / 4 plate lattice unit symmetric model to obtain a 1 / 2 plate lattice unit model;

[0024] S403: copying the 1 / 2 plate lattice unit model, mirror-symmetric with the ZOX plane in the Cartesian coordinate system, and obtaining a 1 / 2 plate lattice unit symmetric model; merging the 1 / 2 plate lattice unit model and the 1 / 2 plate lattice unit symmetric model to obtain a first plate lattice structure model.

[0025] Preferably, step S5 is as follows:

[0026] S501: Copy 7 copies of the first plate system lattice structure model, and move them along the vectors (0, 0, -2L), (0, -2L, -2L), (0, -2L, 0), (-2L, 0, 0), (-2L, 0, -2L), (-2L, -2L, -2L), (-2L, -2L, 0), respectively;

[0027] S502: The first plate-based lattice structure model and the model moved in step S501 are merged to obtain a second plate-based lattice structure model.

[0028] Preferably, the mesh type in the mesh division in step S7 is 4-node tetrahedral unit, and the total number of mesh units is not less than 500,000.

[0029] Preferably, the stretching boundary condition in step S7 is set as follows:

[0030] S701: Set the maximum tensile strain E to a value range of 0.1% to 10%; set the tensile rate S to a value range of 0.0001s -1 ~0.01s -1 ;

[0031] S702: If the stretching direction is the X direction, then constrain the X-direction displacement of all grid nodes on the plane of X = -L to be 0, and apply an X-direction displacement to all grid nodes on the plane of X = L, with the displacement amount being 2L×E; if the stretching direction is the Y direction, then constrain the Y-direction displacement of all grid nodes on the plane of Y = -L to be 0, and apply a Y-direction displacement to all grid nodes on the plane of Y = L, with the displacement amount being 2L×E; if the stretching direction is the Z direction, then constrain the Z-direction displacement of all grid nodes on the plane of Z = -L to be 0, and apply a Z-direction displacement to all grid nodes on the plane of Z = L, with the displacement amount being 2L×E.

[0032] Preferably, in step S7, numerical simulation is carried out using finite element software such as ABAQUS, ANSYS or Comsol.

[0033] The present invention has the following beneficial effects compared with the prior art:

[0034] (1) The method provided by the present invention can generate a plate-based lattice structure reinforced composite material model with diverse shapes and a model close to the real shape of industrial production by setting the position and spatial orientation of the plate model, and has broad applicability. By calculating its mechanical behavior under load conditions, the internal stress and strain distribution of the plate-based lattice structure reinforced composite material can be revealed, which not only has important academic significance, but also provides guidance for the structural design of industrial materials.

[0035] (2) The method provided by the present invention is convenient for modeling and simple to operate, and only needs to control a small number of parameters such as the number of plates, node information and its thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The triangular plate model established for Example 1;

[0037] Figure 2 The 1 / 8 plate-based lattice unit model established for Example 1;

[0038] Figure 3 The first plate-based lattice structure model UNIT established for Example 1;

[0039] Figure 4 The second plate-based lattice structure model BIGUNIT established for Example 1;

[0040] Figure 5 The matrix material model MATRIX established for Example 1;

[0041] Figure 6 The reinforcement material model REINFORCEMENT established for Example 1;

[0042] Figure 7The plate lattice structure reinforced composite material model COMPOSITE established for Example 1;

[0043] Figure 8 The stress-strain relationship of 6061 aluminum in Example 1;

[0044] Figure 9 The stress nephogram of the plate lattice structure reinforced composite material in Example 1;

[0045] Figure 10 The simulated stress-strain curve of the plate lattice structure reinforced composite material in Example 1. Detailed implementation manners

[0046] The present invention will be further described and illustrated below in conjunction with the accompanying drawings and specific implementation manners. The technical features of each implementation manner in the present invention can be combined correspondingly without conflict.

[0047] The present invention provides a method for predicting the mechanical behavior of a plate lattice reinforced composite material, and the specific steps are as follows:

[0048] I. Establish a cubic model CUBIC

[0049] Create a cubic model CUBIC with side length L in a three-dimensional modeling software. The 8 vertices of the cubic model CUBIC are respectively (0, 0, 0), (0, 0, L), (0, L, L), (0, L, 0), (L, 0, 0), (L, 0, L), (L, L, L), (L, L, 0).

[0050] II. Establish a triangular plate model

[0051] (1) In a three-dimensional modeling software, select a triangular plate and input the number of plates N of the plate model; determine the plate thickness T.

[0052] (2) Input the coordinates of the three vertices P1 i (x1 i , y1 i , z1 i )、P2 i (x2 i , y2 i , z2 i )、P3 i (x3 i , y3 i , z3 i ) of the i-th plate, where i = 1, 2... N. The three vertices of each plate are all located on the surface of the cube CUBIC, and a triangular plate is determined according to the three vertices;

[0053] (3) Based on the number of plates N, repeat step (2) N times to determine N triangular plates; the N triangular plates are combined to obtain a triangular plate model.

[0054] The 3D modeling software can be AutoCAD, Blender, Rhino, Abaqus or Ansys software.

[0055] III. Establish a 1 / 8 plate system lattice unit model

[0056] Input the plate thickness T in the 3D modeling software so that each triangular plate is thickened by T / 2 along its positive and negative normal directions respectively to obtain a 1 / 8 plate system lattice unit model.

[0057] IV. Establish the first plate system lattice structure model UNIT

[0058] (1) Duplicate the 1 / 8 plate system lattice unit model obtained in step III, and make a mirror symmetry of the duplicated model with respect to the XOY plane in the Cartesian coordinate system to obtain a 1 / 8 plate system lattice unit symmetric model; after merging the 1 / 8 plate system lattice unit model and the 1 / 8 plate system lattice unit symmetric model, a 1 / 4 plate system lattice unit model is obtained;

[0059] (2) Duplicate the 1 / 4 plate system lattice unit model obtained in the above step, and make a mirror symmetry of the duplicated model with respect to the YOZ plane in the Cartesian coordinate system to obtain a 1 / 4 plate system lattice unit symmetric model; after merging the 1 / 4 plate system lattice unit model and the 1 / 4 plate system lattice unit symmetric model, a 1 / 2 plate system lattice unit model is obtained;

[0060] (3) Duplicate the 1 / 2 plate system lattice unit model obtained in the above step, and make a mirror symmetry of the duplicated model with respect to the ZOX plane in the Cartesian coordinate system to obtain a 1 / 2 plate system lattice unit symmetric model; after merging the 1 / 2 plate system lattice unit model and the 1 / 2 plate system lattice unit symmetric model, the first plate system lattice structure model UNIT is obtained.

[0061] V. Establish the second plate system lattice structure model BIGUNIT

[0062] (1) Duplicate 7 copies of the first plate system lattice structure model UNIT obtained in step IV, and move them along the vectors (0, 0, -2L), (0, -2L, -2L), (0, -2L, 0), (-2L, 0, 0), (-2L, 0, -2L), (-2L, -2L, -2L), (-2L, -2L, 0) respectively;

[0063] (2) After merging the first plate system lattice structure model and the models moved in the above step, the second plate system lattice structure model BIGUNIT is obtained.

[0064] VI. Establishing a Plate System Lattice Structure Reinforced Composite Material Model

[0065] (1) Establish a cube model BIGCUBIC with a side length of 2L in 3D modeling software. The 8 vertices of the cube model BIGCUBIC are (-L, -L, -L), (-L, -L, L), (-L, L, L), (-L, L, -L), (L, -L, -L), (L, -L, L), (L, L, L), and (L, L, -L) respectively.

[0066] (2) Subtract the second plate system lattice structure model BIGUNIT obtained in step five from the cube model BIGCUBIC to obtain a matrix material model.

[0067] (3) Subtract the matrix material model from the cube model BIGCUBIC to obtain a reinforcement material model.

[0068] (4) Assemble the matrix material model and the reinforcement material model to obtain a plate system lattice structure reinforced composite material model.

[0069] When establishing the first plate system lattice structure model UNIT, since the triangular surface thickens into a plate, it may cause the plate system lattice not to completely penetrate the CUBIC cube space, that is, the thickening in the positive normal direction of the plane, and the corners of the plate protrude outside the CUBIC cube. However, when thickening in the negative normal direction, the corners of the plate are still inside the CUBIC cube and do not penetrate the CUBIC cube, resulting in geometric errors. This error is only near the inner surface of the CUBIC cube. Since the second plate system lattice structure model BIGUNIT is stacked from the first plate system lattice structure model UNIT along the X, Y, and Z directions, and the cube space with a central side length of 2L is located inside the model, no geometric error will occur.

[0070] VII. Finite Element Numerical Simulation Calculation

[0071] (1) Perform mesh division on the plate system lattice structure reinforced composite material model. In the mesh division, the mesh type is 4-node tetrahedral elements, and the total number of mesh elements is not less than 500,000.

[0072] (2) Apply tensile boundary conditions to the plate system lattice structure reinforced composite material model after mesh division:

[0073] Set the value range of the maximum tensile strain E to 0.1% - 10%; set the value range of the tensile rate S to 0.0001s -1 ~0.01s -1 ;

[0074] If the stretching direction is the X direction, then the X-direction displacement of all grid nodes on the plane of X = -L is constrained to be 0, and the X-direction displacement is applied to all grid nodes on the plane of X = L, with the displacement amount being 2L×E;

[0075] If the stretching direction is the Y direction, then the Y-direction displacement of all grid nodes on the plane of Y = -L is constrained to be 0, and the Y-direction displacement is applied to all grid nodes on the plane of Y = L, with the displacement amount being 2L×E;

[0076] If the stretching direction is the Z direction, then the Z-direction displacement of all grid nodes on the plane of Z = -L is constrained to be 0, and the Z-direction displacement is applied to all grid nodes on the plane of Z = L, with the displacement amount being 2L×E.

[0077] (3) Input the material properties of the matrix material and the reinforcement material (including Young's modulus, Poisson's ratio, yield strength, and stress-strain curve in the plastic deformation section) respectively, conduct numerical simulation on the mechanical behavior during the stretching process of the plate lattice structure reinforced composite material, and obtain the Young's modulus, Poisson's ratio, strength, and elongation of the plate lattice structure composite material.

[0078] ABAQUS, ANSYS or Comsol finite element software can be used for numerical simulation.

[0079] Example 1

[0080] This example provides a method for predicting the mechanical behavior of a plate lattice reinforced composite material, and the specific steps are as follows:

[0081] I. Create a cube model CUBIC with a side length of 50 in a 3D modeling software, and the 8 vertices are respectively (0, 0, 0), (0, 0, 50), (0, 50, 50), (0, 50, 0), (50, 0, 0), (50, 0, 50), (50, 50, 50), (50, 50, 0).

[0082] II. In the 3D modeling software, select a triangular plate, input the number of plates N = 3 of the plate model; determine the plate thickness T = 2.5.

[0083] The vertex coordinates of the three triangular plates are respectively: the first plate P1 1 (0, 0, 0), P2 1 (50, 50, 50), P3 1 (50, 0, 0), the second plate P1 2 (0, 0, 0), P2 2 (50, 50, 50), P2 3 (0, 50, 0), the third plate P1 3 (0, 0, 0), P2 3 (50, 50, 50), P33 (0, 0, 50). The established triangular plate model is as Figure 1 shown.

[0084] III. Make each triangular plate thicken by 1.25 along its positive and negative normal directions respectively to obtain a 1 / 8 plate system lattice unit model, as Figure 2 shown.

[0085] IV. Mirror-symmetrically reflect the obtained 1 / 8 plate system lattice unit model in the XOY plane in the Cartesian coordinate system, merge them, then mirror-symmetrically reflect them in the YOZ plane, merge them, and then mirror-symmetrically reflect them in the ZOX plane to obtain the first plate system lattice structure model UNIT, as Figure 3 shown.

[0086] V. Copy 7 copies of the first plate system lattice structure model, and move them along the vectors (0, 0, -2L), (0, -2L, -2L), (0, -2L, 0), (-2L, 0, 0), (-2L, 0, -2L), (-2L, -2L, -2L), (-2L, -2L, 0) respectively. After merging the first plate system lattice structure model UNIT and the moved models, obtain the second plate system lattice structure model BIGUNIT, as Figure 4 shown.

[0087] VI. Establish a cube model BIGCUBIC with a side length of 2L, and its 8 vertices are (-L, -L, -L), (-L, -L, L), (-L, L, L), (-L, L, -L), (L, -L, -L), (L, -L, L), (L, L, L), (L, L, -L) respectively.

[0088] Subtract the second plate system lattice structure model BIGUNIT from the cube model BIGCUBIC to obtain the matrix material model MATRIX, as Figure 5 shown.

[0089] Subtract the matrix material model MATRIX from the cube model BIGCUBIC to obtain the reinforcement material model REINFORCEMENT, as Figure 6 shown.

[0090] Assemble the matrix material model MATRIX and the reinforcement material model REINFORCEMENT to obtain the plate system lattice structure reinforced composite material model COMPOSITE, as Figure 7 shown.

[0091] VII. Perform mesh division on the plate system lattice structure reinforced composite material model COMPOSITE. In the mesh division, the mesh type is 4-node tetrahedral elements, and the total number of mesh elements is not less than 500,000.

[0092] VIII. Input the material properties, apply boundary conditions to the plate lattice structure reinforced composite material model COMPOSITE, and use finite element software to calculate the mechanical behavior under load conditions.

[0093] (1) Use the commercial finite element software ABAQUS to input the material properties. The matrix material is 6061 aluminum (Al, Young's modulus 69 GPa, Poisson's ratio 0.33), and the reinforcement material is silicon carbide (SiC, Young's modulus 427 GPa, Poisson's ratio 0.15). The yield strength of 6061 aluminum is 267 MPa, and the stress-strain relationship is as Figure 8 shown. Silicon carbide is a purely elastic material without yield strength and plastic deformation.

[0094] (2) The tensile strain E = 1%, and the strain rate S = 0.0001 s -1 .

[0095] (3) Numerically simulate the mechanical behavior of the plate lattice structure reinforced composite material under tensile load conditions to obtain the stress distribution ( Figure 9 ) and mechanical properties ( Figure 10 ) of the lattice structure reinforced composite material.

[0096] In this embodiment, a plate lattice structure reinforced composite material model is established. The lattice structure is relatively complex. Figure 9 For the stress distribution of the matrix and reinforcement materials. It can be found that the stress distribution of the composite material is well predicted. In the aluminum matrix near the silicon carbide plate lattice, there is a certain gradient distribution. On the side close to the reinforcement phase, the matrix stress level is higher. However, its stress level (133 - 400 MPa) is much lower than that of the silicon carbide reinforcement (800 - 1600 MPa). The stress level in the reinforcement is also non-uniformly distributed. From the overall figure and each cross-sectional view, it can be seen that the stress level of the reinforcement distributed along the X direction (tensile direction) is the highest, and the stress on the silicon carbide plate plane decreases as its orientation angle increases. It can be seen that the method provided by the present invention for establishing the model can effectively predict the mechanical behavior of the plate lattice structure reinforced composite material with a complex structure.

[0097] The above-described embodiments are only a preferred solution of the present invention, but they are not intended to limit the present invention. Those of ordinary skill in the relevant technical fields can still make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all technical solutions obtained by adopting equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A method for predicting the mechanical behavior of a plate-based lattice reinforced composite material, characterized in that: The specific steps are as follows: S1: Create a cube model CUBIC with a side length of L in a 3D modeling software; S2: Based on the number of plates N, a triangular plate model is established in a 3D modeling software; S3: thickening each triangular plate in the triangular plate model to obtain a 1 / 8 plate system lattice unit model; S4: The 1 / 8 plate lattice unit model obtained in step S3 is mirror-symmetric with the XOY plane in the Cartesian coordinate system, and then mirror-symmetric with the YOZ plane after merging, and then mirror-symmetric with the ZOX plane after merging, to obtain the first plate lattice structure model; S5: doubling the first plate system lattice structure model obtained in step S4 along the X, Y, and Z axes of the Cartesian coordinate system to obtain a second plate system lattice structure model; S6: Establish a cube model BIGCUBIC with a side length of 2L; perform a volume subtraction operation in the modeling software to subtract the second plate system lattice structure model from the cube model BIGCUBIC to obtain a matrix material model; subtract the matrix material model from the cube model BIGCUBIC to obtain a reinforcement material model; S6: Assembling the matrix material model and the reinforcement material model to obtain a plate-based lattice structure reinforced composite material model; S7: Meshing the plate-based lattice structure reinforced composite model and applying tensile boundary conditions; The material properties of the matrix material and the reinforcement material are input respectively, and the mechanical behavior of the plate lattice structure reinforced composite material during the tensile process is numerically simulated to obtain the Young's modulus, Poisson's ratio, strength and elongation of the plate lattice structure composite material.

2. The method for predicting the mechanical behavior of a plate-based lattice reinforced composite material according to claim 1, characterized in that: The three-dimensional modeling software includes AutoCAD, Blender, Rhino, Abaqus or Ansys software.

3. The method for predicting the mechanical behavior of a plate-based lattice reinforced composite material according to claim 1, characterized in that: The eight vertices of the cube model CUBIC are (0, 0, 0), (0, 0, L), (0, L, L), (0, L, 0), (L, 0, 0), (L, 0, L), (L, L, L), (L, L, 0); the eight vertices of the cube model BIGCUBIC are (-L, -L, -L), (-L, -L, L), (-L, L, -L), (L, -L, -L), (L, -L, -L), (L, -L, L), (L, L, L), (L, L, -L).

4. The method for predicting mechanical behavior of plate-based lattice reinforced composite materials according to claim 1, characterized in that: The method for establishing the triangular plate model in step S2 is as follows: S201: input three vertex coordinates so that they are all located on the surface of the cube model CUBIC, and determine a triangular plate according to the three vertices; S202: Based on the number of plates N, repeat step S201 N times to determine N triangular plates; the N triangular plates are combined to obtain a triangular plate model.

5. The method for predicting mechanical behavior of plate-based lattice reinforced composite materials according to claim 1, characterized in that: In step S3, each triangular plate is thickened by T / 2 along its positive and negative normal directions respectively, so that the plate thickness is T, and a 1 / 8 plate system lattice unit model is obtained.

6. The method for predicting mechanical behavior of plate-based lattice reinforced composite materials according to claim 1, characterized in that: Step S4 is specifically as follows: S401: copying the 1 / 8 plate lattice unit model, and performing mirror symmetry with the XOY plane in a Cartesian coordinate system to obtain a 1 / 8 plate lattice unit symmetric model; merging the 1 / 8 plate lattice unit model and the 1 / 8 plate lattice unit symmetric model to obtain a 1 / 4 plate lattice unit model; S402: copying the 1 / 4 plate lattice unit model, and making a mirror symmetry with the YOZ plane in a Cartesian coordinate system to obtain a 1 / 4 plate lattice unit symmetric model; After merging the 1 / 4 plate lattice unit model and the 1 / 4 plate lattice unit symmetric model, the 1 / 2 plate lattice unit model is obtained; S403: copying the 1 / 2 plate lattice unit model, mirror-symmetric with the ZOX plane in the Cartesian coordinate system, and obtaining a 1 / 2 plate lattice unit symmetric model; merging the 1 / 2 plate lattice unit model and the 1 / 2 plate lattice unit symmetric model to obtain a first plate lattice structure model.

7. The method for predicting mechanical behavior of plate-based lattice reinforced composite materials according to claim 1, characterized in that: Step S5 is specifically as follows: S501: Copy 7 copies of the first plate system lattice structure model, and move them along the vectors (0, 0, -2L), (0, -2L, -2L), (0, -2L, 0), (-2L, 0, 0), (-2L, 0, -2L), (-2L, -2L, -2L), (-2L, -2L, 0), respectively; S502: The first plate-based lattice structure model and the model moved in step S501 are merged to obtain a second plate-based lattice structure model.

8. The method for predicting mechanical behavior of plate-based lattice reinforced composite materials according to claim 1, characterized in that: The mesh type in the mesh division in step S7 is a 4-node tetrahedron unit, and the total number of mesh units is not less than 500,000.

9. The method for predicting mechanical behavior of plate-based lattice reinforced composite materials according to claim 1, characterized in that: The stretching boundary conditions in step S7 are set as follows: S701: Set the maximum tensile strain E to a value range of 0.1% to 10%; set the tensile rate S to a value range of 0.0001s -1 ~0.01s -1 ; S702: If the stretching direction is the X direction, the X-direction displacement of all mesh nodes in the X=-L plane is constrained to be 0, and a displacement in the X direction is applied to all mesh nodes in the X=L plane, and the displacement amount is 2L×E; if the stretching direction is the Y direction, the Y-direction displacement of all mesh nodes in the Y=-L plane is constrained to be 0, and a displacement in the Y direction is applied to all mesh nodes in the Y=L plane, and the displacement amount is 2L×E; if the stretching direction is the Z direction, the Z-direction displacement of all mesh nodes in the Z=-L plane is constrained to be 0, and a displacement in the Z direction is applied to all mesh nodes in the Z=L plane, and the displacement amount is 2L×E.

10. The method for predicting mechanical behavior of plate-based lattice reinforced composite materials according to claim 1, characterized in that: In step S7, numerical simulation is performed using ABAQUS, ANSYS or Comsol finite element software.

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