A method for predicting thermal residual stress of a lattice structure reinforced composite material

Abstract

The application discloses a kind of lattice structure reinforced composite material thermal residual stress prediction method, belongs to lattice structure lattice unit model design field.Specific as follows:1) establish tetrahedron model and establish basic beam model;2) basic beam model is merged after rotation, and the intersection part with tetrahedron model is 1 / 48 lattice unit model;3) sequentially obtain 1 / 24 lattice unit model, 1 / 8 lattice unit model and complete lattice structure model;4) establish cubic model;Subtract lattice structure model from cubic model, obtain matrix model;5) obtain lattice structure reinforced composite material geometric model;6) the thermal mismatch behavior of lattice structure reinforced composite material geometric model during cooling process is simulated numerically, and the thermal residual stress distribution of lattice structure reinforced composite material is obtained.The method is simple to operate, and the lattice structure model constructed is rich, and the simulation precision is high.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of lattice structure lattice unit model design, and particularly relates to a lattice structure reinforced composite material thermal residual stress prediction method. BACKGROUND

[0002] The thermal residual stress of the lattice structure reinforced composite material is a problem that is very concerned in engineering design. The geometric shape of the lattice structure has an important influence on the thermal residual stress distribution. The load transmission and two-phase deformation are qualitatively reflected by using the experimental measurement method, however, it is difficult to systematically and comprehensively measure the influence of different shapes of the lattice structure on the stress and strain distribution and the residual stress distribution of the system through the experimental method.

[0003] In recent years, the finite element simulation technology has been more and more applied in the simulation of the mechanical behavior of the lattice structure, and relatively accurate performance prediction results have been achieved. A new type of lattice structure lattice unit modeling method combined with the finite element simulation technology is expected to realize the thermal shrinkage behavior and high-throughput calculation of the lattice structure of different shapes, reveal the relationship between the lattice unit shape and the thermal residual stress distribution of the lattice structure reinforced composite material, meet the research work requirements, and the calculation results are expected to guide the research and development of new structures in engineering applications. SUMMARY

[0004] The application aims at the status of the difficulty in modeling the lattice structure lattice unit shape in the prior art, and provides a lattice structure reinforced composite material thermal residual stress prediction method. The method provided by the application can create lattice structures of various shapes. With the help of the finite element simulation technology, the thermal shrinkage behavior of the lattice structure reinforced composite material is predicted, and the thermal residual stress of the lattice structure is calculated.

[0005] The specific technical scheme adopted by the application is as follows:

[0006] The application provides a lattice structure reinforced composite material thermal residual stress prediction method, and the specific steps are as follows:

[0007] S1: create a tetrahedron model OABC in a three-dimensional drawing software, and the vertex positions of the tetrahedron model OABC are O(0, 0, 0), A(L, L, L), B(0, 0, L), and C(0, L, L) respectively;

[0008] S2: input the number of beams N and the cross-sectional shape parameters in the three-dimensional drawing software, create a basic beam model, and determine the position of the beam;

[0009] S3: according to the number N of beams in the basic beam model in step S2, copy N basic beam models; each basic beam model is rotated and combined into a solid model; the intersection part of the solid model and the tetrahedron model created in step S1 is a 1 / 48 lattice unit model;

[0010] S4: mirror symmetry of the 1 / 48 lattice unit model obtained in step S3 in the ACO plane to obtain a 1 / 48 lattice unit mirror symmetry model; and combining the 1 / 48 lattice unit model and the 1 / 48 lattice unit mirror symmetry model to obtain a 1 / 24 lattice unit model;

[0011] S5: duplicating the 1 / 24 lattice unit model obtained in step S4 twice, rotating them respectively, and then combining them to obtain a 1 / 8 lattice unit model;

[0012] S6: mirror symmetry of the 1 / 8 lattice unit model obtained in step S5 in the XOY plane in the Cartesian coordinate system, then mirror symmetry in the YOZ plane, and then mirror symmetry in the ZOX plane to obtain a complete lattice structure model;

[0013] S7: establishing a cubic model with a side length of 2L; and performing volume subtraction in the modeling software to subtract the lattice structure model from the cubic model to obtain a matrix model;

[0014] S8: assembling the matrix model obtained in step S7 and the lattice structure model in step S6 to obtain a lattice structure reinforced composite material geometric model;

[0015] S9: meshing the lattice structure reinforced composite material geometric model obtained in step S8, applying a cooling boundary condition, inputting the material properties of the matrix model and the lattice structure model respectively; and numerically simulating the thermal mismatch behavior of the lattice structure reinforced composite material geometric model in the cooling process to obtain the thermal residual stress distribution of the lattice structure reinforced composite material.

[0016] As a preferred, the three-dimensional drawing software is AutoCAD, Blender, Rhino or Abaqus.

[0017] As a preferred, in step S2, if the cross-sectional shape parameter is a circle, the cross-sectional radius is input; if the cross-sectional shape parameter is an annulus, the inner diameter and the outer diameter of the annulus are input; if the cross-sectional shape parameter is a polygon, the number of sides and the circumscribed circle radius of the polygon are input.

[0018] As a preferred, in step S2, the beam position is determined as follows: it is specified that the starting point of each beam in the base beam model is at any vertex of the tetrahedral model OABC, the ending point of the beam is on any side of the plane opposite to the vertex, and the offset value of the beam orientation is in the range of [0, 1] to determine the position of the beam.

[0019] Preferably, the rotation mode of each base beam model in step S3 is as follows: a direction vector Vn of the beam is obtained according to the starting point and the ending point of the beam, and the direction vector Vn is unitized to obtain Vn'; a rotation axis RotAxis = Vn' + (0, 0, 1) is determined; and the centroid of the beam is taken as a rotation center, and the beam is rotated 180° around the rotation axis RotAxis vector.

[0020] Preferably, 1 / 24 first lattice unit models and 1 / 24 second lattice unit models are obtained after copying in step S5, respectively; the 1 / 24 first lattice unit models are rotated 120° clockwise around the (1, 1, 1) vector, the 1 / 24 second lattice unit models are rotated 120° counterclockwise around the (1, 1, 1) vector, and the two rotated 1 / 24 lattice unit models are combined to obtain a 1 / 8 lattice unit model.

[0021] Preferably, in step S7, the coordinates of the vertices of the cube model 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.

[0022] Preferably, in the mesh division in step S9, the mesh type is a 4-node tetrahedral element, and the total number of mesh elements is not less than 500,000.

[0023] Preferably, in the cooling boundary condition setting in step S9, the high-temperature temperature T1 is not greater than 1600℃, the low-temperature temperature T0 is not less than -100℃, and the cooling rate ΔT is 2-200℃.

[0024] Preferably, in step S9, the numerical simulation is performed by using finite element software ABAQUS, ANSYS or Comsol software.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] (1) The method provided by the present application can generate lattice structures of various shapes, the shape of the lattice structure is controlled by flexibly setting the beam position parameters, the established lattice structure model has a rich shape, is close to the real lattice structure geometric model in industrial production, and has wide applicability.

[0027] (2) The modeling process in the present application is convenient and simple to operate, only a small number of parameters such as all the faces, vertices and directions of the tetrahedron need to be controlled, and the user can operate conveniently.

[0028] (3) By calculating the thermal shrinkage behavior of the lattice structure, the distribution of the internal stress and thermal shrinkage strain involved can be revealed, which has important academic significance, and can also provide effective guidance for the structural design of industrial materials. Attached Figure Description

[0029] Figure 1 The 1 / 48 lattice unit model established in Examples 1 to 3;

[0030] Figure 2 The 1 / 24 lattice unit model established in Examples 1 to 3;

[0031] Figure 3 The 1 / 8 lattice unit model established in Examples 1 to 3;

[0032] Figure 4 The lattice unit model established in Examples 1 to 3;

[0033] Figure 5 The thermal residual stress simulation cloud map is for the geometric model of the lattice structure reinforced composite material established in Examples 1 to 3. Detailed Implementation

[0034] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.

[0035] This invention provides a method for predicting the thermal residual stress of lattice-structured reinforced composite materials. The specific steps of the operation are as follows:

[0036] 1. Create a tetrahedral model.

[0037] Create a tetrahedral model OABC in a 3D modeling software. The vertex positions of the tetrahedral model OABC are: O(0, 0, 0), A(L, L, L), B(0, 0, L), and C(0, L, L). The BOC plane of the tetrahedral model OABC is denoted as 0, the CAB plane as 1, the OBA plane as 2, and the ACO plane as 3.

[0038] 2. Create the foundation beam model.

[0039] In the 3D modeling software, input the number of beams N and the cross-sectional shape parameters to create the foundation beam model. If the cross-sectional shape parameter is circular, input the cross-sectional radius; if the cross-sectional shape parameter is annular, input the inner and outer diameters of the annulus; if the cross-sectional shape parameter is polygonal, input the number of sides of the polygon and the radius of its circumcircle.

[0040] 3. Determine the location of the beam.

[0041] The starting point of each beam in the base beam model is at any vertex of the tetrahedron model OABC, and the ending point is on any edge of the plane opposite to the vertex. If the starting point is at A of the tetrahedron model OABC, the ending point is on the edge BC, BO or CO of the plane BOC opposite to A (so that the beam is in the plane ACO); if the starting point is at B of the tetrahedron model OABC, the ending point is on the edge AC, CO or AO of the plane ACO opposite to B; and so on.

[0042] The offset of the beam orientation is in the range of [0, 1], and the position of the beam is determined.

[0043] Four, obtain a 1 / 48 lattice unit model.

[0044] (1) According to the number N of beams in the base beam model, copy N base beam models.

[0045] (2) Obtain the direction vector Vn of the beam according to the starting point and the ending point of the beam, and unitize the direction vector Vn to obtain Vn', so that the vector length is 1.

[0046] (3) Determine the rotation axis RotAxis:

[0047] RotAxis = Vn' + (0, 0, 1);

[0048] (4) Take the centroid of the beam as the rotation center, and rotate it by 180° around the rotation axis RotAxis vector.

[0049] (5) After rotating the N base beam models, combine them into a solid model GEO; the intersection part of the solid model GEO and the tetrahedron model created in step one is a 1 / 48 lattice unit model.

[0050] Five, obtain a 1 / 24 lattice unit model.

[0051] Copy the 1 / 48 lattice unit model obtained in step four, and obtain a 1 / 48 lattice unit mirror symmetry model by mirror symmetry in the plane ACO; combine the 1 / 48 lattice unit model and the 1 / 48 lattice unit mirror symmetry model to obtain a 1 / 24 lattice unit model.

[0052] Six, obtain a 1 / 8 lattice unit model.

[0053] (1) Copy the 1 / 24 lattice unit model obtained in step five twice, and mark them as 1 / 24 first lattice unit model and 1 / 24 second lattice unit model respectively.

[0054] (2) Rotate the 1 / 24 first lattice unit model clockwise by 120° around the (1, 1, 1) vector, and rotate the 1 / 24 second lattice unit model counterclockwise by 120° around the (1, 1, 1) vector.

[0055] (3) Merge the two rotated 1 / 24 lattice unit models to obtain a 1 / 8 lattice unit model.

[0056] Seven, obtain a complete lattice structure model.

[0057] (1) Copy the 1 / 8 lattice unit model obtained in step six, and mirror it in the XOY plane in the Cartesian coordinate system to obtain Model_1_8_XOY model. Merge the 1 / 8 lattice unit model and the Model_1_8_XOY model to obtain Model_1_8_1 model.

[0058] (2) Copy the Model_1_8_1 model, and mirror it in the YOZ plane in the Cartesian coordinate system to obtain Model_1_8_1_YOZ model. Merge the Model_1_8_1 model and the Model_1_8_1_YOZ model to obtain Model_1_8_2 model.

[0059] (3) Copy the Model_1_8_2 model, and mirror it in the ZOX plane in the Cartesian coordinate system to obtain Model_1_8_2_ZOX model. Merge the Model_1_8_2 model and the Model_1_8_2_ZOX model to obtain a complete lattice structure model.

[0060] Eight, establish a cubic model.

[0061] Establish a cubic model CUBIC with a side length of 2L. The coordinates of the vertices of the cubic model CUBIC 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).

[0062] Nine, subtractive operation.

[0063] In the modeling software, take the cubic model CUBIC established in step eight as the minuend, and take the lattice structure model obtained in step seven as the subtrahend. Subtract the lattice structure model from the cubic model to obtain a matrix model.

[0064] Ten, obtain a lattice structure reinforced composite material geometric model.

[0065] Assemble the matrix model obtained in step nine and the lattice structure model in step seven to obtain a lattice structure reinforced composite material geometric model.

[0066] Eleven, numerical simulation.

[0067] Grid the lattice structure reinforced composite material geometry model obtained in step ten, the grid type in the grid division is 4-node tetrahedral element, and the total number of grid elements is not less than 500000. A cooling boundary condition is applied: the high-temperature temperature T1 is not greater than 1600 DEG C, the low-temperature temperature T0 is not less than-100 DEG C, and the cooling rate AT is 2-200 DEG C.

[0068] The material properties of the matrix model and the lattice structure model are input respectively; the thermal mismatch behavior of the lattice structure reinforced composite material geometry model in the cooling process is simulated numerically, and the thermal residual stress distribution of the lattice structure reinforced composite material is obtained.

[0069] In the application, the three-dimensional drawing software is AutoCAD, Blender, Rhino or Abaqus. The numerical simulation is carried out by using finite element software ABAQUS, ANSYS or Comsol software.

[0070] Example 1

[0071] I. Create a tetrahedron OABC with the shortest edge length L of the geometric parameter; the vertex positions of the tetrahedron model OABC are respectively: O(0, 0, 0), A(L, L, L), B(0, 0, L), and C(0, L, L).

[0072] II. Input the number of beams N=2, the cross-sectional shape parameter is a circle with a radius of 5, and create a basic beam model.

[0073] III. Determine that the plane parameter of the first beam is 0, the node number of the beam is 0, and the starting point PO1 of the first beam is (0, 0, L). The offset of the beam orientation is 0.75, so the starting point PE1 of the first beam is (0, 0.75L, 0.75L); the plane parameter of the second beam is determined to be 1, the node number of the beam is 1, and the starting point PO1' of the second beam is (L, L, L). The offset of the beam orientation is 0, so the terminal point PE1' of the second beam is (0, 0, L).

[0074] IV. According to the number of two beams, copy 2 basic beam models, and perform the following operations on the two basic beam models respectively:

[0075] (1) Obtain the direction vector Vn of the beam according to the starting point and the terminal point of the beam, and unitize the direction vector Vn to obtain Vn', so that the vector length is 1.

[0076] (2) Determine the rotation axis RotAxis:

[0077] RotAxis = Vn' + (0, 0, 1);

[0078] (3) Take the centroid of the beam as the rotation center, and rotate it 180° around the rotation axis RotAxis vector.

[0079] (2) After rotating the two basic beam models, merge them into a solid model GEO; the intersection part of the solid model GEO and the tetrahedron model OABC created in step one is a 1 / 48 lattice unit model, as shown in Figure 1 (a).

[0080] Five, copy the above 1 / 48 lattice unit model, and mirror symmetry with the ACO plane to get a 1 / 48 lattice unit mirror symmetry model; merge the 1 / 48 lattice unit model and the 1 / 48 lattice unit mirror symmetry model to get a 1 / 24 lattice unit model, as shown in Figure 2 (a).

[0081] Six, copy two copies of the above 1 / 24 lattice unit model, and mark them as 1 / 24 first lattice unit model and 1 / 24 second lattice unit model respectively. Rotate the 1 / 24 first lattice unit model clockwise around the (1, 1, 1) vector by 120°, and rotate the 1 / 24 second lattice unit model counterclockwise around the (1, 1, 1) vector by 120°. Merge the two rotated 1 / 24 lattice unit models to get a 1 / 8 lattice unit model, as shown in Figure 3 (a).

[0082] Seven, get the complete lattice structure model.

[0083] (1) Copy one copy of the above 1 / 8 lattice unit model, and mirror symmetry with the XOY plane in the Cartesian coordinate system to get Model_1_8_XOY model; merge the 1 / 8 lattice unit model and Model_1_8_XOY model to get Model_1_8_1 model;

[0084] (2) Copy one copy of Model_1_8_1 model, and mirror symmetry with the YOZ plane in the Cartesian coordinate system to get Model_1_8_1_YOZ model; merge Model_1_8_1 model and Model_1_8_1_YOZ model to get Model_1_8_2 model;

[0085] (3) Copy one copy of Model_1_8_2 model, and mirror symmetry with the ZOX plane in the Cartesian coordinate system to get Model_1_8_2_ZOX model; merge Model_1_8_2 model and Model_1_8_2_ZOX model to get the complete lattice structure model.

[0086] Eight, a cubic model CUBIC with a side length of 2L is established; the coordinates of the vertices of the cubic model CUBIC 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.

[0087] Nine, a body subtraction operation is performed in the modeling software, the cubic model CUBIC is taken as a subtracted object, and the lattice structure model is taken as a subtracted object, so that the lattice structure model is subtracted from the cubic model to obtain a matrix model.

[0088] Ten, the matrix model and the lattice structure model are assembled to obtain a geometric model of the lattice structure reinforced composite material, as shown in Figure 4 (a).

[0089] Example 2

[0090] The remaining steps of this example are consistent with those of Example 1, except that the offset amounts of the two beams are different: the plane parameters of the first beam are determined to be 0, the node numbers of the beam are determined to be 0, and the starting point PO2 of the first beam is (0, 0, L). The offset amount of the beam orientation is 1, so the end point PE2 of the first beam is (0, L, L); the plane parameters of the second beam are determined to be 1, the node numbers of the beam are determined to be 1, and the starting point PO2' of the second beam is (L, L, L). The offset amount of the beam orientation is 0, so the end point PE2' of the second beam is (0, 0, L).

[0091] The 1 / 48 lattice unit model established in this example is shown in Figure 1 (b). The 1 / 24 lattice unit model is shown in Figure 2 (b). The 1 / 8 lattice unit model is shown in Figure 3 (b). The geometric model of the lattice structure reinforced composite material finally established is shown in Figure 4 (b).

[0092] Example 3

[0093] The remaining steps of this example are consistent with those of Example 1, except that the offset amounts of the two beams are different: the plane parameters of the first beam are determined to be 0, the node numbers of the beam are determined to be 0, and the starting point PO3 of the first beam is (0, 0, L). The offset amount of the beam orientation is 1, so the end point PE3 of the first beam is (0, L, L); the plane parameters of the second beam are determined to be 1, the node numbers of the beam are determined to be 1, and the starting point PO3' of the second beam is (L, L, L). The offset amount of the beam orientation is 1, so the end point PE3' of the second beam is (0, L, L).

[0094] The 1 / 48 dot array unit model established in this embodiment is shown in Fig. 1 (c). The 1 / 24 dot array unit model is shown in Fig. 2 (c). The 1 / 8 dot array unit model is shown in Fig. 3 (c). The final dot array structure reinforced composite material geometric model is shown in Fig. 4 (c). Figure 1 The 1 / 48 dot array unit model established in this embodiment is shown in Fig. 1 (c). The 1 / 24 dot array unit model is shown in Fig. 2 (c). The 1 / 8 dot array unit model is shown in Fig. 3 (c). The final dot array structure reinforced composite material geometric model is shown in Fig. 4 (c). Figure 2 The 1 / 48 dot array unit model established in this embodiment is shown in Fig. 1 (c). The 1 / 24 dot array unit model is shown in Fig. 2 (c). The 1 / 8 dot array unit model is shown in Fig. 3 (c). The final dot array structure reinforced composite material geometric model is shown in Fig. 4 (c). Figure 3 The 1 / 48 dot array unit model established in this embodiment is shown in Fig. 1 (c). The 1 / 24 dot array unit model is shown in Fig. 2 (c). The 1 / 8 dot array unit model is shown in Fig. 3 (c). The final dot array structure reinforced composite material geometric model is shown in Fig. 4 (c). Figure 4 The 1 / 48 dot array unit model established in this embodiment is shown in Fig. 1 (c). The 1 / 24 dot array unit model is shown in Fig. 2 (c). The 1 / 8 dot array unit model is shown in Fig. 3 (c). The final dot array structure reinforced composite material geometric model is shown in Fig. 4 (c).

[0095] Next, the dot array structure reinforced composite material geometric models established in Examples 1-3 are subjected to thermal residual stress distribution prediction, as follows:

[0096] (1) The dot array structure reinforced composite material geometric models are respectively divided into three-dimensional meshes, and the mesh type is 4-node 4-face mesh, and the number of meshes is about 880000.

[0097] (2) The cooling boundary condition is set, the high temperature T1=500℃, the low temperature T0=20℃, and the cooling rate ΔT=10℃.

[0098] (3) The commercial finite element software ABAQUS is used, and the material properties are input: the material of the matrix model is pure aluminum (Al), and the material of the dot array structure model is silicon carbide (SiC). The Poisson's ratio is not sensitive to temperature, and the aluminum is 0.33 and the silicon carbide is 0.17. The Young's modulus (E Al , unit GPa) of aluminum changes with temperature (T) as follows:

[0099] E Al =68.93+0.017T-3.97×10 -4 T 2 +4.28×10 -7 T 3

[0100] The thermal expansion coefficient (α Al , unit 10 -6 / K) of aluminum changes with temperature (T) as follows:

[0101] α Al =(21.98+0.017T-1.89×10 -5 T 2 +5.30×10 -9 T 3 )

[0102] The Young's modulus (E SiC , unit GPa) of silicon carbide changes with temperature (T) as follows:

[0103] E Al =427.48-0.025T+1.58×10 -6 T 2-2.00 x 10 -9 T 3

[0104] The thermal expansion coefficient (a SiC , in 10 -6 / K) of silicon carbide as a function of temperature (T) is:

[0105] a Al =(3.07+0.006T-5.85 x 10 -6 T 2 +2.07 x 10 -9 T 3

[0106] The thermal mismatch behavior of lattice-reinforced composites during cooling is simulated numerically to obtain the thermal residual stress distribution of the lattice-reinforced composites.

[0107] Three geometric models of lattice-reinforced composites are established in this example. The lattice structure is relatively complex. Figure 5 The residual stress distribution of the matrix is shown in the cross-sectional view at X=0 (Figures (a), (c), (e)) and X=50 (Figures (b), (d), (f)). It can be found that the thermal residual stress distribution of the composite is well predicted. There is a high thermal residual stress in the aluminum matrix near the silicon carbide lattice. However, by comparing the residual stress cross-sectional view, it can be found that in the first lattice structure, there is a very low stress zone and a very high stress strip pattern in the aluminum matrix far from the silicon carbide. The second and third models do not have this feature, and there is only a low stress zone in the matrix far from the silicon carbide. It can be seen that the method provided by the present application can effectively predict the thermal residual stress distribution of lattice-reinforced composites with complex structure.

[0108] The above-described embodiments are only a preferred scheme of the present application, and are not intended to limit the present application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, any technical solutions obtained by equivalent replacement or equivalent transformation shall fall within the protection scope of the present application.​

Claims

1. A method of predicting thermal residual stresses in a lattice structure reinforced composite material, characterized in that, The specific steps are as follows: S1: create a tetrahedron model OABC in a three-dimensional drawing software, and the vertex positions of the tetrahedron model OABC are respectively: O (0, 0, 0), A (L, L, L), B (0, 0, L), and C (0, L, L); S2: input the number of beams N and the cross-sectional shape parameters in the three-dimensional drawing software to create a basic beam model; and the position of the beam is determined; S3: according to the number N of beams in the basic beam model in step S2, copy N basic beam models; each basic beam model is rotated and combined into a solid model; and the intersecting part of the solid model and the tetrahedron model created in step S1 is a 1 / 48 lattice unit model; S4: mirror symmetry is performed on the 1 / 48 lattice unit model obtained in step S3 with the ACO plane as the mirror plane to obtain a 1 / 48 lattice unit mirror symmetry model; and the 1 / 48 lattice unit model and the 1 / 48 lattice unit mirror symmetry model are combined to obtain a 1 / 24 lattice unit model; S5: copy two copies of the 1 / 24 lattice unit model obtained in step S4, and combine them after being rotated respectively to obtain a 1 / 8 lattice unit model; S6: mirror symmetry is performed on the 1 / 8 lattice unit model obtained in step S5 with the XOY plane as the mirror plane, and then mirror symmetry is performed with the YOZ plane as the mirror plane, and then mirror symmetry is performed with the ZOX plane as the mirror plane to obtain a complete lattice structure model; S7: a cube model with a side length of 2L is established; and a body subtraction operation is performed in the modeling software to subtract the lattice structure model from the cube model to obtain a matrix model; S8: the matrix model obtained in step S7 and the lattice structure model in step S6 are assembled to obtain a lattice structure reinforced composite material geometric model; S9: the lattice structure reinforced composite material geometric model obtained in step S8 is meshed, a cooling boundary condition is applied, and the material properties of the matrix model and the lattice structure model are input respectively; The thermal mismatch behavior of the lattice structure reinforced composite material geometric model during cooling is numerically simulated to obtain the thermal residual stress distribution of the lattice structure reinforced composite material.

2. The method of claim 1, wherein the method further comprises: The three-dimensional drawing software is AutoCAD, Blender, Rhino or Abaqus.

3. The method of claim 1, wherein the method further comprises: In step S2, if the cross-sectional shape parameter is a circle, the cross-sectional radius is input; if the cross-sectional shape parameter is a ring, the inner diameter and the outer diameter of the ring are input; and if the cross-sectional shape parameter is a polygon, the number of sides and the circumscribed circle radius of the polygon are input.

4. The method of claim 1, wherein the method further comprises: In step S2, the position of the beam is determined as follows: it is specified that the starting point of each beam in the basic beam model is at any one vertex of the tetrahedron model OABC, the ending point of the beam is on any one side of the plane opposite to the vertex, and the offset of the beam orientation is in the range of [0, 1], and the position of the beam is determined.

5. The method of claim 1, wherein the method further comprises: In step S3, the rotation mode of each basic beam model is as follows: the direction vector Vn of the beam is obtained according to the starting point and the ending point of the beam, and the direction vector Vn is unitized to obtain Vn'; the rotation axis RotAxis is determined as Vn'+(0, 0, 1); and the beam center is taken as the rotation center, and the beam is rotated 180° around the rotation axis RotAxis vector.

6. The method of claim 1, wherein the method further comprises: The 1 / 24 first dot array unit model is rotated clockwise by 120° around the (1, 1, 1) vector, and the 1 / 24 second dot array unit model is rotated counterclockwise by 120° around the (1, 1, 1) vector, and the two rotated 1 / 24 dot array unit models are combined to obtain a 1 / 8 dot array unit model.

7. The method of claim 1, wherein the method further comprises: In step S7, the coordinates of the vertices of the cubic model 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.

8. The method of claim 1, wherein the method further comprises: In step S9, the grid type in the grid division is a 4-node tetrahedral element, and the total number of grid elements is not less than 500,000.

9. The method of claim 1, wherein the method further comprises: In step S9, the cooling boundary condition is set as follows: the high-temperature temperature T1 is not greater than 1600℃, the low-temperature temperature T0 is not less than -100℃, and the cooling rate ΔT is 2-200℃.

10. The method of claim 1, wherein the method is used to predict thermal residual stresses in a lattice-reinforced composite material. In step S9, numerical simulation is performed by using finite element software ABAQUS, ANSYS or Comsol software.

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