2.5-dimensional woven composite multiscale analysis method considering micro failure mechanism

Abstract

The application discloses a 2.5D woven composite material multi-scale analysis method considering micro failure mechanism, and comprises the following steps: establishing a 2.5D woven composite material microcell finite element model, giving component material performance to the microcell finite element model and applying a periodic boundary condition, obtaining equivalent elastic parameters of the microcell model and strain-stress amplification factors of each element, utilizing a K-means clustering algorithm, taking the strain-stress amplification factors of each element in the microcell model as characteristic data, clustering and reducing the order of the microcell model, taking the average value of the strain-stress amplification factors of the elements in each cluster as the strain-stress amplification factor of the cluster, giving component material performance to the microcell finite element model and applying a periodic boundary condition, and the like. The application is based on the micro failure theory and analyzes the damage mechanism of fiber filaments and the matrix in the composite material damage process from the microcell model scale.

Description

Technical Field

[0001] This invention relates to the field of mechanical property evaluation technology for woven composite materials, specifically a 2.5-dimensional multi-scale analysis method for woven composite materials that considers microscopic failure mechanisms. Background Technology

[0002] Carbon fiber reinforced composites are widely used in aerospace, civil engineering, and automotive fields due to their excellent mechanical properties and designability. Among them, 2.5D woven composites are three-dimensional woven composites formed by the interlocking of warp and weft yarns. They not only overcome the shortcomings of traditional laminated composites, such as easy delamination and poor damage resistance, but also overcome the complex manufacturing process of general three-dimensional woven composites. Therefore, the characterization of the mechanical properties of 2.5D woven composites and the prediction of the mechanical behavior of composite structures have become hot topics in composite material research.

[0003] Currently, the commonly used method for predicting the performance of 2.5D woven composite materials is the hierarchical multi-scale analysis method. The information transmission is unidirectional. Although it can predict the strength of composite materials, it cannot fully reflect the influence of microstructure on the damage initiation and propagation process of the model. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] Therefore, the purpose of this invention is to provide a multi-scale analysis method for 2.5D woven composite materials that considers microscopic failure mechanisms. Based on microscopic failure theory, the method analyzes the damage mechanism of fiber filaments and matrix during composite material damage at the microscopic model scale.

[0006] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0007] A multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms includes:

[0008] S1. Establish finite element models of 2.5D woven composite materials at the mesoscopic and microscopic unit cell levels;

[0009] S2. Assign component material properties and apply periodic boundary conditions to the micro-unit cell finite element model to obtain the equivalent elastic parameters of the micro-unit cell model and the strain-stress amplification factor of each element;

[0010] S3. Using the K-means clustering algorithm, the strain-stress amplification factor of each unit in the micro-cell model is used as the feature data to cluster and reduce the order of the micro-cell model. The average strain-stress amplification factor of each unit in each cluster is used as the strain-stress amplification factor of the cluster.

[0011] S4. Assign component material properties and apply periodic boundary conditions to the mesoscopic unit cell finite element model to obtain the average stress and average strain of the mesoscopic model, as well as the strain vector of the fiber bundle element and the stress vector of the matrix element.

[0012] S5. Based on the stress vector of the matrix element in step S4, and combined with the damage initiation criterion and damage propagation model, obtain the elastic parameters of the matrix material after damage.

[0013] S6. Based on the strain vector of the fiber bundle unit in step S4, and combined with the strain-stress amplification factor of the micro-cluster in step S3, calculate the stress vector of the cluster in the micro-model.

[0014] S7. Based on the stress vectors of each cluster in the microscopic model in step S6, and combined with different damage initiation criteria and damage propagation models, obtain the stiffness matrix after damage of different clusters. Combine with the microscopic equivalent elastic parameter prediction model, obtain the equivalent elastic parameters of the fiber bundle unit after damage.

[0015] S8. Determine whether the model has ultimately failed. If it has failed, plot the stress-strain curve to obtain the strength of the 2.5D woven composite material. If it has not failed, repeat steps S2 to S7.

[0016] As a preferred embodiment of the multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms described in this invention, the steps in step S2 for obtaining the equivalent elastic parameters of the microscopic unit cell model and the strain-stress amplification factor of each element are as follows:

[0017] S201. Assign material properties to the micro-unit cell finite element model, including fiber filaments and matrix;

[0018] S202. Apply periodic boundary conditions to the microscopic unit cell finite element model as follows:

[0019]

[0020]

[0021] Where j+ and j- represent opposite faces. This represents the tensile / compressive deformation caused by a unit cell being loaded in the three principal directions. Corresponding to shear deformation in the three principal directions, The average strain of the microscopic unit cell model. The distance between corresponding points on opposing boundary surfaces;

[0022] S203. The equivalent elastic parameters of the microscopic unit cell model are calculated using the volume averaging method, as follows:

[0023]

[0024]

[0025]

[0026] Where N f N represents the total number of fiber units. m σ represents the total number of matrix elements. ijk Let ε be the stress of the k-th element in the ij direction. ijk V represents the strain of the k-th element in the ij direction. k Let V be the volume of the k-th unit, and V be the total volume of the unit cell;

[0027] S204. Obtain the strain-stress amplification factor of the microscopic unit cell model element. The strain-stress amplification factor characterizes the response relationship between the external strain and internal stress of each element in the microscopic model. The method is as follows:

[0028]

[0029] Where {σ} represents the micro-stress on a single element within the unit cell model. This represents the strain load applied externally to the unit cell model, and [A] represents the strain-stress amplification factor.

[0030] As a preferred embodiment of the 2.5D woven composite material multi-scale analysis method considering microscopic failure mechanisms described in this invention, in step S3, the fiber monofilament units and matrix units in the microscopic unit cell model are clustered separately, into fiber clusters and matrix clusters.

[0031] As a preferred embodiment of the 2.5D woven composite material multi-scale analysis method considering microscopic failure mechanisms described in this invention, the specific steps in step S4 for obtaining the strain vector of the fiber bundle element and the stress vector of the matrix element in the mesoscopic model include:

[0032] S401. Assign material properties to the micro-unit finite element model, including fiber bundles and matrix;

[0033] S402. Apply periodic boundary conditions to the microscopic unit cell model;

[0034] S403. Obtain the stress vector and strain vector of each element, and calculate the average stress and average strain of the mesoscopic unit cell model.

[0035] S404. Obtain the strain vector of the fiber bundle element and the stress vector of the matrix element in the mesoscopic model, respectively.

[0036] As a preferred embodiment of the 2.5D woven composite material multi-scale analysis method considering microscopic failure mechanisms described in this invention, in step S5, the damage initiation criterion is the von Mises failure criterion, specifically as follows:

[0037]

[0038]

[0039]

[0040] Where T m and C m These are the tensile strength and compressive strength of the matrix material, σ ij This represents the stress vector of the matrix.

[0041] As a preferred embodiment of the multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms described in this invention, the specific steps in step S7 for obtaining the equivalent elastic parameters of the damaged fiber bundle unit include:

[0042] S701. Based on the stress vector of the cluster in the micro model calculated in step S6, the damage initiation criterion and damage propagation model described in step S5 are used for the matrix cluster to obtain the elastic parameters after damage of each matrix cluster, and then the elastic parameters after damage of the whole matrix are obtained by volume averaging.

[0043] S702. Based on the stress vectors of the clusters in the microscopic model calculated in step S6, the maximum stress criterion is adopted for fiber clustering, and the corresponding damage variable is set to 0.999, as follows:

[0044]

[0045]

[0046]

[0047] in T is used to withstand stress in the fiber direction. f and C f These are the tensile and compressive strengths of the fiber, E f The elastic modulus before fiber damage. The elastic modulus after fiber damage is determined by the maximum damage state among all fiber clusters.

[0048] S703. Based on the above steps S701 and S702, the elastic parameters of the matrix material and fiber material after damage in the microscopic model are obtained. Then, combined with the Chamis equivalent elastic parameter prediction model, the elastic performance parameters of the fiber bundle are obtained as follows:

[0049] E 11 =V f E f11 +V m E m ;

[0050]

[0051]

[0052]

[0053] v 12 =v 13 =v m +V f (v f12 -v m );

[0054]

[0055] As a preferred embodiment of the 2.5D woven composite material multi-scale analysis method considering microscopic failure mechanisms described in this invention, the final failure criterion of the model in step S8 is specifically determined when the stress borne by the material decreases with the increase of strain, indicating that the model has failed.

[0056] As a preferred embodiment of the 2.5D woven composite material multi-scale analysis method considering microscopic failure mechanisms described in this invention, in step S8, the stress-strain curve is plotted by reading the average stress and average strain of the mesoscopic unit cell model calculated in step S4 of each cycle step from step S2 to step S7, and plotting the stress-strain curve, with the peak value of the curve corresponding to the composite material strength.

[0057] Compared with the prior art, the beneficial effects of the present invention are as follows: Based on the theory of microscopic failure, the present invention can describe the microscopic failure mechanism in the multi-scale analysis of composite materials. By introducing the K-means clustering algorithm, the complex microstructure can be reduced in order, thereby improving the computational efficiency and accuracy. Attached Figure Description

[0058] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0059] Figure 1 The flowchart illustrates the multi-scale analysis method for 2.5D woven composite materials that considers microscopic failure mechanisms, as described in this invention.

[0060] Figure 2 This is a first-direction view of the 2.5D woven composite material mesoscopic unit cell finite element model provided in an embodiment of the present invention;

[0061] Figure 3 This is a second-direction view of the 2.5D woven composite material mesoscopic unit cell finite element model provided in an embodiment of the present invention;

[0062] Figure 4 A schematic diagram illustrating the application of periodic boundary conditions to a single cell according to an embodiment of the present invention;

[0063] Figure 5 This is a visualization diagram of clustering of a microscopic unit cell model provided in an embodiment of the present invention;

[0064] Figure 6 A comparison chart of predicted stress-strain curves and experimental data provided for embodiments of the present invention. Detailed Implementation

[0065] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0066] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0067] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0068] This invention provides a 2.5-dimensional multi-scale analysis method for woven composite materials that considers microscopic failure mechanisms. Based on microscopic failure theory, it analyzes the damage mechanism of fiber filaments and matrix during composite material damage at the microscopic model scale.

[0069] The above method was used to perform multi-scale analysis on a 2.5D four-end twill woven T800 / EC230R composite material.

[0070] S1. Establish finite element models of 2.5D woven composite materials at the mesoscopic and microscopic unit cell levels, including mesoscopic unit cell models containing fiber bundles and the matrix surrounding the fiber bundles, such as... Figure 2 As shown, and a microscopic unit cell model including the fiber monofilament and the matrix surrounding the fiber monofilament, as shown. Figure 3 As shown.

[0071] S2. Assign component material properties and apply periodic boundary conditions to the micro-unit cell finite element model to obtain the equivalent elastic parameters of the micro-unit cell model and the strain-stress amplification factor of each element. Specific steps include:

[0072] S201. Assign material properties to the micro-unit cell finite element model, including T800 fiber monofilament and EC230R matrix. The performance parameters are shown in the table below.

[0073] Table 1 shows the mechanical properties of T800 fiber monofilaments.

[0074]

[0075] Table 2 shows the mechanical properties of the EC230R matrix.

[0076]

[0077] S202. Apply periodic boundary conditions to the microscopic unit cell finite element model, classify the nodes on the parallel boundary surfaces of the unit cell finite element model into three categories: face nodes, edge nodes, and corner nodes, and establish corresponding node sets; (Compare with...) Figure 4 The diagram shows a unit cell with periodic boundary conditions applied. The nodes are specifically divided into: (a) 3-opposite nodes: ABFE and DCGH, ABCD and EFGH, BCGF and ADHE; (b) edge nodes: AD, BC, FG and EH, DH, CG, AE and BF, DC, AB, HG and EF; (c) corner nodes: A, B, C, D, E, F, G, H. The following constraint equations are applied to the relationships between each group of nodes:

[0078]

[0079]

[0080] Where j+ and j- represent opposite faces. This represents the tensile / compressive deformation caused by a unit cell being loaded in the three principal directions. Corresponding to shear deformation in the three principal directions, The average strain of the microscopic unit cell model. This represents the distance between corresponding points on opposing boundary surfaces.

[0081] S203. The equivalent elastic parameters of the microscopic unit cell model are calculated using the volume averaging method, as follows:

[0082]

[0083]

[0084]

[0085] Where N f N represents the total number of fiber units. m σ represents the total number of matrix elements. ijk Let ε be the stress of the k-th element in the ij direction. ijk V represents the strain of the k-th element in the ij direction. k Let V be the volume of the k-th unit, and V be the total volume of the unit cell.

[0086] The equivalent elastic parameters of the T800 / EC230R micro-unit cell model are shown in the table below:

[0087] Table 3 Equivalent elastic parameters of the microscopic unit cell model

[0088]

[0089] S204. Obtain the strain-stress amplification factor of the microscopic unit cell model element. The strain-stress amplification factor characterizes the response relationship between the external strain and internal stress of each element in the microscopic model, as follows:

[0090]

[0091] Where {σ} represents the micro-stress on a single element within the unit cell model. This indicates the strain load applied externally to the unit cell model. In this invention, unit strain loads are applied in six directions: 11, 12, 13, 22, 23, and 33. [A] represents the strain-stress amplification factor.

[0092] S3. Using the K-means clustering algorithm, the strain-stress amplification factor of each unit in the microscopic unit cell model is used as feature data to perform clustering and order reduction on the microscopic model. The average strain-stress amplification factor of each unit in each cluster is used as the strain-stress amplification factor of the cluster. The visualization of the clustering effect is shown in the attached figure. Figure 5 As shown.

[0093] S4. Assign component material properties and apply periodic boundary conditions to the mesoscopic unit cell finite element model to obtain the average stress and average strain of the mesoscopic model, as well as the strain vector of the fiber bundle element and the stress vector of the matrix element. Specific steps include:

[0094] S401. Assign material properties to the micro-unit cell finite element model, including fiber bundles and matrix, where matrix performance data is referenced in Table 2 and fiber bundle performance data is referenced in Table 3.

[0095] S402. Apply periodic boundary conditions to the microscopic unit cell model, consistent with the steps described in S202.

[0096] S403. Obtain the stress vector and strain vector of each element, and calculate the average stress and average strain of the mesoscopic unit cell model using the same volume averaging method in step S204.

[0097] S404. Then obtain the strain vector of the fiber bundle element and the stress vector of the matrix element in the microscopic model.

[0098] S5. Based on the stress vector of the matrix element in step S4, combined with the damage initiation criterion von Mises failure criterion and instantaneous unloading damage propagation model, after damage, except for Poisson's ratio which remains unchanged, all other material properties degrade to 40% of their original values, thus obtaining the elastic parameters of the matrix material after damage.

[0099]

[0100]

[0101]

[0102] Where T m and C m These are the tensile strength and compressive strength of the matrix material, σ ij This represents the stress vector of the matrix.

[0103] S6. Based on the strain vector of the fiber bundle unit in step S4, and combined with the strain-stress amplification factor of the micro-cluster in step S3, calculate the stress vector of the cluster in the micro-model.

[0104] S7. Based on the stress vectors of each cluster in the microscopic model in step S6, and combined with different damage initiation criteria and damage propagation models, obtain the stiffness matrix after damage for different clusters. Combined with the microscopic equivalent elastic parameter prediction model, obtain the equivalent elastic parameters of the fiber bundle element after damage. The specific steps are as follows:

[0105] S701. Based on the stress vector of the cluster in the micro model calculated in step S6, the damage initiation criterion and damage propagation model described in step S5 above are used for the matrix cluster to obtain the elastic parameters of each matrix cluster after damage, and then the elastic parameters of the whole matrix after damage are obtained by the volume averaging method.

[0106] S702. Based on the stress vectors of the clusters in the microscopic model calculated in step S6, the maximum stress criterion is adopted for fiber clusters, and the corresponding damage variable is set to 0.999. The overall damage state of the fiber is determined by the maximum damage state among all fiber clusters.

[0107]

[0108]

[0109]

[0110] in T is used to withstand stress in the fiber direction. f and C f These are the tensile and compressive strengths of the fiber, E f The elastic modulus before fiber damage. This represents the elastic modulus after fiber damage.

[0111] S703. Based on the above steps S701 and S702, the elastic parameters of the matrix material and fiber material after damage in the microscopic model are obtained. Then, combined with the Chamis equivalent elastic parameter prediction model, the elastic performance parameters of the fiber bundle after damage are obtained, as follows:

[0112] E 11 =V f E f11 +V m E m (13)

[0113]

[0114]

[0115]

[0116] v 12 =v 13 =v m +V f (v f12 -v m (17)

[0117]

[0118] S8. Determine whether the model has ultimately failed. Specifically, when the stress borne by the material decreases with the increase of strain, the model is determined to have failed. If it has failed, proceed to the next step. If it has not failed, repeat steps S2 to S7.

[0119] Step 9: Plot the stress-strain curve. During the cycle from steps S2 to S7, read the mean stress and mean strain of the mesoscopic unit cell model calculated in step S4 of each cycle, plot the predicted stress-strain curve, and compare it with the experimental results, as shown in the appendix. Figure 6 As shown, the peak value of the curve corresponds to the strength of the 2.5D woven composite material. The results show that the stress-strain curve obtained by the multi-scale method of this invention and the experimental tensile curve are in good agreement. The tensile strength obtained by the test specimen is 1081.5 MPa, while the predicted result by the multi-scale method of this invention is 1173.0 MPa. The relative error between the multi-scale analysis result and the experimental result is 8.46%.

[0120] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms, characterized in that, include: S1. Establish finite element models of 2.5D woven composite materials at the mesoscopic and microscopic unit cell levels; S2. Assign component material properties and apply periodic boundary conditions to the micro-unit cell finite element model to obtain the equivalent elastic parameters of the micro-unit cell model and the strain-stress amplification factor of each element; S3. Using the K-means clustering algorithm, the strain-stress amplification factor of each unit in the micro-cell model is used as the feature data to cluster and reduce the order of the micro-cell model. The average strain-stress amplification factor of each unit in each cluster is used as the strain-stress amplification factor of the cluster. S4. Assign component material properties and apply periodic boundary conditions to the mesoscopic unit cell finite element model to obtain the average stress and average strain of the mesoscopic model, as well as the strain vector of the fiber bundle element and the stress vector of the matrix element. S5. Based on the stress vector of the matrix element in step S4, and combined with the damage initiation criterion and damage propagation model, obtain the elastic parameters of the matrix material after damage. S6. Based on the strain vector of the fiber bundle unit in step S4, and combined with the strain-stress amplification factor of the micro-cluster in step S3, calculate the stress vector of the cluster in the micro-model. S7. Based on the stress vectors of each cluster in the microscopic model in step S6, and combined with different damage initiation criteria and damage propagation models, obtain the stiffness matrix after damage of different clusters. Combine with the microscopic equivalent elastic parameter prediction model, obtain the equivalent elastic parameters of the fiber bundle unit after damage. S8. Determine whether the model has ultimately failed. If it has failed, plot the stress-strain curve to obtain the strength of the 2.5D woven composite material. If it has not failed, repeat steps S2 to S7.

2. The multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms according to claim 1, characterized in that, In step S2, the steps for obtaining the equivalent elastic parameters of the microscopic unit cell model and the strain-stress amplification factor of each element are as follows: S201. Assign material properties to the micro-unit cell finite element model, including fiber filaments and matrix; S202. Apply periodic boundary conditions to the microscopic unit cell finite element model as follows: Where j+ and j- represent opposite faces. This represents the tensile / compressive deformation caused by a unit cell being loaded in the three principal directions. Corresponding to shear deformation in the three principal directions, The average strain of the microscopic unit cell model. The distance between corresponding points on opposing boundary surfaces; S203. The equivalent elastic parameters of the microscopic unit cell model are calculated using the volume averaging method, as follows: Where N f N represents the total number of fiber units. m σ represents the total number of matrix elements. ijk Let ε be the stress of the k-th element in the ij direction. ijk V represents the strain of the k-th element in the ij direction. k Let V be the volume of the k-th unit, and V be the total volume of the unit cell; S204. Obtain the strain-stress amplification factor of the microscopic unit cell model element. The strain-stress amplification factor characterizes the response relationship between the external strain and internal stress of each element in the microscopic model. The method is as follows: Where {σ} represents the micro-stress on a single element within the unit cell model. This represents the strain load applied externally to the unit cell model, and [A] represents the strain-stress amplification factor.

3. The multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms according to claim 1, characterized in that, In step S3, the fiber monofilament units and matrix units in the microscopic unit cell model are clustered separately, into fiber clusters and matrix clusters.

4. The multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms according to claim 1, characterized in that, In step S4, the specific steps for obtaining the strain vector of the fiber bundle element and the stress vector of the matrix element in the mesoscopic model include: S401. Assign material properties to the micro-unit finite element model, including fiber bundles and matrix; S402. Apply periodic boundary conditions to the microscopic unit cell model; S403. Obtain the stress vector and strain vector of each element, and calculate the average stress and average strain of the mesoscopic unit cell model. S404. Obtain the strain vector of the fiber bundle element and the stress vector of the matrix element in the mesoscopic model, respectively.

5. The multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms according to claim 1, characterized in that, In step S5, the damage initiation criterion is the von Mises failure criterion, specifically: Where T m and C m These are the tensile strength and compressive strength of the matrix material, σ ij is the stress vector of the matrix.

6. The multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms according to claim 1, characterized in that, In step S7, the specific steps for obtaining the equivalent elastic parameters of the damaged fiber bundle unit include: S701. Based on the stress vector of the cluster in the micro model calculated in step S6, the damage initiation criterion and damage propagation model described in step S5 are used for the matrix cluster to obtain the elastic parameters after damage of each matrix cluster, and then the elastic parameters after damage of the whole matrix are obtained by volume averaging. S702. Based on the stress vectors of the clusters in the microscopic model calculated in step S6, the maximum stress criterion is adopted for fiber clustering, and the corresponding damage variable is set to 0.999, as follows: in To withstand stress in the fiber direction, T f and C f These are the tensile and compressive strengths of the fiber, E. f The elastic modulus before fiber damage. The elastic modulus after fiber damage is determined by the maximum damage state among all fiber clusters. S703. Based on the above steps S701 and S702, the elastic parameters of the matrix material and fiber material after damage in the microscopic model are obtained. Then, combined with the Chamis equivalent elastic parameter prediction model, the elastic performance parameters of the fiber bundle are obtained as follows: E 11 =V f E f11 +V m E m ; v 12 =v 13 =v m +V f (v f12 -v m ); 7. The multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms according to claim 1, characterized in that, The final failure criterion for the model in step S8 is specifically determined when the stress borne by the material decreases with the increase of strain, indicating that the model has failed.

8. The multi-scale analysis method for 2.5D woven composite materials considering microscopic failure mechanisms according to claim 1, characterized in that, In step S8, plotting the stress-strain curve requires reading the average stress and average strain of the mesoscopic unit cell model calculated in step S4 of each cycle step from step S2 to step S7, and plotting the stress-strain curve. The peak value of the curve corresponds to the strength of the composite material.

Images