Uniaxial tensile failure simulation analysis method for ceramic matrix composite tenon feature structure
By simulating uniaxial tensile failure of CMC tenon structures through cross-scale analysis and VUMAT subroutines, the problem of simulating damage initiation and failure mode transition in existing technologies has been solved, achieving accuracy and cost-effectiveness in structural design.
Patent Information
- Application Number
- CN202511596982.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-04
- Publication Date
- 2026-01-27
AI Technical Summary
Existing technologies are difficult to accurately simulate the damage initiation and evolution process of ceramic matrix composite (CMC) tenon structures during uniaxial tension, as well as their failure mode transition mechanism, and the testing costs are high.
A cross-scale analysis method was used to establish a microscopic model of CMC fiber-matrix. By writing a VUMAT subroutine, the material characteristic constitutive model was introduced into the macroscopic model to simulate the internal interface performance of the tenon and analyze the uniaxial tensile failure process and failure mechanism of the tenon structure.
It accurately simulates the damage initiation and evolution process of CMC tenon structure, guides structural design, and reduces testing costs.
Smart Images
Figure CN121413136A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a simulation analysis method for uniaxial tensile failure of tenon feature structures in ceramic matrix composites, belonging to the field of tensile mechanical properties and failure mechanism analysis of ceramic matrix composite structures. Background Technology
[0002] Ceramic matrix composites (CMCs) have advantages such as good high-temperature performance, low density, high specific strength and strong creep resistance. Their preparation process, performance design and application in components such as combustion chambers and turbines have become hot topics in the field of aero-engine research.
[0003] Among them, the CMC turbine blade tenon, as the medium connecting the blade and the disk, bears most of the centrifugal load and aerodynamic bending moment. Due to factors such as its layup scheme, molding method and manufacturing process, the failure mechanism of this structure is complex. By simulating the centrifugal load on the structure in the form of uniaxial tension, multiple failure modes are finally obtained, such as brittle fracture at the neck or delamination failure at the bottom, and the test cost is extremely high.
[0004] Finite element simulation analysis technology is becoming increasingly mature and can accurately simulate the mechanical properties of structures. Some scholars have already established finite element models to analyze the uniaxial tensile mechanical properties and failure modes of CMC tenon structures. However, few studies have conducted detailed analyses of the initiation and evolution of internal damage during the tensile process of tenon structures, as well as the failure mode transition mechanism, based on the constitutive characteristics of the materials. The ABAQUS finite element analysis software supports user-defined subroutines to achieve this function. Based on this, a finite element simulation analysis method for the tensile failure process of tenon structures can be established, which can help study the failure mechanism of CMC tenon structures and guide structural design. Summary of the Invention
[0005] To address the aforementioned problems, this invention proposes a simulation analysis method for uniaxial tensile failure of ceramic matrix composite tenon features. A cross-scale analysis approach is used to establish a microscopic model of the CMC fiber-matrix structure to extract material constitutive features. This model is then incorporated into the macroscopic CMC tenon model using a VUMAT subroutine as a criterion for dynamically calculating the damage initiation and evolution of the structure. Furthermore, an adhesive layer is added between the internal interfaces of the tenon to simulate interface properties, thereby enabling the analysis of the uniaxial tensile failure process and mechanism of the tenon features.
[0006] The simulation analysis method for uniaxial tensile failure of the ceramic matrix composite tenon feature structure described in this invention comprises the following steps:
[0007] Step 1: Establish a longitudinal tensile microstructure model of the corresponding CMC system in ABAQUS finite element analysis software, with the fiber being green and the matrix white.
[0008] In the microscopic model, the fiber and the matrix are each divided into several units. Two sets of material property values are assigned to the fiber and the matrix respectively: one set is the initial material property, and the other set is the material property after damage. Different field variable values correspond to them.
[0009] The simulation parameters include those of the SiC fibers and the SiC matrix. Both parameters include the elastic modulus along the fiber direction. Elastic modulus perpendicular to fiber direction Poisson's ratio The Weibull distribution scale parameter and the Weibull distribution shape parameter;
[0010] Step 2: Introduce the random failure strength of the fiber and matrix into the microstructure model through the VUSDFLD subroutine, and then perform uniaxial tensile simulation. Obtain the uniaxial tensile stress-strain curve of the model from the simulation results, and fit the bilinear characteristic material constitutive model of CMC along the fiber direction.
[0011] The VUSDFLD subroutine defines the random failure intensity of each fiber / matrix unit, and makes all failure intensities satisfy the Weibull distribution. As the displacement load increases, the tensile stress on the unit increases continuously. When the stress on some fiber / matrix units reaches the assigned failure intensity value, the unit is considered to have failed.
[0012] The reduction of material properties of a unit is achieved by changing the value of the field variable of each unit. Specifically, the initial field variable of each fiber / matrix unit is 0. As the stress increases, when the unit reaches the failure strength, the field variable changes from 0 to 1, and the corresponding material property value is the reduced material.
[0013] Step 3: In the ABAQUS finite element analysis software, establish a uniaxial tensile macroscopic model of the CMC tenon feature structure. The outside of the tenon is the shape region, and the inside contains structural layers and insertion layers. Divide different regions according to the actual layup information, define the material direction, and add an adhesive layer to simulate the internal interface of the tenon.
[0014] The macroscopic model includes tenons, side reinforcement plates, and mortise and tenon components, and assigns corresponding material properties to each component.
[0015] Key simulation parameters for the tenon in the macroscopic model include damage initiation strength; damage initiation strain; final failure strength; final failure strain; and elastic modulus along the fiber direction. Elastic modulus perpendicular to fiber direction shear modulus and Poisson's ratio and ;
[0016] The outer tenon's shaped area is an orthogonal ply, the inner unidirectional area is a 0° mid-plane projection ply, and the adhesive layer is added at the interface between the inner and outer areas of the tenon and the interface between the internal structural layer and the insertion layer group.
[0017] Step 4: Create a dynamic display analysis step for the macroscopic model and define the geometric constraints, boundary conditions, and displacement loads of the model.
[0018] Step 5: Based on the bilinear characteristic material constitutive model and the user-defined damage state variables, write the VUMAT subroutine to dynamically update the reduced stiffness matrix of the macroscopic model; and weaken the strength of the continuous triangular region on the inclined surface of the tenon insertion layer where porosity defects are easily formed.
[0019] The update process for the reduced stiffness matrix of the macroscopic model is as follows:
[0020] Step 501: Input the initial material properties in the VUMAT subroutine and calculate the initial stiffness matrix of the element;
[0021] Step 502: Based on the uniaxial tensile stress-strain curve of the microscopic model, determine the damage initiation strength and final failure strength values, and define the damage state variables.
[0022] Step 503: As the element strain increases, calculate the element stress based on the stiffness matrix;
[0023] Step 504: Determine whether the stress value has reached the damage initiation strength. If so, the element is considered to have entered damage, and the damage state variables are calculated. Proceed to step 505. Otherwise, return to step 503 and continue to increase the element strain until the stress value reaches the damage initiation strength.
[0024] Step 505: Recalculate the reduced stiffness matrix based on the damage state variables, and return to step 503. Calculate the element stress using the updated reduced stiffness matrix. Continue until the stress value reaches the final failure strength, at which point the element is considered completely damaged and deleted.
[0025] Furthermore, for the tenon insertion layer, single-layer boards of varying lengths are used. When stacked together, their tips form a stepped slope. The resulting continuous triangular area is prone to porosity defects during the tenon component manufacturing process. For the unit in this continuous triangular area, both the initial damage strength and the final failure strength are lower than normal values.
[0026] Step 6: Conduct uniaxial tensile simulation analysis of the CMC tenon feature structure using the VUMAT subroutine. By changing the tenon interface performance parameters, different failure modes are obtained, and the failure mechanism is analyzed.
[0027] The advantages of this invention are:
[0028] (1) The present invention uses a multi-scale analysis method to transfer the constitutive model of the microscopic model to the macroscopic model, and accurately simulates the initiation and evolution of structural damage.
[0029] (2) The present invention uses adhesive layer units to simulate the internal interface performance of the tenon and analyzes the influence of the interlayer performance of the tenon on the failure mode. Attached Figure Description
[0030] Figure 1 This is a flowchart of the simulation analysis method for uniaxial tensile failure of the ceramic matrix composite tenon feature structure of the present invention;
[0031] Figure 2 This is a schematic diagram of the porosity defects in the triangular region formed by the tenon insertion layer assembly of the present invention;
[0032] Figure 3 This is a schematic diagram of the microstructure of the CMC fiber-matrix of the present invention;
[0033] Figure 4 This is a fitting diagram of the constitutive curve of the CMC microscopic model of the present invention;
[0034] Figure 5 This is a schematic diagram of the boundary conditions of the macroscopic model of the uniaxial tension of the CMC tenon feature structure of the present invention;
[0035] Figure 6 This is a flowchart of the VUMAT subroutine execution of the present invention;
[0036] Figure 7 This is a comparison diagram of different failure modes of the CMC tenon feature structure of the present invention;
[0037] Figure 8 This is a comparison diagram of the load-displacement curves of the CMC tenon feature structure of the present invention. Detailed Implementation
[0038] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0039] This invention proposes a simulation analysis method for uniaxial tensile failure of a tenon feature structure in ceramic matrix composites, such as... Figure 1 As shown, the specific steps are as follows:
[0040] Step 1: Establish a longitudinal tensile microstructure model of the corresponding CMC system in ABAQUS finite element analysis software, with the fiber being green and the matrix white.
[0041] In the aforementioned microscopic model, both the fiber and the matrix are divided into several units. Two sets of material property values are assigned to each fiber / matrix: one set represents the initial material properties, and the other represents the properties after damage, each corresponding to a different field variable value. Material properties include modulus, Poisson's ratio, etc.
[0042] The simulation parameters include those of the SiC fibers and the SiC matrix. Both parameters include the elastic modulus along the fiber direction. Elastic modulus perpendicular to fiber direction Poisson's ratio The Weibull distribution scale parameter and the Weibull distribution shape parameter;
[0043] Step 2: Introduce the random failure strength of the fiber and matrix into the microstructure model through the VUSDFLD subroutine, and then perform uniaxial tensile simulation. Obtain the uniaxial tensile stress-strain curve of the model from the simulation results, and fit the bilinear characteristic material constitutive model of CMC along the fiber direction.
[0044] The VUSDFLD subroutine defines the random failure intensity of each fiber / matrix unit, and makes all failure intensities satisfy the Weibull distribution. As the displacement load increases, the tensile stress on the unit increases continuously. When the stress on some fiber / matrix units reaches the assigned failure intensity value, the unit is considered to have failed.
[0045] The VUSDFLD subroutine supports user-defined field variables to control the material properties of elements in the model. By changing the value of the field variable of each element, the material properties of that element can be reduced. Specifically, the initial field variable of each fiber / matrix element is 0. As the stress increases, when the element reaches the failure strength, the field variable changes from 0 to 1, and the corresponding material property value is the reduced material. That is, the material property corresponding to field variable 1 is obtained by reducing the material property corresponding to field variable 0.
[0046] Step 3: In the ABAQUS finite element analysis software, establish a uniaxial tensile macroscopic model of the CMC tenon feature structure. The outside of the tenon is a three-dimensional region, and the inside contains structural layers and insert layers to achieve thickness variation. Divide different regions according to the actual layup information, define the material direction, and add an adhesive layer to simulate the internal interface of the tenon.
[0047] The macroscopic model includes tenons, side reinforcement plates, and mortise and tenon components, and assigns corresponding material properties to each component.
[0048] Key simulation parameters for the tenon in the macroscopic model include damage initiation strength; damage initiation strain; final failure strength; final failure strain; and elastic modulus along the fiber direction. Elastic modulus perpendicular to fiber direction shear modulus and Poisson's ratio and ;
[0049] The outer tenon's shaped area is an orthogonal ply, the inner unidirectional area is a 0° mid-plane projection ply, and the adhesive layer is added at the interface between the inner and outer areas of the tenon and the interface between the internal structural layer and the insertion layer group.
[0050] Step 4: Create a dynamic display analysis step for the macroscopic model and define the geometric constraints, boundary conditions, and displacement loads of the model.
[0051] Step 5: Based on the bilinear characteristic material constitutive model and the user-defined damage state variables, write the VUMAT subroutine to dynamically update the reduced stiffness matrix of the macroscopic model; and weaken the strength of the continuous triangular region in the tenon variable thickness region where the inclined surface of the inserted layer group is prone to forming pore defects.
[0052] The VUMAT subroutine supports user-defined material properties and various functions such as real-time updates of the material stiffness matrix.
[0053] The update process for the reduced stiffness matrix of the macroscopic model is as follows:
[0054] Step 501: Input the initial material properties in the VUMAT subroutine and calculate the initial stiffness matrix of the element;
[0055] Step 502: Based on the uniaxial tensile stress-strain curve of the microscopic model, determine the damage initiation strength and final failure strength values, and define the damage state variables.
[0056] Step 503: As the element strain increases, calculate the element stress based on the stiffness matrix;
[0057] Step 504: Determine whether the stress value has reached the damage initiation strength. If so, the element is considered to have entered damage, and the damage state variables are calculated. Proceed to step 505. Otherwise, return to step 503 and continue to increase the element strain until the stress value reaches the damage initiation strength.
[0058] Step 505: Recalculate the reduced stiffness matrix based on the damage state variables, and return to step 503. Calculate the element stress using the updated reduced stiffness matrix. Continue until the stress value reaches the final failure strength, at which point the element is considered completely damaged and deleted.
[0059] Furthermore, for the layered units inserted in the thicker areas of the tenon, single-layer boards of varying lengths are used. When stacked together, their tips form a stepped bevel, such as... Figure 2 As shown, a continuous triangular gap (red) is formed on one side of the slope between the top-to-bottom structural layer (light color) and the inserted layer group (dark color). The continuous triangular area formed is prone to porosity defects during the tenon component manufacturing process. For the unit in this continuous triangular area, the damage initiation strength and final failure strength are both lower than normal values.
[0060] Step 6: Conduct uniaxial tensile simulation analysis of the CMC tenon feature structure using the VUMAT subroutine. By changing the tenon interface performance parameters, different failure modes are obtained, and the failure mechanism is analyzed.
[0061] Example:
[0062] Step 1: In ABAQUS, establish a longitudinal tensile microscopic model of the CMC fiber-matrix corresponding material system, create a dynamic display analysis step, and apply boundary conditions to the model with one end fixed and the other end displaced.
[0063] Step 2: Based on the VUSDFLD subroutine of ABAQUS, introduce random failure intensities of the fiber and matrix, making the failure intensities of the fiber and matrix follow a Weibull distribution:
[0064]
[0065] in, For fiber monofilament mesh size, For fiber characteristic length, This represents the actual tensile strength of the fiber monofilament. and The scale and shape parameters are the Weibull distribution of the tensile strength of a fiber monofilament.
[0066]
[0067] in, For the actual strength of the matrix, and The scale and shape parameters of the matrix strength Weibull distribution are given.
[0068] The maximum stress criterion is used to determine whether an element has entered damage. The stiffness of damaged elements is reduced, and the uniaxial tensile stress-strain curve of the model is output. The curve is then fitted to an idealized CMC bilinear characteristic material constitutive model.
[0069] Step 3: Create a uniaxial tensile model of the CMC tenon feature structure in ABAQUS, including the tenon, side reinforcement plates, and mortise components, and assign corresponding material properties to each component. Based on the tenon ply information, first divide it into an outer dimensional region and an inner unidirectional region. Within the inner unidirectional region, define the number of structural layers, the number of inserted layers, and the distribution location of the inserted layers, and define the material orientation based on the ply information. Add an adhesive layer between the longer inserted layer and the structural layer to simulate interface properties, and mesh the solid and adhesive layers using C3D8R elements and COHESIVE elements respectively.
[0070] Step 4: Create a dynamic display analysis step, define the surface-to-surface contact between the tenon and the mortise, bind the reinforcing plate to the tenon clamping surface, set a fixed support constraint on the bottom of the mortise, and couple the side of the reinforcing plate to the loading point to apply a displacement load.
[0071] Step 5: Using the VUMAT subroutine based on ABAQUS, incorporate the bilinear characteristic constitutive model, failure strength, and damage state variables of the CMC material obtained in Step 2. Write the VUMAT subroutine in FORTRAN, assigning engineering constants to the CMC, and considering only tensile damage along the fiber direction and perpendicular to the fiber direction. The constitutive model perpendicular to the fiber direction is defined as a conventional material constitutive model, providing the failure strain / strength; the bilinear characteristic constitutive model is defined along the fiber direction, providing the damage initiation strain / strength and failure strain / strength. Calculate the damage state variables according to different damage stages using the maximum strain criterion.
[0072]
[0073] in The degree of damage along the fiber direction, and Damage initiation strain / strength along the fiber direction, and The failure strain / strength is along the fiber direction.
[0074]
[0075] in The degree of damage is perpendicular to the fiber direction. The failure strain is perpendicular to the fiber direction.
[0076] The reduced stiffness matrix is dynamically updated based on the damage state variables:
[0077]
[0078] Where C is the initial stiffness matrix and CD is the reduced stiffness matrix. For the continuous triangular region on the inclined surface of the inserted layer group that is prone to porosity, its strength is weakened.
[0079] Step 6: Conduct uniaxial tensile simulation analysis of the CMC tenon feature structure, obtain different failure modes by changing the tenon interface performance parameters, and analyze the failure mechanism.
[0080] By changing the parameters and repeating the calculations of the macroscopic model, the impact of interlayer performance on failure modes can be analyzed by comparing the results.
[0081] The following example illustrates the uniaxial tensile failure process of a tenon feature structure in a SiC / SiC material system prepared by a non-reactive melting infiltration process.
[0082] The two-dimensional CMC fiber-matrix uniaxial tensile microscopic model established in this embodiment has a size of 750×250um, contains 30 fibers, and has a fiber volume fraction of 40%. The relevant simulation parameters are shown in Table 1 below. The material parameters after damage are 50% of the initial parameters. The established CMC tenon feature structure uniaxial tensile macroscopic model has the following dimensions: tenon height 9.8mm, tenon neck width 11.3mm, tenon diameter width 18.5mm, tenon apex angle 60°, tenon base angle 45°, bottom surface height 4.4mm, and overall height 61mm. The relevant simulation parameters are shown in Table 2 below.
[0083] Table 1. Simulation parameters of the microscopic model
[0084]
[0085] Table 2 Simulation parameters of macroscopic model
[0086]
[0087] The tensile failure process of CMC tenon features was analyzed using a multi-scale method. The specific steps are as follows:
[0088] (1) Establish the above fiber-matrix uniaxial tensile microstructure model, fix one end of it, apply displacement load to the other end, create a dynamic analysis step, divide the mesh, and take the mesh size of 75um along the fiber direction.
[0089] (2) Uniaxial tensile simulation was performed using the VUSDFLD subroutine of ABAQUS, and the stress-strain curve was extracted and fitted to an idealized bilinear characteristic constitutive curve. The established mesoscopic model is as follows: Figure 3 As shown, the extracted stress-strain curves and the fitted curves are as follows: Figure 4 As shown.
[0090] (3) Import the tenon, mortise, and reinforcing plate components to establish a uniaxial tensile macroscopic model, and reduce it to a quarter model according to the principle of symmetry. Assign material properties: the reinforcing plate is made of aluminum, the mortise is made of No. 45 structural steel, and the tenon is made of SiC / SiC unidirectional strip. Divide different regions according to the actual ply information of the tenon, define the material direction, the outer dimensional region is orthogonal ply, and the inner unidirectional region is 0° ply of the mid-plane projection. Add adhesive layers to the inner and outer interfaces and between the longer insert layer and the structural layer to simulate the interface performance. Divide the structured mesh and define the area below the clamping section as the damage occurrence area.
[0091] (4) Define the geometric constraints, displacement loads, and boundary conditions for the model according to step 4. Since a quarter-model is used, two additional symmetry plane constraints need to be applied, such as... Figure 5 As shown.
[0092] (5) Based on the VUMAT subroutine of ABAQUS, define the bilinear material constitutive and damage state variables of CMC along the fiber direction. According to step 2, the initial damage strength along the fiber direction is 130MPa and the final failure strength is 375MPa.
[0093] The subroutine execution logic is as follows: Figure 6 As shown, only tensile damage along the fiber direction and perpendicular to the fiber direction is considered, and the material damage degree and stiffness reduction matrix are recalculated each time. For the continuous small triangular region on the inclined surface of the inserted layer group, strength weakening treatment is performed at the corresponding position, reducing its strength to 70% of the original.
[0094] (6) Uniaxial tensile simulation analysis of the CMC tenon's characteristic structure was conducted. The structural failure mode was neck fracture. After reducing the strength of the adhesive layer at the inner and outer interfaces of the tenon, another uniaxial tensile simulation was performed, and the structural failure mode changed to bottom delamination failure. Comparison of the two failure modes with the actual experimental results is as follows: Figure 7 As shown, the corresponding load-displacement curve is as follows: Figure 8 As shown, the failure load corresponding to the failure mode of neck fracture is 51.63 kN, and the failure load corresponding to the failure mode of bottom delamination is 46.97 kN.
Claims
1. A simulation analysis method for uniaxial tensile failure of tenon features in ceramic matrix composite materials, characterized in that, Step 1: Establish a longitudinal tensile mesoscopic model of the corresponding CMC system (green fiber, white matrix) in ABAQUS finite element analysis software; In the microscopic model, the fiber and the matrix are each divided into several units, and two sets of material property values are assigned to the fiber / matrix respectively; one set is the initial material property, and the other set is the material property after damage, corresponding to different field variable values. Step 2: Introduce the random failure strength of the fiber and matrix into the microstructure model through the VUSDFLD subroutine, and then perform uniaxial tensile simulation. Obtain the uniaxial tensile stress-strain curve of the model from the simulation results, and fit the bilinear characteristic material constitutive model of CMC along the fiber direction. The VUSDFLD subroutine defines the random failure intensity of each fiber / matrix unit, and makes all failure intensities satisfy the Weibull distribution. As the displacement load increases, the tensile stress on the unit increases continuously. When the stress on some fiber / matrix units reaches the assigned failure intensity value, the unit is considered to have failed. Step 3: In the ABAQUS finite element analysis software, establish a uniaxial tensile macroscopic model of the CMC tenon feature structure. The outside of the tenon is the shape region, and the inside contains structural layers and insertion layers. Divide different regions according to the actual layup information, define the material direction, and add an adhesive layer to simulate the internal interface of the tenon. Step 4: Create a dynamic explicit analysis step for the macroscopic model and define the geometric constraints, boundary conditions, and displacement loads of the model; Step 5: Based on the bilinear characteristic material constitutive model and the user-defined damage state variables, write the VUMAT subroutine to dynamically update the reduced stiffness matrix of the macroscopic model; and weaken the strength of the continuous triangular region on the inclined surface of the tenon insertion layer where porosity defects are easily formed. The update process for the reduced stiffness matrix of the macroscopic model is as follows: Step 501: Input the initial material properties in the VUMAT subroutine and calculate the initial stiffness matrix of the element; Step 502: Based on the uniaxial tensile stress-strain curve of the mesoscopic model, determine the damage initiation strength and final failure strength values, and define the damage state variables; Step 503: As the element strain increases, calculate the element stress based on the stiffness matrix; Step 504: Determine whether the stress value has reached the damage initiation strength. If so, the element is considered to have entered damage, and the damage state variables are calculated. Proceed to step 505. Otherwise, return to step 503 and continue to increase the element strain until the stress value reaches the damage initiation strength. Step 505: Recalculate the reduced stiffness matrix based on the damage state variables, and return to step 503. Calculate the element stress using the updated reduced stiffness matrix. Continue until the stress value reaches the final failure strength, at which point the element is considered completely damaged and deleted. Step Six: Conduct uniaxial tensile simulation analysis of the CMC tenon feature structure using the VUMAT subroutine. By changing the tenon interface performance parameters, different failure modes are obtained, and the failure mechanism is analyzed.
2. The method as described in claim 1, characterized in that, In step one, the microscopic model simulation parameters include parameters of SiC fibers and SiC matrix, both of which include: elastic modulus along the fiber direction. Elastic modulus perpendicular to fiber direction Poisson's ratio The Weibull distribution scale parameter and the Weibull distribution shape parameter.
3. The method as described in claim 1, characterized in that, In step two, the material properties of the unit are reduced by changing the value of the field variable of each unit. Specifically, the initial field variable of each fiber / matrix unit is 0. As the stress increases, when the unit reaches the failure strength, the field variable changes from 0 to 1, and the corresponding material property value is the reduced material.
4. The method as described in claim 1, characterized in that, In step three, the macro model includes tenons, side reinforcing plates, and mortise and tenon components, and assigns corresponding material properties to each component. The key simulation parameters for the tenon in the macroscopic model include damage initiation strength and damage initiation strain. Final failure strength; Final failure strain; elastic modulus along the fiber direction Elastic modulus perpendicular to fiber direction shear modulus and Poisson's ratio and ; The outer tenon area is an orthogonal ply, the inner unidirectional area is a 0° ply with mid-plane projection, and the adhesive layer is added at the interface between the inner and outer areas of the tenon and the interface between the internal structural layer and the insertion layer group.
5. The method as described in claim 1, characterized in that, In step five, for the tenon insertion layer group, single-layer boards of varying lengths are used. When stacked together, their tips will form a stepped slope. The continuous triangular area formed is prone to porosity defects during the tenon component preparation process. For the unit of this continuous triangular area, the damage initiation strength and final failure strength are both lower than normal values.
6. The method as described in claim 1, characterized in that, In step five, the maximum strain criterion is used to calculate the damage state variables according to different damage stages: ； in The degree of damage along the fiber direction, and Damage initiation strain / strength along the fiber direction, and Failure strain / strength along the fiber direction Strain along the fiber direction.