COMSOL-based curing multi-field coupling simulation modeling method for composite materials with different layering parameters

Abstract

The invention discloses a COMSOL-based curing multi-field coupling simulation modeling method for composite materials with different layer parameters, and relates to the technical field of composite material curing molding simulation prediction. Comprising the steps that a finite element model is initialized according to the geometric dimension of the composite material structural part, a local coordinate system of the composite material structural part is obtained through the finite element model, the layering direction is calibrated, and local coordinate systems of different layering directions are established according to a rotating coordinate system; determining a physical field based on a heat-chemical-force-fluid-solid multi-field coupling model, and taking definition parameters of the composite material structural member in the calculation process as input of a variable module; and on the basis of a heat-chemical-force-fluid-solid multi-field coupling model, setting load boundary conditions, and calculating curing forming defects of the composite material structural member with different laying layer parameters. According to the method, molding defect prediction of composite material structural parts with different layer parameters can be realized, and a new modeling thought is provided for accurate prediction of molding defects of composite materials with complex structures.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material curing molding simulation prediction, and in particular to a COMSOL-based multi-field coupling simulation modeling method for composite material curing with different layer parameters. Background Art

[0002] Fiber-reinforced composite materials can significantly reduce the mass of structural parts due to their advantages such as high specific strength and specific stiffness. In addition, the fibers can be designed to be arranged according to the load path to meet the stiffness requirements of the structural parts. However, fiber-reinforced composite materials are demolded after the curing process, which usually produces a certain difference from the original design shape. Although the prepreg is laid according to the mold shape during the laying stage, the anisotropy of the thermodynamic properties of the composite material, its thermal expansion coefficient, curing shrinkage rate, interlayer stiffness and laying direction, and the flow compaction process of the resin under external loads will have an important impact on the curing molding results, resulting in wrinkles, thickness tolerances, uneven resin content, and non-uniform curing residual stress, thereby reducing manufacturing accuracy.

[0003] With the increasing demand for stability and production accuracy of composite structural parts in the aerospace and automotive industries, the traditional trial and error method is costly, inefficient and poorly controllable when applied to the automated manufacturing process. It is difficult to achieve higher manufacturing efficiency and ensure reproducible quality of molded parts. Therefore, it is necessary to characterize and model the process with the help of finite element analysis to achieve the prediction and optimization of molding defects before the molding of composite structural parts. Since the fiber direction, i.e., the ply parameters of composite structural parts, are closely related to the rigidity and molding defects of molded parts, COMSOL, as an efficient multi-physics field simulation tool, has two difficulties in establishing a composite material curing simulation model with multi-directional plies: characterization of multi-directional plies and establishment of a three-dimensional curing multi-field coupling model. How to accurately characterize the curing molding process of composite materials considering ply parameters and effectively predict curing molding defects is a key factor in understanding the mechanism of curing molding defects and effectively controlling molding defects.

[0004] Therefore, it is an urgent problem for technical personnel in this field to propose a multi-field coupling simulation modeling method for composite material curing with different layup parameters based on COMSOL to solve the difficulties existing in the prior art. Summary of the invention

[0005] In view of this, the present invention provides a multi-field coupling simulation modeling method for composite material curing with different layup parameters based on COMSOL, which can realize the prediction of molding defects of composite material structural parts with different layup parameters and provide a new modeling idea for the accurate prediction of molding defects of complex structure composite materials.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL, comprising the following steps:

[0008] S1. Initialize a finite element model according to the geometric dimensions of the composite structure, obtain a local coordinate system of the composite structure using the finite element model, calibrate the ply direction, and establish a local coordinate system of different ply directions according to the rotating coordinate system;

[0009] S2. Based on the thermal-chemical-mechanical-fluid-solid multi-field coupling model, determine the physical field and use the definition parameters of the composite structure in the calculation process as the input of the variable module;

[0010] S3. Based on the thermal-chemical-mechanical-fluid-solid multi-field coupling model, the load boundary conditions are set, and each ply is placed in the local coordinate system of different ply directions established in S1 according to the ply direction, and the curing defects of composite structural parts with different ply parameters are calculated.

[0011] In the above method, optionally, in S1, a curvilinear coordinate system module is used to obtain a local coordinate system of the composite material structure, calibrate a 0° ply direction for laying according to a geometric shape, and calculate a local coordinate system of a single-layer composite material with different ply angles by using a rotating coordinate system transformation.

[0012] The above method optionally establishes a curvilinear coordinate system module based on the Navier-Stokes equation, constructs a local coordinate system of the composite structure based on the streamline equation, and uses the rotation coordinate system to convert and calculate the local coordinate system of the single-layer composite material with different ply angles. When the ply angle is θ, the local coordinate system of the single-layer composite material is first defined by rotating the θ angle rotation coordinate system. The expression of the coordinate transformation of the rotation coordinate system is as follows:

[0013]

[0014] Among them, v i (i=x,y,z) represents the coordinates after rotation, v i (i=X,Y,Z) represents the coordinates before rotation;

[0015] Based on the curvilinear coordinate system solved by the rotating coordinate system and the streamline equation, the composite coordinate system is used to define the local coordinate system in the ply direction other than 0°. The composite coordinate system acts as a continuous application of two independent coordinate systems. The curvilinear coordinate system is set as the basic system coordinate system, that is, the basis vector is defined, and the rotating coordinate system is set as the relative coordinate system, that is, the rotation matrix of the angle ply is defined. The expression of the coordinate transformation of the composite coordinate system is as follows:

[0016]

[0017] Among them, e θi (i=1,2,3) represents the basis vectors of the local coordinate system after rotation.

[0018] In the above method, optionally, the thermal-chemical-mechanical-fluid-solid multi-field coupling model in S2 includes a thermal-chemical coupling temperature field calculation model, a thermal-mechanical coupling stress field calculation model and a fluid-solid coupling model;

[0019] The thermal-chemical coupled temperature field calculation model includes a heat conduction model and a curing kinetics model;

[0020] A thermal-mechanical coupling stress field calculation model is established based on the stress-strain relationship, thermal expansion of the resin and the curing shrinkage effect;

[0021] The fluid-structure interaction model is represented based on mass conservation, resin flow continuity, and Darcy's law.

[0022] In the above method, optionally, the expression of the thermal-chemical coupling temperature field calculation model is:

[0023]

[0024] Wherein, m and n represent the curing reaction order, and K0 represents the reaction rate constant;

[0025] The expression of the thermal-mechanical coupling stress field calculation model is:

[0026] σ=Cε

[0027] ε=ε e +ε th +ε sh

[0028] Where, σ represents the curing stress, C represents the composite stiffness matrix, ε represents the curing strain, and ε e represents the elastic strain, ε th represents the thermal expansion strain, ε th represents the curing shrinkage strain;

[0029] The expression of the fluid-structure coupling model is:

[0030]

[0031] P a =P+σ f

[0032] Among them, S ii(i＝x,y,z) represents the fiber bed permeability, μ represents the resin viscosity, P represents the resin pressure, ε v represents volumetric strain, σ f represents the effective stress of the fiber, P aIndicates that external load is applied.

[0033] In the above method, optionally, the parameters defined in S2 include thermodynamic performance parameters, time-varying characteristic expressions and curing process curves;

[0034] Thermodynamic performance parameters include thermal performance parameters and mechanical performance parameters. Thermal performance parameters include thermal conductivity and specific heat capacity. Mechanical performance parameters include modulus, Poisson's ratio, density, fiber volume fraction, and thermal expansion coefficient.

[0035] The material property expression based on the law of mixtures is:

[0036] ρ c =V f ρ f +V m ρ m

[0037] C c =V f C f +V m C m

[0038] Among them, f represents fiber, m represents resin, V represents volume fraction, ρ represents density, and C represents specific heat capacity;

[0039] The expression based on the time-varying properties of the material is:

[0040]

[0041] Where E m 、v m and G m They represent the elastic modulus, Poisson's ratio and shear modulus of the resin respectively. and Respectively represent the elastic modulus of the resin at the beginning and end of curing, α gel Indicates the degree of solidification at the gel point, α mod It is a function of the degree of cure and the gel point.

[0042] In the above method, optionally, the variable modules in S2 include a curvilinear coordinate module, a solid heat transfer module, a coefficient form partial differential equation module, a Darcy's law module, and a solid mechanics module.

[0043] The above method can optionally construct a thermal-chemical-mechanical-fluid-solid multi-field coupling model based on the COMSOL platform.

[0044] It can be seen from the above technical scheme that compared with the prior art, the present invention provides a multi-field coupling simulation modeling method for composite material curing with different layup parameters based on COMSOL, which has the following beneficial effects: the present invention not only realizes the establishment of a thermal-chemical-mechanical-fluid-solid multi-field coupling model of the curing process, but also provides a composite material modeling method with different layup parameters based on COMSOL software, which can realize the prediction of molding defects of composite material structural parts with different layup parameters, and provides a new modeling idea for the accurate prediction of complex structure composite molding defects, which has important guiding significance for reducing curing molding defects by optimizing layup parameters, thereby preparing high-performance composite structural parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0046] Figure 1 A flow chart of a multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL provided by the present invention;

[0047] Figure 2 A flow chart of the thermal-chemical-mechanical-fluid-solid multi-field coupling model provided by the present invention;

[0048] Figure 3 A schematic diagram of finite element mesh division of an L-shaped part provided by the present invention;

[0049] Figure 4 A schematic diagram of the load boundary conditions of an L-shaped member provided by the present invention;

[0050] Figure 5 A schematic diagram of the local coordinate system setting of prepregs in different ply directions provided by the present invention;

[0051] Figure 6 A numbering diagram of L-shaped parts with different ply parameters provided by the present invention;

[0052] Figure 7 A schematic diagram of thickness variation corresponding to L-shaped part numbers with different ply parameters provided by the present invention;

[0053] Figure 8 Schematic diagram of the non-uniform resin content distribution in the corner area of ​​the L-shaped part with different layup parameters provided by the present invention. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Reference Figure 1 As shown, the present invention discloses a multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL, comprising the following steps:

[0056] S1. Initialize a finite element model according to the geometric dimensions of the composite structure, obtain a local coordinate system of the composite structure using the finite element model, calibrate the ply direction, and establish a local coordinate system of different ply directions according to the rotating coordinate system;

[0057] S2. Based on the thermal-chemical-mechanical-fluid-solid multi-field coupling model, determine the physical field and use the definition parameters of the composite structure in the calculation process as the input of the variable module;

[0058] S3. Based on the thermal-chemical-mechanical-fluid-solid multi-field coupling model, the load boundary conditions are set, and each ply is placed in the local coordinate system of different ply directions established in S1 according to the ply direction, and the curing defects of composite structural parts with different ply parameters are calculated.

[0059] Furthermore, a curvilinear coordinate system module is established based on the Navier-Stokes equation, and a local coordinate system of a composite structure is constructed based on the streamline equation. The local coordinate system of a single-layer composite material with different ply angles is calculated using the rotation coordinate system transformation. When the ply angle is θ, the local coordinate system of a single-layer composite material is first defined by rotating the θ angle rotation coordinate system. The expression for the coordinate transformation of the rotation coordinate system is as follows:

[0060]

[0061] Among them, v i (i=x,y,z) represents the coordinates after rotation, v i (i=X,Y,Z) represents the coordinates before rotation;

[0062] Based on the curvilinear coordinate system solved by the rotating coordinate system and the streamline equation, the composite coordinate system is used to define the local coordinate system in the ply direction other than 0°. The composite coordinate system acts as a continuous application of two independent coordinate systems. The curvilinear coordinate system is set as the basic system coordinate system, that is, the basis vector is defined, and the rotating coordinate system is set as the relative coordinate system, that is, the rotation matrix of the angle ply is defined. The expression of the coordinate transformation of the composite coordinate system is as follows:

[0063]

[0064] Among them, e θi (i=1,2,3) represents the basis vectors of the local coordinate system after rotation.

[0065] Specifically, the curvilinear coordinate system module is established based on the Navier-Stokes equation, which is used to describe the dynamic equilibrium relationship of forces in any region of the fluid. For composite materials with complex structures, from a microscopic perspective, each fiber is folded into a curved shape, and the mechanical properties of the material change with the bending direction of the fiber, that is, from a macroscopic perspective, the mechanical properties of the composite material change along the tangent and normal directions of the curved surface. Therefore, the fibers inside the composite material are assumed to be curved tubes with curvature, with a fluid at a constant speed passing through the middle. When the fluid flows in the tube and reaches a steady state, the velocity direction of the fluid in the curved tube is the axial direction of the fiber. Therefore, the streamline equation is used to construct the local coordinate system of the composite material. The streamline equation can be obtained by the Euler differential equation of motion, and the streamline equation of the fluid in the curved tube is determined according to the expression defined below.

[0066] Fluid flow control conditions:

[0067]

[0068] Pipe wall constraints:

[0069] u·n=0

[0070] Entrance:

[0071] u·n=u n

[0072] exit:

[0073]

[0074] Where v is the direction vector of the streamline, u is the velocity vector, is the differential operator, p is the pressure, n is the normal vector, u n is the normal velocity.

[0075] The local coordinate system of the composite material structure is constructed according to the streamline equation. The unit vector perpendicular to the fiber direction is solved based on the fiber axis direction obtained from the streamline equation. The expression is as follows:

[0076]

[0077] Among them, e1 is the unit vector along the axial direction of the fiber, e2 and e3 are the unit vectors perpendicular to the axial direction of the fiber, and m is the basis vector of the second coordinate system.

[0078] Furthermore, the thermal-chemical-mechanical-fluid-solid multi-field coupling model in S2 includes a thermal-chemical coupling temperature field calculation model, a thermal-mechanical coupling stress field calculation model and a fluid-solid coupling model;

[0079] The thermal-chemical coupled temperature field calculation model includes a heat conduction model and a curing kinetics model;

[0080] A thermal-mechanical coupling stress field calculation model is established based on the stress-strain relationship, thermal expansion of the resin and the curing shrinkage effect;

[0081] The fluid-structure interaction model is represented based on mass conservation, resin flow continuity, and Darcy's law.

[0082] Specifically, the heat conduction model is based on the heat conduction equation of the coupled curing exothermic term:

[0083]

[0084] Where K xx , K yy and K zz are the thermal conductivity coefficients of the material in each direction, T is the curing reaction temperature in the current time domain and space domain, ρ c and C c are the density and specific heat capacity of the composite material, It represents the endogenous term of resin exotherm during the curing reaction.

[0085] Furthermore, the expression of the thermal-chemical coupled temperature field calculation model is:

[0086]

[0087] Wherein, m and n represent the curing reaction order, and K0 represents the reaction rate constant;

[0088] The expression of the thermal-mechanical coupling stress field calculation model is:

[0089] σ=Cε

[0090] ε=ε e +ε th +ε sh

[0091] Where, σ represents the curing stress, C represents the composite stiffness matrix, ε represents the curing strain, and ε e represents the elastic strain, ε th represents the thermal expansion strain, ε sh represents the curing shrinkage strain;

[0092] The expression of the fluid-structure coupling model is:

[0093]

[0094] P a =P+σ f

[0095] Among them, S ii(i＝x,y,z) represents the fiber bed permeability, μ represents the resin viscosity, P represents the resin pressure, ε v represents volumetric strain, σ f represents the effective stress of the fiber, P a Indicates that external load is applied.

[0096] Specifically, the physical fields determined in S2 include temperature field, curing rate and curing degree field.

[0097] Furthermore, the parameters defined in S2 include thermodynamic performance parameters, time-varying characteristic expressions, and curing process curves;

[0098] Thermodynamic performance parameters include thermal performance parameters and mechanical performance parameters. Thermal performance parameters include thermal conductivity and specific heat capacity. Mechanical performance parameters include modulus, Poisson's ratio, density, fiber volume fraction, and thermal expansion coefficient.

[0099] The material property expression based on the law of mixtures is:

[0100] ρ c =V f ρ f +V m ρ m

[0101] C c =V f C f +V m C m

[0102] Wherein, f represents fiber, m represents resin, V represents volume fraction, ρ represents density, and C represents specific heat capacity;

[0103] The expression based on the time-varying properties of the material is:

[0104]

[0105] Where E m 、v m and G m They represent the elastic modulus, Poisson's ratio and shear modulus of the resin respectively. and Respectively represent the elastic modulus of the resin at the beginning and end of curing, α gel Indicates the degree of solidification at the gel point, α mod It is a function of the degree of cure and the gel point.

[0106] Furthermore, the variable modules in S2 include a curvilinear coordinate module, a solid heat transfer module, a coefficient form partial differential equation module, a Darcy's law module, and a solid mechanics module.

[0107] Furthermore, a thermal-chemical-mechanical-fluid-solid multi-field coupling model was constructed based on the COMSOL platform.

[0108] In a specific embodiment, the fibers in the complex structure composite are assumed to be curved pipes, and the curvilinear coordinate module is used to simulate the process. The local coordinate system basis vectors of the 0° ply are calculated based on the streamline equation. In the coordinate system setting, the composite coordinate system is used, and the required curvilinear coordinate system basis vectors are used as the basic coordinate system. The corresponding ply angles are set in the rotating coordinate system to complete the definition of the local coordinate system of the single-layer composite with different ply directions.

[0109] For the local coordinate system of single-layer composite materials in different ply directions, the solution is obtained by combining curvilinear coordinates, rotational coordinates and composite coordinates, including:

[0110] (1) The curvilinear coordinate module is used to calculate the local coordinate system basis vectors of the 0° ply based on the streamline equation.

[0111] Basic vector fluid flow control conditions:

[0112]

[0113] Pipe wall constraints:

[0114] u·n=0

[0115] Entrance:

[0116] u·n=u n

[0117] exit:

[0118]

[0119] Where v is the direction vector of the streamline, u is the velocity vector, is the differential operator, p is the pressure, n is the normal vector, u n is the normal velocity.

[0120] (2) Based on the basis vector in the fiber axis direction obtained from the streamline equation, the basis vectors in the other two directions perpendicular to the fiber are calculated. The expressions are as follows:

[0121]

[0122] Among them, e1 is the unit vector along the axial direction of the fiber, e2 and e3 are the unit vectors perpendicular to the axial direction of the fiber, and m is the basis vector of the second coordinate system. In this example, the width direction of the L piece is used.

[0123] The thermal-chemical-mechanical-fluid-solid multi-field coupling model of the composite material curing process with different parameters is constructed in COMSOL, and the prediction of the molding defects of composite material components with different layup parameters is completed according to the composite material curing process. Figure 2 As shown in Figure 1, the thermal-chemical-mechanical-fluid-solid multi-field coupling model specifically includes:

[0124] The model consists of multiple physical fields and can be divided into three modules: thermal-chemical coupling temperature field calculation model, thermal-mechanical coupling stress field calculation model and fluid-solid coupling model. First, with the original material parameters as input, the heat transfer equation and curing kinetics equation are solved in the thermal-chemical coupling temperature field calculation model to obtain the distribution of non-uniform temperature field and curing degree field. Subsequently, all time-varying parameters related to the rheological and mechanical properties of fiber, resin and composite material are updated using the output of the thermal-chemical coupling temperature field calculation model. On the basis of calculating rheological parameters such as resin viscosity and permeability, the resin flow and fiber compaction behavior are analyzed based on effective stress theory and Darcy's law. Then, the resin pressure is updated to obtain a new fiber volume fraction distribution. The fiber volume fraction calculated by the fluid-solid coupling model is then input into the thermal-mechanical coupling stress field calculation model, and the non-uniform curing residual stress field is calculated based on the updated mechanical property parameters. At the same time, the new fiber volume fraction is also input into the thermal-chemical coupling temperature field calculation model for a new round of temperature field calculation. This iterative process continues until the composite material is fully cured. Through this multi-field coupling calculation strategy, the evolution of temperature and curing degree can be obtained, thereby predicting the distribution of residual stress, fiber volume fraction and non-uniform thickness.

[0125] Single-layer composite materials with different laying directions need to set the coordinate systems of solid, fluid and matrix properties and linear elastic materials in the corresponding modules respectively, and select the corresponding local coordinate system as the input of coordinate system selection to realize the setting of local coordinate system of unidirectional composite materials with different laying directions, thereby completing the assignment of anisotropic material properties in single-layer composite materials.

[0126] The expression of the basis vector after rotation is:

[0127]

[0128] Among them, α, β and γ are the rotation angles around the initial basis vectors in three directions respectively. In this embodiment, the ply rotation angle with a ply angle of θ is:

[0129]

[0130] Therefore, the expression of the rotated basis vector is simplified to:

[0131]

[0132] Among them, e θi (i=1,2,3) represents the local coordinate system basis vector after rotation. The anisotropic material properties of the single-layer composite material with different plies are assigned according to the direction of the corresponding local coordinate system basis vector.

[0133] In another specific embodiment, the prediction of molding defects of L composite materials with different layup parameters during curing is taken as an example to demonstrate the technical effect. In this embodiment, a curing multi-field coupling analysis is performed to obtain the final molding defects of L composite materials with different layup parameters. The specific process includes the following steps:

[0134] Step 1: Create Figure 3 The three-dimensional finite element model of the L-shaped structural member shown in Figure 4 The load boundary conditions of the L-shaped part shown in the figure are given by the refined grid division and the material layup method is shown in Table 1.

[0135] Table 1 Laying parameters of L-shaped composite materials for three groups of cross-ply

[0136] serial number Laying parameters CP-1 <![CDATA[[03 / 90 / 03 / 90 / 02] s ]]> CP-2 <![CDATA[[0 / 902 / 0 / 903 / 0 / 902] s ]]> CP-3 <![CDATA[[0 / 454 / 90 / -454] s ]]>

[0137] Step 2: Calculate the curvilinear coordinate module to solve the local coordinate system of the composite material with a ply angle of 0°. Then, the local coordinate system of the composite material with any ply angle θ is solved by combining the curvilinear coordinate system and the rotating coordinate system through the composite coordinate system. The result is as follows: Figure 5 shown.

[0138] Step 3: Input the thermodynamic performance parameters of the composite material and each component material and the expressions characterizing their time-varying characteristics into the parameter and variable settings respectively. Set the coordinate system of solid, fluid and matrix properties and linear elastic materials in the corresponding modules including solid heat transfer module, Darcy's law module and solid mechanics module, complete the setting of local coordinate system of composite materials in different ply directions, and thus realize the setting of anisotropic material properties.

[0139] Step 4: Input the curing temperature T into the solid heat transfer module and combine it with the coefficient form partial differential equation module that characterizes the curing kinetic equation to calculate the non-uniform temperature field and curing degree field. Position labeling of composite L-shaped parts with different layup parameters Figure 6 As shown in the figure, combined with the updated thermodynamic performance parameters, Darcy's law module and solid mechanics module are solved to predict the thickness tolerance and uneven glue content of L-shaped composite parts with different layup parameters. The prediction results are shown in Figure 7 and Figure 8 shown.

[0140] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0141] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL, characterized in that: The following steps are involved: S1. Initialize a finite element model according to the geometric dimensions of the composite structure, obtain a local coordinate system of the composite structure using the finite element model, calibrate the ply direction, and establish a local coordinate system of different ply directions according to the rotating coordinate system; S2. Based on the thermal-chemical-mechanical-fluid-solid multi-field coupling model, determine the physical field and use the definition parameters of the composite structure in the calculation process as the input of the variable module; S3. Based on the thermal-chemical-mechanical-fluid-solid multi-field coupling model, the load boundary conditions are set, and each ply is placed in the local coordinate system of different ply directions established in S1 according to the ply direction, and the curing defects of composite structural parts with different ply parameters are calculated.

2. According to claim 1, a multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL is characterized in that: In S1, the curvilinear coordinate system module is used to obtain the local coordinate system of the composite structure, calibrate the 0° ply direction for laying according to the geometric shape, and calculate the local coordinate system of the single-layer composite material with different ply angles using the rotating coordinate system transformation.

3. The multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL according to claim 2 is characterized in that: The curvilinear coordinate system module is established based on the Navier-Stokes equation, and the local coordinate system of the composite structure is constructed based on the streamline equation; the local coordinate system of the single-layer composite material with different ply angles is calculated by the rotation coordinate system conversion. When the ply angle is θ, the local coordinate system of the single-layer composite material is first defined by rotating the θ angle rotation coordinate system. The expression of the coordinate transformation of the rotation coordinate system is as follows: Among them, v i (i=x,y,z) represents the coordinates after rotation, v i (i=X,Y,Z) represents the coordinates before rotation; Based on the curvilinear coordinate system solved by the rotating coordinate system and the streamline equation, the composite coordinate system is used to define the local coordinate system in the ply direction other than 0°. The composite coordinate system acts as a continuous application of two independent coordinate systems. The curvilinear coordinate system is set as the basic system coordinate system, that is, the basis vector is defined, and the rotating coordinate system is set as the relative coordinate system, that is, the rotation matrix of the angle ply is defined. The expression of the coordinate transformation of the composite coordinate system is as follows: Among them, e θi (i=1,2,3) represents the basis vectors of the local coordinate system after rotation.

4. The multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL according to claim 1 is characterized in that: The thermal-chemical-mechanical-fluid-solid multi-field coupling model in S2 includes a thermal-chemical coupling temperature field calculation model, a thermal-mechanical coupling stress field calculation model and a fluid-solid coupling model; The thermal-chemical coupled temperature field calculation model includes a heat conduction model and a curing kinetics model; A thermal-mechanical coupling stress field calculation model is established based on the stress-strain relationship, thermal expansion of the resin and the curing shrinkage effect; The fluid-structure interaction model is represented based on mass conservation, resin flow continuity, and Darcy's law.

5. The multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL according to claim 4 is characterized in that: The expression of the thermal-chemical coupled temperature field calculation model is: Wherein, m and n represent the curing reaction order, and K0 represents the reaction rate constant; The expression of the thermal-mechanical coupling stress field calculation model is: σ=Cε e=e e +e th +e sh Where, σ represents the curing stress, C represents the composite stiffness matrix, ε represents the curing strain, and ε e represents the elastic strain, ε th represents the thermal expansion strain, ε sh represents the curing shrinkage strain; The expression of the fluid-structure coupling model is: P a =P+σ f Among them, S ii(i＝x,y,z) represents the fiber bed permeability, μ represents the resin viscosity, P represents the resin pressure, ε v represents volumetric strain, σ f represents the effective stress of the fiber, P a Indicates that external load is applied.

6. The multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL according to claim 1 is characterized in that: The parameters defined in S2 include thermodynamic performance parameters, time-varying characteristic expressions, and curing process curves; Thermodynamic performance parameters include thermal performance parameters and mechanical performance parameters. Thermal performance parameters include thermal conductivity and specific heat capacity. Mechanical performance parameters include modulus, Poisson's ratio, density, fiber volume fraction, and thermal expansion coefficient. The material property expression based on the law of mixtures is: r c =V f r f +V m r m C c =V f C f +V m C m Among them, f represents fiber, m represents resin, V represents volume fraction, ρ represents density, and C represents specific heat capacity; The expression based on the time-varying properties of the material is: Where E m 、v m and G m They represent the elastic modulus, Poisson's ratio and shear modulus of the resin respectively. and Respectively represent the elastic modulus of the resin at the beginning and end of curing, α gel Indicates the degree of solidification at the gel point, α mod It is a function of the degree of cure and the gel point.

7. The multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL according to claim 1 is characterized in that: The variable modules in S2 include curvilinear coordinate module, solid heat transfer module, coefficient form partial differential equation module, Darcy's law module, and solid mechanics module.

8. The multi-field coupling simulation modeling method for composite material curing with different ply parameters based on COMSOL according to claim 1 is characterized in that: A thermal-chemical-mechanical-fluid-solid multi-field coupling model was constructed based on the COMSOL platform.

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