A COMSOL-based simulation modeling method for multi-field coupling of composite curing with different layup parameters
By using COMSOL's multi-field coupling simulation modeling method, the problem of predicting molding defects during the curing process of fiber-reinforced composite materials was solved, and efficient and accurate prediction and optimization of molding defects in composite structural parts were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NORTHWESTERN POLYTECHNICAL UNIV
- Filing Date
- 2024-09-11
- Publication Date
- 2026-07-21
Smart Images
Figure CN119170169B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of composite material curing and molding simulation and prediction technology, and in particular to a multi-field coupled simulation modeling method for composite material curing with different layup parameters based on COMSOL. Background Technology
[0002] Fiber-reinforced composites, due to their high specific strength and specific stiffness, can significantly reduce the mass of structural components. Furthermore, the fibers can be designed and arranged according to the load path to meet the strength and stiffness requirements of the structure. However, after the curing process, the demolding of fiber-reinforced composites often results in some difference from the initial design shape. Although the prepreg is laid according to the mold shape during the layup stage, the anisotropy of the composite's thermodynamic properties, its coefficient of thermal expansion, curing shrinkage rate, interlayer stiffness, and layup direction, as well as the flow and compaction process of the resin under external load, all significantly affect the curing results. This can lead to wrinkling, thickness deviations, uneven resin content, and non-uniform curing residual stress, thereby reducing manufacturing precision.
[0003] With the increasing demands for stability and precision in the production process of composite structural components in the aerospace and automotive industries, traditional trial-and-error methods for automated manufacturing are costly, inefficient, and lack controllability, making it difficult to achieve higher manufacturing efficiency and ensure reproducible molded part quality. Therefore, finite element analysis (FEM) is needed to characterize and model this process to predict and optimize molding defects before the composite structural component molding process. Since fiber orientation, i.e., the layup parameters of the composite structural component, is closely related to the rigidity and strength of the molded part and the generation of molding defects, COMSOL, as an efficient multiphysics simulation tool, faces two challenges in establishing a multi-directional layup composite curing simulation model: characterizing the multi-directional layup and establishing a three-dimensional curing multi-field coupling model. Accurately characterizing the composite curing process considering layup parameters and effectively predicting curing defects are key factors in understanding the mechanism of curing defect generation and effectively controlling molding defects.
[0004] Therefore, proposing a multi-field coupled simulation modeling method for curing composite materials with different layup parameters based on COMSOL to solve the difficulties of existing technologies is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0005] In view of this, the present invention provides a multi-field coupled simulation modeling method for curing composite materials with different layup parameters based on COMSOL, which realizes 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 molding defects of complex structural composite materials.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A multi-field coupled simulation modeling method for curing composite materials with different layup parameters based on COMSOL includes the following steps:
[0008] S1. Initialize the finite element model based on the geometric dimensions of the composite material structure, obtain the local coordinate system of the composite material structure using the finite element model, calibrate the ply direction, and establish local coordinate systems for different ply directions based on the rotating coordinate system;
[0009] S2. Based on the thermo-chemical-mechanical-fluid-structure interaction model, the physical field is determined, and the defined parameters of the composite material structure are used as inputs to the variable module during the calculation process;
[0010] S3. Based on the thermo-chemical-mechanical-fluid-solid multi-field coupling model, load boundary conditions are set, and each ply is set in a local coordinate system with different ply directions established in S1 according to the ply direction. The curing defects of composite material structural parts with different ply parameters are calculated.
[0011] Optionally, in the above method, the local coordinate system of the composite material structure is obtained by using the curve coordinate system module in S1, the 0° lay-up direction of the layer laid according to the geometric shape is calibrated, and the local coordinate system of the single-layer composite material with different lay-up angles is calculated by using the rotation coordinate system transformation.
[0012] Optionally, the above method involves establishing a curve coordinate system module based on the Navier-Stokes equations and constructing a local coordinate system for composite material structures based on streamline equations. The local coordinate system of a single-layer composite material with different ply angles is calculated using a rotation coordinate system transformation. For the local coordinate system of a single-layer composite material with a ply angle of θ, a rotation coordinate system with a rotation angle of θ is first defined. The expression for the coordinate transformation of the rotation coordinate system is as follows:
[0013]
[0014] Among them, v i (i = x, y, z) represents the rotated coordinates, v i (i = X, Y, Z) represents the coordinates before rotation;
[0015] Based on the curved coordinate system obtained from the rotation coordinate system and streamline equations, a composite coordinate system is used to define the local intra-layer coordinate system for non-0° ply directions. The composite coordinate system acts as a continuous application of two independent coordinate systems. The curved coordinate system is set as the basic system coordinate system, i.e., the basis vectors are defined, and the rotation coordinate system is set as the relative coordinate system, i.e., the rotation matrix of the angular ply is defined. The expression for the coordinate transformation of the composite coordinate system is as follows:
[0016]
[0017] Among them, e θi (i = 1, 2, 3) represents the basis vector of the local coordinate system after rotation.
[0018] Optionally, the thermo-chemical-mechanical-fluid-structure interaction (S2) multi-field coupling model includes a thermo-chemical coupling temperature field calculation model, a thermo-mechanical coupling stress field calculation model, and a fluid-structure interaction model.
[0019] The thermal-chemical coupling temperature field calculation model includes a heat conduction model and a curing kinetics model;
[0020] A thermo-mechanical coupled stress field calculation model is established based on the stress-strain relationship, the thermal expansion of the resin and the curing shrinkage effect.
[0021] The fluid-structure interaction model is based on the principles of mass conservation, resin flow continuity, and Darcy's law.
[0022] The above method, optionally, provides the following expression for the thermal-chemical coupling temperature field calculation model:
[0023]
[0024] Where m and n represent the order of the curing reaction, and K0 represents the reaction rate constant;
[0025] The expression for the thermo-mechanical coupled stress field calculation model is as follows:
[0026] σ=Cε
[0027] ε=ε e +ε th +ε sh
[0028] Where σ represents curing stress, C represents the composite material stiffness matrix, and ε represents curing strain. e ε represents elastic strain. th ε represents thermal expansion strain. th Indicates the curing shrinkage strain;
[0029] The expression for the fluid-structure interaction model is:
[0030]
[0031] P a =P+σ f
[0032] Among them, S ii(i＝x,y,z) The fiber bed permeability is represented by μ, the resin viscosity by P, and the resin pressure by ε. v σ represents volumetric strain. f P represents the effective stress of the fiber. aThis indicates the application of an external load.
[0033] Optionally, in the above method, 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, while mechanical performance parameters include modulus, Poisson's ratio, density, fiber volume fraction, and coefficient of thermal expansion.
[0035] The material property expression based on the hybrid law is:
[0036] ρ c =V f ρ f +V m ρ m
[0037] C c =V f C f +V m C m
[0038] Where 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 These represent the resin's elastic modulus, Poisson's ratio, and shear modulus, respectively. and α represents the elastic modulus of the resin at the beginning and end of curing, respectively. gel α represents the degree of curing at the gel point. mod It is a function of curing degree and gel point.
[0042] The above method can optionally include the following variable modules in S2: curve coordinate module, solid heat transfer module, coefficient form partial differential equation module, Darcy's law module, and solid mechanics module.
[0043] Optionally, the above method can be used to construct a thermo-chemical-mechanical-fluid-structure interaction model based on the COMSOL platform.
[0044] As can be seen from the above technical solution, compared with the prior art, the present invention provides a multi-field coupled simulation modeling method for curing composite materials with different layup parameters based on COMSOL, which has the following beneficial effects: The present invention not only realizes the establishment of a multi-field coupled model of the curing process of heat-chemical-mechanical-fluid-solid process, but also provides a composite material modeling method with different layup parameters based on COMSOL software. It can realize the prediction of molding defects of composite material structures with different layup parameters, and provides a new modeling idea for the accurate prediction of molding defects of complex composite materials. It has important guiding significance for reducing curing defects by optimizing layup parameters, thereby preparing high-performance composite material structures. Attached Figure Description
[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0046] Figure 1 A flowchart of a multi-field coupled simulation modeling method for curing composite materials with different layup parameters based on COMSOL is provided for this invention.
[0047] Figure 2 Flowchart of the thermo-chemical-mechanical-fluid-structure interaction multi-field coupling model provided by this invention;
[0048] Figure 3 This is a schematic diagram of the finite element mesh generation for the L-shaped component provided by the present invention;
[0049] Figure 4 This is a schematic diagram of the load boundary conditions for the L-shaped component provided by the present invention;
[0050] Figure 5 This is a schematic diagram of the local coordinate system setting for prepregs with different layup directions provided by the present invention;
[0051] Figure 6 This invention provides a diagram showing the numbering of L-shaped parts with different layup parameters.
[0052] Figure 7 A schematic diagram showing the thickness variation of L-shaped parts with different layup parameters provided by the present invention;
[0053] Figure 8 This is a schematic diagram showing the non-uniform resin content distribution in the corner area of an L-shaped part with different layup parameters provided by the present invention. Detailed Implementation
[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0055] Reference Figure 1 As shown, this invention discloses a multi-field coupled simulation modeling method for curing composite materials with different layup parameters based on COMSOL, including the following steps:
[0056] S1. Initialize the finite element model based on the geometric dimensions of the composite material structure, obtain the local coordinate system of the composite material structure using the finite element model, calibrate the ply direction, and establish local coordinate systems for different ply directions based on the rotating coordinate system;
[0057] S2. Based on the thermo-chemical-mechanical-fluid-structure interaction model, the physical field is determined, and the defined parameters of the composite material structure are used as inputs to the variable module during the calculation process;
[0058] S3. Based on the thermo-chemical-mechanical-fluid-solid multi-field coupling model, load boundary conditions are set, and each ply is set in a local coordinate system with different ply directions established in S1 according to the ply direction. The curing defects of composite material structural parts with different ply parameters are calculated.
[0059] Furthermore, a curve coordinate system module is established based on the Navier-Stokes equations, and a local coordinate system for composite material structures is constructed based on the streamline equations. The local coordinate system of a single-layer composite material with different ply angles is calculated using a rotation coordinate system transformation. For the local coordinate system of a single-layer composite material with a ply angle of θ, a rotation coordinate system with a rotation angle of θ is first defined. 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 rotated coordinates, v i (i = X, Y, Z) represents the coordinates before rotation;
[0062] Based on the curved coordinate system obtained from the rotation coordinate system and streamline equations, a composite coordinate system is used to define the local intra-layer coordinate system for non-0° ply directions. The composite coordinate system acts as a continuous application of two independent coordinate systems. The curved coordinate system is set as the basic system coordinate system, i.e., the basis vectors are defined, and the rotation coordinate system is set as the relative coordinate system, i.e., the rotation matrix of the angular ply is defined. The expression for the coordinate transformation of the composite coordinate system is as follows:
[0063]
[0064] Among them, e θi (i = 1, 2, 3) represents the basis vector of the local coordinate system after rotation.
[0065] Specifically, the curved coordinate system module is established based on the Navier-Stokes equations, which describe the dynamic equilibrium of forces within an arbitrary region of a fluid. For complex composite materials, from a microscopic perspective, each fiber is bent 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 a constant velocity of fluid flowing through them. When the fluid flow reaches a steady state inside the tube, the velocity direction of the fluid in the curved tube is the axial direction of the fiber. Therefore, streamline equations are used to construct the local coordinate system of the composite material. The streamline equations can be obtained through Euler's differential equations of motion, and the streamline equations of the fluid inside the curved tube are determined according to the following defined expression.
[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, and u is the velocity vector. Here, p is the differential operator, n is the pressure, and u is the normal vector. n This represents the normal velocity.
[0075] A local coordinate system for the composite material structure is constructed based on the streamline equation. The unit vector perpendicular to the fiber direction is then calculated based on the fiber axis direction obtained from the streamline equation, as shown in the following expression:
[0076]
[0077] Where e1 is a unit vector along the fiber axis, e2 and e3 are unit vectors perpendicular to the fiber axis, and m is the basis vector of the second coordinate system.
[0078] Furthermore, the thermo-chemical-mechanical-fluid-structure interaction multi-field coupling model in S2 includes a thermo-chemical coupling temperature field calculation model, a thermo-mechanical coupling stress field calculation model, and a fluid-structure interaction model.
[0079] The thermal-chemical coupling temperature field calculation model includes a heat conduction model and a curing kinetics model;
[0080] A thermo-mechanical coupled stress field calculation model is established based on the stress-strain relationship, the thermal expansion of the resin and the curing shrinkage effect.
[0081] The fluid-structure interaction model is based on the principles of mass conservation, resin flow continuity, and Darcy's law.
[0082] Specifically, the heat conduction model based on the heat conduction equation of the coupled curing exothermic term is as follows:
[0083]
[0084] Where K xx K yy and K zz These are the thermal conductivity coefficients of the material along each direction, T is the curing reaction temperature in the current time and space domains, and ρ is the thermal conductivity coefficient of the material along each direction. c and C c These are the density and specific heat capacity of the composite material, respectively. This represents the exothermic internal term of the resin during the curing reaction.
[0085] Furthermore, the expression for the thermal-chemical coupled temperature field calculation model is as follows:
[0086]
[0087] Where m and n represent the order of the curing reaction, and K0 represents the reaction rate constant;
[0088] The expression for the thermo-mechanical coupled stress field calculation model is as follows:
[0089] σ=Cε
[0090] ε=ε e +ε th +ε sh
[0091] Where σ represents curing stress, C represents the composite material stiffness matrix, and ε represents curing strain. e ε represents elastic strain. th ε represents thermal expansion strain. sh Indicates the curing shrinkage strain;
[0092] The expression for the fluid-structure interaction model is:
[0093]
[0094] P a =P+σ f
[0095] Among them, S ii(i＝x,y,z) The fiber bed permeability is represented by μ, the resin viscosity by P, and the resin pressure by ε. v σ represents volumetric strain. f P represents the effective stress of the fiber. a This indicates the application of an external load.
[0096] Specifically, the physical fields defined in S2 include the 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, while mechanical performance parameters include modulus, Poisson's ratio, density, fiber volume fraction, and coefficient of thermal expansion.
[0099] The material property expression based on the hybrid law is:
[0100] ρ c =V f ρ f +V m ρ m
[0101] C c =V f C f +V m C m
[0102] Where 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 These represent the resin's elastic modulus, Poisson's ratio, and shear modulus, respectively. and α represents the elastic modulus of the resin at the beginning and end of curing, respectively. gel α represents the degree of curing at the gel point. mod It is a function of curing degree and gel point.
[0106] Furthermore, the variable modules in S2 include a curve 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 multi-field coupled model of thermo-chemical-mechanical-fluid-solid dynamics was constructed based on the COMSOL platform.
[0108] In a specific embodiment, the fibers in the complex structural composite are imagined as curved pipes, and the process is simulated using a curve coordinate module. The local coordinate system basis vector of the 0° layup is calculated based on the streamline equation. In the coordinate system setting, a composite coordinate system is used, and the calculated curve coordinate system basis vector is used as the basic coordinate system. The corresponding layup angle is set in the rotating coordinate system to complete the definition of the local coordinate system of the single-layer composite with different layup directions.
[0109] For the local coordinate system of single-layer composites with different ply directions, a combination of curvilinear coordinates, rotated coordinates, and composite coordinates is used to solve the problem, specifically including:
[0110] (1) Using the curve coordinate module, the local coordinate system basis vector of 0° ply is calculated 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, and u is the velocity vector. Here, p is the differential operator, n is the pressure, and u is the normal vector. n This represents the normal velocity.
[0120] (2) Based on the fiber axis direction basis vector obtained from the streamline equation, calculate the basis vectors perpendicular to the fiber in the other two directions, as shown in the following expressions:
[0121]
[0122] Where e1 is a unit vector along the fiber axis, e2 and e3 are unit vectors perpendicular to the fiber axis, and m is the basis vector of the second coordinate system. In this example, the width direction of the L piece is used.
[0123] This study utilizes COMSOL to construct multi-field coupled thermo-chemical-mechanical-fluid-structure interaction models of composite material curing processes with different parameters. Based on these models, it aims to predict molding defects in composite material components with different layup parameters during the curing process. Figure 2 As shown, the thermo-chemical-mechanical-fluid-structure interaction model specifically includes:
[0124] The model consists of multiple physical fields and can be divided into three modules: a thermo-chemical coupled temperature field calculation model, a thermo-mechanical coupled stress field calculation model, and a fluid-structure interaction model. First, using the original material parameters as input, the heat transfer equation and curing kinetics equation are solved in the thermo-chemical coupled temperature field calculation model to obtain the distribution of the non-uniform temperature field and degree of cure field. Then, using the output of the thermo-chemical coupled temperature field calculation model, all time-varying parameters related to the rheological and mechanical properties of the fiber, resin, and composite material are updated. Based on the calculation of rheological parameters such as resin viscosity and permeability, the resin flow and fiber compressive 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. Next, the fiber volume fraction calculated by the fluid-structure interaction model is input into the thermo-mechanical coupled stress field calculation model, and based on the updated mechanical property parameters, the non-uniform curing residual stress field is calculated. Simultaneously, the new fiber volume fraction is also input into the thermo-chemical coupled temperature field calculation model for a new round of temperature field calculations. This iterative process continues until the composite material is completely cured. This multi-field coupling calculation strategy allows us to obtain the evolution of temperature and degree of curing, thereby predicting the distribution of residual stress, fiber volume fraction, and non-uniform thickness.
[0125] For single-layer composite materials with different layup directions, it is necessary to set the coordinate systems of solid, fluid, and matrix properties and linear elastic materials in the corresponding modules respectively. The corresponding local coordinate system is selected as the input for coordinate system selection to realize the setting of the local coordinate system of unidirectional composite materials with different layup directions, thereby completing the assignment of anisotropic material properties in single-layer composite materials.
[0126] The expression for the rotated basis vectors:
[0127]
[0128] Where α, β, and γ are rotation angles around the initial basis vectors in the three directions, respectively. In this embodiment, the ply rotation angle with a ply angle of θ is:
[0129]
[0130] Therefore, the expression for the rotated basis vectors simplifies to:
[0131]
[0132] Among them, e θi (i = 1, 2, 3) represents the local coordinate system basis vector after rotation. The anisotropic material properties within single-layer composite materials with different layups are assigned according to the direction of the corresponding local coordinate system basis vector.
[0133] In another specific embodiment, the technical effect is demonstrated by taking the prediction of molding defects in L-shaped composite materials with different layup parameters after curing. In this embodiment, a multi-field coupling analysis of curing was performed to obtain the final molding defects of L-shaped composite materials with different layup parameters. The specific process includes the following steps:
[0134] Step 1: Establish as follows Figure 3 The three-dimensional finite element model of the L-shaped structural component shown and Figure 4 The load boundary conditions for the L-shaped component are shown in Table 1, with a given refined mesh and material layup method.
[0135] Table 1. Layup parameters of L-shaped composite materials with three cross-layouts.
[0136] 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 at a 0° ply angle. Then, by combining the composite coordinate system with the curvilinear coordinate system and the rotated coordinate system, complete the solution for the local coordinate system of the composite material at any ply angle θ. The result is as follows: Figure 5 As shown.
[0138] Step 3: Input the thermodynamic property parameters of the composite material and each component material, along with the expressions characterizing their time-varying properties, into the parameter and variable settings respectively. Then, in the corresponding modules, including the solid heat transfer module, Darcy's law module, and solid mechanics module, set the coordinate systems for solid, fluid, and matrix properties, as well as for linear elastic materials. This completes the setting of the local coordinate systems for composite materials with different layup directions, thereby achieving 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 characterizing the curing kinetics equation to calculate the non-uniform temperature field and curing degree field. Position labels for L-shaped composite parts with different layup parameters. Figure 6 As shown, by combining the updated thermodynamic property parameters, the Darcy's law module and the solid mechanics module are solved to predict the thickness deviation and uneven glue content molding defects of composite L-shaped parts with different layup parameters. The prediction results are as follows. Figure 7 and Figure 8 As shown.
[0140] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0141] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A multi-field coupled simulation modeling method for curing composite materials with different layup parameters based on COMSOL, characterized in that, Includes the following steps: S1. Initialize the finite element model based on the geometric dimensions of the composite material structure, obtain the local coordinate system of the composite material structure using the finite element model, calibrate the ply direction, and establish local coordinate systems for different ply directions based on the rotating coordinate system; S2. Based on the thermo-chemical-mechanical-fluid-structure interaction model, the physical field is determined, and the defined parameters of the composite material structure are used as inputs to the variable module during the calculation process; S3. Based on the thermo-chemical-mechanical-fluid-solid multi-field coupling model, load boundary conditions are set, and each ply is set in a local coordinate system with different ply directions established in S1 according to the ply direction. The curing defects of composite material structural parts with different ply parameters are calculated. In S1, the curve coordinate system module is used to obtain the local coordinate system of the composite material structural component and calibrate the laying according to the geometric shape. For the ply direction, the local coordinate system of single-layer composites with different ply angles is calculated by using a rotating coordinate system transformation; A curve coordinate system module is established based on the Navier-Stokes equations, and a local coordinate system for composite material structures is constructed based on streamline equations. The local coordinate system of single-layer composites with different ply angles is calculated using coordinate system transformation. When the ply angle is... The local coordinate system of the single-layer composite material at that time is first defined by rotation. The expression for coordinate transformation in a rotating coordinate system is as follows: in, Represents the coordinates after rotation. Represents the coordinates before rotation; Based on the curved coordinate system obtained from the rotation coordinate system and streamline equations, a composite coordinate system is used to define the local intra-layer coordinate system for non-0° ply directions. The composite coordinate system acts as a continuous application of two independent coordinate systems. The curved coordinate system is set as the basic system coordinate system, i.e., the basis vectors are defined, and the rotation coordinate system is set as the relative coordinate system, i.e., the rotation matrix of the angular ply is defined. The expression for the coordinate transformation of the composite coordinate system is as follows: in, Represents the basis vectors of the rotated local coordinate system; The S2 thermo-chemical-mechanical-fluid-structure multi-field coupling model includes a thermo-chemical coupling temperature field calculation model, a thermo-mechanical coupling stress field calculation model, and a fluid-structure coupling model; The thermal-chemical coupling temperature field calculation model includes a heat conduction model and a curing kinetics model; A thermo-mechanical coupled stress field calculation model is established based on the stress-strain relationship, the thermal expansion of the resin and the curing shrinkage effect. The fluid-structure interaction model is based on mass conservation, resin flow continuity, and Darcy's law. The expression for the thermal-chemical coupling temperature field calculation model is as follows: in, m and n Indicates the order of the curing reaction. Represents the reaction rate constant; The expression for the thermo-mechanical coupled stress field calculation model is as follows: in, Indicates curing stress. Represents the stiffness matrix of composite materials. Indicates curing strain. Indicates elastic strain. Indicates thermal expansion strain. Indicates the curing shrinkage strain; The expression for the fluid-structure interaction model is: in, Indicates fiber bed permeability. Indicates resin viscosity. Indicates resin pressure. Indicates volumetric strain. Indicates the effective stress of the fiber. This indicates the application of an external load.
2. The method for multi-field coupled simulation modeling of composite material curing with different layup parameters based on COMSOL, as described in 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, while mechanical performance parameters include modulus, Poisson's ratio, density, fiber volume fraction, and coefficient of thermal expansion. The material property expression based on the hybrid law is: in, Indicates fiber, Represents resin. Represents volume fraction. Indicates density, Indicates specific heat capacity; The expression based on the time-varying properties of the material is: in , and These represent the resin's elastic modulus, Poisson's ratio, and shear modulus, respectively. and These represent the elastic modulus of the resin at the beginning and end of curing, respectively. This indicates the degree of curing at the gel point. It is a function of curing degree and gel point.
3. The method for multi-field coupled simulation modeling of composite material curing with different layup parameters based on COMSOL, as described in claim 1, is characterized in that... The variable modules in S2 include the curvilinear coordinate module, the solid heat transfer module, the coefficient form partial differential equation module, the Darcy's law module, and the solid mechanics module.
4. The method for multi-field coupled simulation modeling of composite material curing with different layup parameters based on COMSOL, as described in claim 1, is characterized in that... A multi-field coupled model of thermo-chemical-mechanical-fluid-solid interaction was constructed based on the COMSOL platform.