A prediction method for curing deformation of composite materials considering mold effect

Abstract

The present invention discloses a prediction method for composite material curing deformation considering the effect of molds. Considering the alternation of multiple material states and the coupling of multiple physical and chemical fields in the curing and molding process of composite materials, a curing deformation prediction model is developed based on ABAQUS user subroutine. The model includes two parts: a thermal-chemical model and a stress-strain model. The idea of ​​sequential thermal coupling is adopted to first calculate the distribution of the temperature field and the curing degree field on the composite material component, and then on this basis, the transformation of the mechanical properties of the composite material and the interaction between the mold and the component are considered to complete the prediction of curing deformation. The method based on sequential thermal coupling of the present invention accurately grasps the influencing factors such as the time-varying resin modulus and thermal performance parameters, the shrinkage of the resin and the thermal expansion of the composite material, the interaction between the mold and the component, and improves the accuracy of predicting the curing deformation of the composite material.

Description

Technical Field

[0001] The invention relates to the field of finite element simulation of composite material curing deformation, and in particular to a prediction method for composite material curing deformation taking into account the effect of a mold. Background Art

[0002] Composite materials have the characteristics of high specific modulus and specific strength, designability, good fatigue resistance and corrosion resistance, and are widely used in aerospace, transportation, shipbuilding, medical and other fields. Thermosetting resin-based composite materials are widely used in the aerospace field. The molding characteristics of thermosetting resin-based composite components are integral molding, which does not need to be manufactured into materials first and then made into components. This can greatly reduce the number of connectors, improve the reliability of composite structures, and reduce production costs. However, due to the external molding conditions of the components and the anisotropic layup of composite materials, the difference in thermal expansion coefficients of the components, the curing shrinkage of the resin, the interaction between the mold and the component, and the temperature gradient caused by the flow and thickness of the resin, the components will inevitably produce curing deformation after demolding due to the effect of thermal-chemical-force multi-field coupling. Excessive curing deformation will not only cause assembly difficulties, but also generate assembly stress that affects the performance of the product and even makes the product scrapped.

[0003] In order to reduce the deformation of composite products during the curing process, the geometry of the mold is usually repeatedly improved and compensated for based on experience and experiments. This method is very expensive and time-consuming. Therefore, the application of numerical calculation or finite element simulation methods to accurately predict the curing deformation of composite parts after molding at the beginning of the design has important guiding significance for the design and manufacture of molding molds. Summary of the invention

[0004] The purpose of the present invention is to propose a prediction method for the curing deformation of composite materials taking into account the effect of molds. This prediction method takes into account the alternation of various material states and the coupling of multiple physical and chemical fields during the curing and molding process of composite materials. Based on the ABAQUS user subroutine, a curing deformation prediction model is developed. The model includes two parts: a thermal-chemical model and a stress-strain model. The idea of ​​sequential thermal coupling is adopted to first calculate the distribution of the temperature field and the degree of curing field on the composite material component, and then on this basis, the transformation of the mechanical properties of the composite material and the interaction between the mold and the component are considered to complete the prediction of the curing deformation. The method based on sequential thermal coupling of the present invention accurately grasps the influencing factors such as the time-varying resin modulus and thermal performance parameters, the shrinkage of the resin and the thermal expansion of the composite material, the interaction between the mold and the component, and improves the accuracy of predicting the curing deformation of the composite material.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for predicting the curing deformation of a composite material taking into account the effect of a mold, comprising the following steps:

[0007] Step 1: In the 3D modeling software, establish a 3D model of the thermosetting resin-based composite material component, complete the grid division, and assign material properties and directions according to the 3D configuration.

[0008] Step 2: According to the actual curing process temperature curve, the thermal parameters of the thermosetting resin-based composite material are considered, and combined with the heat release of the resin in the thermosetting resin-based composite material during curing, the distribution of the real temperature field and curing degree field is obtained.

[0009] Step 3: According to the change of temperature and degree of curing over time obtained in step 2, the modulus of the thermosetting resin-based composite material is obtained, thereby obtaining the thermal expansion strain and curing shrinkage strain.

[0010] Step 4: Based on the distribution of temperature field and curing degree field, time-varying modulus of thermosetting resin-based composite materials, thermal expansion and curing shrinkage obtained in steps 2 and 3, displacement boundary conditions are applied and the curing deformation of thermosetting resin-based composite materials components is calculated using finite element software ABAQUS.

[0011] Preferably, the creation of the three-dimensional model in step 1 is completed in the "component" module of ABAQUS, and a shear layer is introduced to replace the interaction between the mold and the thermosetting resin-based composite material component. After the modeling of the thermosetting resin-based composite material component, the shear layer and the mold is completed, they are assembled according to the spatial position.

[0012] Preferably, the heat transfer in step 2 follows Fourier's heat transfer law, and combined with the law of conservation of energy, the heat transfer control equation is obtained as follows:

[0013]

[0014] Where T is temperature, t is time, ρ is the density of carbon fiber reinforced resin matrix composite material, λ x , y , z are the thermal conductivities of carbon fiber reinforced resin-based composite materials along the x, y, and z directions, respectively; C is the specific heat capacity of carbon fiber reinforced resin-based composite materials; the heat release model of the resin during the curing process is as follows:

[0015]

[0016] Where V f is the volume fraction of fiber, ρ r is the density of the resin, H R is the total heat released by unit mass of resin during the curing process, and dα / dt is the curing rate of the resin.

[0017] Preferably, the thermal parameters in step 2 include thermal conductivity, specific heat capacity and density, wherein the density is regarded as a constant. The thermal parameters of the carbon fiber reinforced resin matrix composite material are calculated by mixing ratio according to the thermal parameters of the resin and the fiber.

[0018] Preferably, the heat release of the resin in step 2 is characterized by a phenomenological model, specifically an autocatalytic model or an n-order reaction model in the phenomenological model, which are respectively:

[0019] dα / dt=K(T)α m (1-α) n (3)

[0020] dα / dt=K(T)(1-α) n (4)

[0021] Where α is the degree of curing, m and n are the reaction orders, and K(T) is the reaction rate function.

[0022]

[0023] Where A is the pre-factor; R s is the molar gas constant, AE is the activation energy, and the non-isothermal DSC method is used to fit A and R s , AE.

[0024] Preferably, the calculation of the temperature field and the degree of solidification field in step 2 is implemented with the aid of ABAQUS user subroutines DISP, USDFLD and HETVAL.

[0025] Preferably, in step 3, the thermal expansion coefficient of the carbon fiber reinforced resin-based composite material is as follows (6):

[0026]

[0027] α2=α3=(α 2f +ν 12f α 1f )V f +(α r +ν r α r )(1-V f )-[ν 12f V f +ν r (1-V f )]α1

[0028] In the formula, α r is the thermal expansion coefficient of the resin, α 1f is the thermal expansion coefficient of the fiber in the 1 direction, α 2fis the thermal expansion coefficient of the fiber in the 2-direction, E r is the elastic modulus of the resin, E 1f is the elastic modulus of the fiber in the 1 direction, v r is the Poisson's ratio of the resin, v 12f is the Poisson's ratio of the fiber. α1, α2, and α3 are the thermal expansion coefficients of the carbon fiber reinforced resin matrix composite material in the fiber 1 direction, fiber 2 direction, and fiber 3 direction.

[0029] The thermal expansion coefficient will change with the resin modulus, and the thermal expansion strain of the composite material can be obtained from the thermal expansion coefficient calculation formula of the composite material.

[0030] The curing shrinkage strain of carbon fiber reinforced resin-based composites is determined by the volume shrinkage rate of the resin during the curing process. The resin volume shrinkage rate model is as follows:

[0031]

[0032] In the formula, α d1 and α d2 They correspond to the degree of curing at the beginning and end of resin shrinkage, is the total volume shrinkage of the resin during the entire curing process, A sh is the factor of nonlinear curing degree. The volume shrinkage increment in each incremental step is obtained by formula (7), thereby obtaining the curing shrinkage strain of the resin.

[0033] Preferably, in step 3, the elastic modulus evolution of the resin is divided into three states during the curing process, namely, the rubber state, the state of rapid modulus establishment and the glass state, as shown below:

[0034]

[0035] In the formula,

[0036] T * =T g -T (9)

[0037] In the formula, and are the elastic modulus of the resin in rubber state and glass state, T c1 and T c2 Represents parameter T * The upper and lower critical values, T g is the glass transition temperature, T * Indicates the difference between the glass transition temperature and the current temperature. Poisson's ratio v of the resin during the curing process r Considered as a constant, the shear modulus is expressed as:

[0038]

[0039] The instantaneous linear elastic constitutive equation of curing and hardening is used to describe the changes in the mechanical properties of the resin during the curing process. The incremental form of the constitutive equation is:

[0040] Δσ i =C ij (α,T)Δε j (11)

[0041] In the formula, C ij (α,T) is the instantaneous stiffness coefficient, Δε j is the effective strain after deducting thermal expansion strain and curing shrinkage strain from the total strain, Δσ i is the effective strain Δε j The fiber properties do not change during curing. Combined with the instantaneous elastic modulus, shear modulus and Poisson's ratio of the resin during the curing process, the engineering constants of the carbon fiber reinforced resin-based composite material are predicted by a self-consistent method, thereby calculating the instantaneous stiffness matrix, adding the thermal expansion strain and curing shrinkage strain, thereby updating the total strain and stress of the carbon fiber reinforced resin-based composite material in each incremental step.

[0042] Preferably, in the displacement boundary condition applied in step 4, the normal displacement of the bottom surface of the mold is constrained before demolding, the mold and shear layer are removed by using Model change after demolding, and the radial displacement of the thermosetting resin-based composite material component is constrained, and finally the curing deformation of the thermosetting resin-based composite material component is predicted.

[0043] The positive and progressive effects of the present invention are:

[0044] The present invention takes into account the heat release of the resin and the transformation of material properties, can simulate the entire curing process of the composite material component in the mold, and reflects the distribution of multiple physical and chemical fields of heat, chemistry and force over time. It takes into account the influence of mold-component interaction, time-varying temperature, degree of cure, modulus, curing shrinkage stress and thermal stress on component deformation. Based on the idea of ​​sequential thermal-mechanical coupling, it accurately grasps the factors affecting curing deformation and improves the accuracy of predicting the curing deformation of composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A flow chart of a method for predicting the curing deformation of a composite material taking into account the effect of a mold provided by the present invention;

[0046] Figure 2 Schematic diagram of a typical L-shaped component structure used in an embodiment of the present invention;

[0047] Figure 3 Detailed dimension diagram of a typical L-shaped member used in an embodiment of the present invention;

[0048] Figure 4It is a finite element model of a typical L-shaped member, shear layer and mold assembly used in the embodiments of the present invention;

[0049] Figure 5 is a curing process curve diagram used in the embodiment of the present invention;

[0050] Figure 6 is a graph showing the degree of solidification change inside a typical L-shaped component used in an embodiment of the present invention;

[0051] Figure 7 A schematic diagram of the process of analyzing the temperature field, the curing degree field and the stress-strain of the present invention;

[0052] Figure 8 Schematic diagram of the prediction results of curing deformation of a typical L-shaped component used in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0054] The present invention provides a method for predicting the curing deformation of a composite material taking into account the effect of a mold, and the specific process is as follows: Figure 1 As shown, the following steps are included:

[0055] Step 1: Establish a three-dimensional finite element model of the thermosetting resin-based composite material component, the shear layer between the component and the mold, and the mold in the finite element software ABAQUS, and complete the assembly.

[0056] Step 2: Complete the division of the three-dimensional grids of components, shear layers and molds and the assignment of materials in the finite element software ABAQUS, and complete the assignment of component material directions.

[0057] Step 3: According to the actual curing process temperature curve, the thermal parameters of the thermosetting resin-based composite material are considered, and combined with the heat release of the resin in the thermosetting resin-based composite material during curing, the distribution of the real temperature field and curing degree field is obtained.

[0058] Step 4: According to the changes of temperature and curing degree over time obtained in step 3, the modulus of the thermosetting resin-based composite material is obtained, thereby obtaining the thermal expansion strain and curing shrinkage strain. Changes in temperature and curing degree will cause thermal expansion and curing shrinkage of the composite material, which is an important factor leading to curing deformation.

[0059] Step 5: Based on the temperature field and curing degree field distribution, time-varying modulus of thermosetting resin-based composite materials, thermal expansion and curing shrinkage obtained in steps 3 and 4, displacement boundary conditions are applied, and the curing deformation of thermosetting resin-based composite materials components can be calculated with the help of finite element software ABAQUS.

[0060] The present invention requires the secondary development function of the finite element software ABAQUS. HETVAL, USDFLD and DISP user subroutines are used in the calculation of temperature field and curing degree field; UMAT, USDFLD and UEXPAN subroutines are used in the calculation of thermal expansion strain and curing shrinkage strain and the change of the composite material modulus.

[0061] DISP: Defines the first type of boundary condition of the time-temperature function. Specifically, in the entire curing process, it defines the curing process temperature curve.

[0062] USDFLD: Define the temperature field and curing degree field variables at the material integration points.

[0063] HETVAL: Defines the heat generated inside the material.

[0064] UEXPAN: Defines the thermal expansion strain and curing shrinkage strain caused by changes in temperature and degree of curing at the material integration point.

[0065] UMAT: Defines the stress and material Jacobian matrices at the integration points in the current increment.

[0066] Example:

[0067] Select as Figure 2 The typical L-shaped component shown in the figure is the research object. The material is carbon fiber reinforced resin matrix composite material with a single layer thickness of 0.25 mm. Its basic structural dimensions are as follows Figure 3 As shown. The ply is laid in an orthogonal symmetric manner, with a ply ratio of [0 / 90] 3s , where 0° is the circumferential direction and 90° is the longitudinal direction.

[0068] right Figure 2 The specific process of predicting the curing deformation of the typical L-shaped component shown is as follows:

[0069] Step 1: Establish a 3D finite element model of the L-shaped component, shear layer and mold in the finite element software ABAQUS. In order to reduce the number of grids, speed up the calculation speed and make the calculation easier to converge, only the model from the center of the bend of the L-shaped component to a quarter of the total length is established. The shear layer is located between the mold and the L-shaped component, replacing the interaction between the mold and the component. Since the model structure is relatively simple, all modeling can be achieved by using the stretch command. After the L-shaped component, shear layer and mold are assembled, Figure 4 As shown, the thickness of the shear layer and the mold are 0.2 mm and 4 mm respectively. After assembly, binding constraints are applied between the L-shaped component and the shear layer, and between the shear layer and the mold.

[0070] Step 2: In the finite element software ABAQUS, assign material properties to the L-shaped component, shear layer and mold, and divide the three-dimensional grid. The L-shaped component is made of carbon fiber reinforced resin-based composite material. The thermal performance parameters of the resin and fiber are shown in Table 1. The mold material is aluminum. The parameters required for the shear layer are: thermal expansion coefficient 23.6×10 -6 ℃ -1 (length change caused by unit temperature change), elastic modulus 0.33Mpa and shear modulus 0.02Mpa, and the other parameters are consistent with the mold. The thickness of the L-shaped component is 2mm, and the ply method is [0 / 90] 3s Symmetrical plying, one unit is divided in each layer thickness; one unit is divided in the shear layer thickness; four units are divided in the mold thickness. This embodiment adopts a sequential thermal-mechanical coupling method, using the heat transfer unit DC3D8 when calculating the temperature and degree of solidification, and the static analysis unit C3D8 when analyzing the stress and deformation. Since the simulation involves heat transfer problems, when using the heat transfer unit in ABAQUS, the material direction assignment module that comes with the software cannot be used, and each layer of composite material can only be assigned direction separately.

[0071] Table 1 Thermal performance parameters of composite materials

[0072]

[0073] Step 3: According to the actual curing process temperature curve and the thermal parameters of the carbon fiber reinforced resin-based composite material, and combined with the heat released during the curing process of the resin in the carbon fiber reinforced resin-based composite material, the temperature field distribution of the composite material component is calculated. The heat transfer unit can simulate the transfer of heat. The transfer of heat follows the Fourier heat transfer law. Combined with the law of conservation of energy, the heat transfer control equation can be obtained as follows:

[0074]

[0075] Where T is temperature, t is time, ρ is the density of carbon fiber reinforced resin matrix composite material, λ x , y , z are the thermal conductivity of carbon fiber reinforced resin matrix composite materials along the x, y, and z directions, respectively, and C is the specific

[0076] Heat capacity. The left side of this equation is the energy required to heat up the microelement, and the first three items on the right side are the energy flowing into the microelement in the x, y, and z directions. The internal heat source refers to the heat released by the resin. In the present invention, the heat release model of the resin during the curing process is as follows:

[0077]

[0078] Where Vf is the volume fraction of fiber, ρ r is the density of the resin, H R is the total heat released by unit mass of resin during the curing process, and dα / dt is the curing rate of the resin. dα / dt involves the resin curing kinetic equation, which needs to be obtained by fitting the multivariate function through DSC experiments.

[0079] The heat transfer process requires thermal parameters, including thermal conductivity, specific heat capacity and density. Among them, the density changes little during the curing process and can be considered as a constant. The remaining thermal parameters are time-varying. According to the thermal parameters of resin and fiber, the thermal parameters of carbon fiber reinforced resin matrix composites can be obtained by using the mixed law.

[0080] The heat release of the resin is related to the resin curing kinetic model. The curing kinetic model describes the relationship between the resin curing rate, temperature and curing degree, and includes a mechanical model and a phenomenological model. Since the phenomenological model is relatively simple, it is usually selected to characterize the curing kinetics. Common phenomenological models include the autocatalytic model and the n-order reaction model, which are respectively expressed as equation (3) and equation (4):

[0081] dα / dt=K(T)α m (1-α) n (3)

[0082] dα / dt=K(T)(1-α) n (4)

[0083] Where α is the degree of curing, m and n are the reaction orders, and K(T) is the reaction rate function.

[0084]

[0085] Where A is the pre-factor; R s is the molar gas constant, AE is the activation energy, and the non-isothermal DSC method can be used to fit the required parameters. The autocatalytic model was selected, and the non-isothermal DSC method was used to obtain the starting temperature, peak temperature and end temperature of the exothermic peak of carbon fiber reinforced resin-based composite material curing at different heating rates. According to the Kissinger equation and the Crane equation, the required parameters can be fitted, where the reaction orders m and n are 0.5 and 1.5 respectively, and the pre-exponential factor A is 7.0×10 4 S -1 , the activation energy AE is 6.5×10 4 J / mol.

[0086] The entire curing process will go through the following curing process temperature curve: 20℃ as the initial temperature, heating at a rate of 2min / ℃ for 1 hour, then keeping warm for 1 hour, then heating at a rate of 2min / ℃ for 1 hour, then keeping warm for 2 hours, and finally cooling to room temperature at a rate of 2min / ℃. A constant pressure of 0.7Mpa is applied during the entire curing process. The curing process curve is as follows: Figure 5 As shown. In order to simulate the temperature environment in the autoclave more realistically, the mold surface and shear layer surface are set as forced temperature boundaries, the L-shaped component surface is set as a convection temperature boundary, and the symmetry surface is set as an insulation surface. The user-defined subroutines DISP, USDFLD, and HETVAL can calculate the distribution of the temperature and degree of cure inside the composite component. The change of degree of cure over time is shown in Figure 6 shown.

[0087] Step 4: Based on the temperature and curing degree of the composite material obtained in step 3, sequential thermal-mechanical coupling is used to take it as a predefined field to participate in the subsequent stress-deformation calculation. The difference between the thermal expansion coefficients of the resin and the fiber and the shrinkage of the resin during curing will cause non-mechanical strain. Since the composite material has orthogonal anisotropy, it has different thermal expansion coefficients in the longitudinal and transverse directions, and different thermal strains are generated under the same temperature load. The thermal expansion coefficient of the composite material is as follows (6):

[0088]

[0089] α2=α3=(α 2f +ν 12f α 1f )V f +(α r +ν r α r )(1-V f )-[ν 12f V f +ν r (1-V f )]α1

[0090] In the formula, α r is the thermal expansion coefficient of the resin, α 1f is the thermal expansion coefficient of the fiber in the 1 direction, α 2f is the thermal expansion coefficient of the fiber in the 2-direction, E r is the elastic modulus of the resin, E 1f is the elastic modulus of the fiber in the 1 direction, v r is the Poisson's ratio of the resin, ν 12f is the Poisson's ratio of the fiber. α1, α2, and α3 are the thermal expansion coefficients of the carbon fiber reinforced resin matrix composite material in the fiber 1 direction (x direction), fiber 2 direction (y direction), and fiber 3 direction (z direction).

[0091] The thermal expansion coefficient will change with the resin modulus, and the thermal expansion strain of the composite material can be obtained from the thermal expansion coefficient calculation formula of the composite material. The curing shrinkage strain of the composite material is mainly determined by the volume shrinkage rate of the resin during the curing process. The resin volume shrinkage rate model is as follows:

[0092]

[0093] In the formula, α d1 and α d2 They correspond to the degree of curing at the beginning and end of resin shrinkage, is the total volume shrinkage of the resin during the entire curing process, A sh is the factor of nonlinear curing degree. The above formula can be used to obtain the volume shrinkage increment in each incremental step, thereby obtaining the curing shrinkage strain of the resin. The resin is an isotropic material, and the shrinkage strain in each direction is equal. The resin volume shrinkage calculation formula is used to obtain the shrinkage strain increment in each incremental step. The curing shrinkage strain and thermal expansion strain need to be implemented with the help of the ABAQUS user subroutine UEXPAN.

[0094] Among them, the elastic modulus of the resin will change during the curing process. The instantaneous linear elastic constitutive model of curing and hardening is used to describe the changes in the mechanical properties of the resin during the curing process. It is characterized by the material properties being related to the glass transition temperature. The evolution of the elastic modulus of the resin can be divided into three stages during the curing process, namely, the viscous state, the state where the modulus is quickly established, and the fully cured state where no chemical reaction occurs, as shown below:

[0095]

[0096] In the formula,

[0097] T * =T g -T (9)

[0098] In the formula, and are the elastic modulus of the resin in rubber state and glass state, T c1 and T c2 Represents parameter T * The upper and lower critical values, T g is the glass transition temperature, T * Indicates the difference between the glass transition temperature and the current temperature. Poisson's ratio v of the resin during the curing process r It can be regarded as a constant, here we take v r =0.37, the shear modulus can be expressed as:

[0099]

[0100] Incremental form of the constitutive equation of carbon fiber reinforced resin matrix composites:

[0101] Δσ i =C ij (α,T)Δε j (11)

[0102] In the formula, C ij (α,T) is the instantaneous stiffness coefficient, Δε j is the effective strain after deducting thermal expansion strain and curing shrinkage strain from the total strain, Δσ i is the effective strain Δε j The fiber properties do not change during curing. The engineering constants of unidirectional carbon fiber reinforced resin-based composites can be predicted by a self-consistent method based on the instantaneous elastic modulus, shear modulus and Poisson's ratio of the resin during the curing process. The instantaneous stiffness matrix of the carbon fiber reinforced resin-based composites is calculated (the curing shrinkage strain is caused by the shrinkage of the resin, but is also applied to the entire composite material in the end). The total strain and stress of the carbon fiber reinforced resin-based composites in each incremental step Δt are updated by adding the thermal expansion strain and the curing shrinkage strain until t is greater than the maximum time t max This part needs to be implemented with the help of ABAQUS user subroutine UMAT. The update and transmission of key parameters in the user-defined subroutine during the entire composite material curing simulation process are as follows: Figure 7 shown.

[0103] Step 5: Apply displacement boundary conditions to one-quarter of the three-dimensional finite element model: Apply symmetric boundary conditions on the symmetric surface of the L-shaped component (center of the bend), constrain the normal displacement of the bottom surface of the mold before demolding, use Modelchange to remove the mold and shear layer after demolding, and constrain the radial displacement of a generatrix on the symmetric surface of the inner wall of the L-shaped component. Finally, use the finite element software ABAQUS to predict the strain, stress and curing deformation of the L-shaped component. Combined with steps 1-5, the actual curing deformation of the L-shaped composite component is predicted as follows: Figure 8 shown.

[0104] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for predicting the curing deformation of composite materials taking into account the effect of molds, characterized in that: The following steps are involved: Step 1: In the 3D modeling software, a 3D model of the thermosetting resin-based composite material component is established, and the grid is divided according to the 3D configuration, and the material properties and directions are assigned; Step 2: According to the actual curing process temperature curve, the thermal parameters of the thermosetting resin-based composite material are considered, and combined with the heat release of the resin in the thermosetting resin-based composite material during curing, the distribution of the real temperature field and curing degree field is obtained; Step 3: According to the change of temperature and curing degree with time obtained in step 2, the modulus of the thermosetting resin-based composite material is obtained, thereby obtaining the thermal expansion strain and the curing shrinkage strain; Step 4: Based on the distribution of temperature field and curing degree field, time-varying modulus of thermosetting resin-based composite materials, thermal expansion and curing shrinkage obtained in steps 2 and 3, displacement boundary conditions are applied, and the curing deformation of thermosetting resin-based composite materials components is calculated using finite element software ABAQUS; In step 3, the thermal expansion coefficient of the carbon fiber reinforced resin-based composite material is as follows (1): In the formula, α r is the thermal expansion coefficient of the resin, V f is the volume fraction of the fiber, α 1f is the thermal expansion coefficient of the fiber in the 1 direction, α 2f is the thermal expansion coefficient of the fiber in the 2-direction, E r is the elastic modulus of the resin, E 1f is the elastic modulus of the fiber in the 1 direction, v r is the Poisson's ratio of the resin, v 12f is the Poisson's ratio of the fiber; α1, α2, and α3 are the thermal expansion coefficients of the carbon fiber reinforced resin matrix composite material in the fiber 1 direction, the fiber 2 direction, and the fiber 3 direction; The thermal expansion strain of the composite material is obtained by the calculation formula of the thermal expansion coefficient of the composite material; The resin volume shrinkage model is as follows: Where α is the degree of curing, α d1 and α d2 They correspond to the degree of curing at the beginning and end of resin shrinkage, is the total volume shrinkage of the resin during the entire curing process, A sh is the factor of nonlinear curing degree; The volume shrinkage increment in each incremental step is obtained by formula (2), thereby obtaining the curing shrinkage strain of the resin; In step 3, the elastic modulus evolution of the resin is divided into three states during the curing process, namely, the rubber state, the state of rapid modulus establishment and the glass state, as shown below: In the formula, T * =T g -T (4) In the formula, and are the elastic modulus of the resin in rubber state and glass state respectively, T is the temperature, T c1 and T c2 Represents parameter T * The upper and lower critical values, T g is the glass transition temperature, T * Indicates the difference between the glass transition temperature and the current temperature; Poisson's ratio ν of the resin during the curing process r Considered as a constant, the shear modulus is expressed as: Where, ν r is the Poisson’s ratio of the resin; The instantaneous linear elastic constitutive equation of curing and hardening is used to describe the changes in the mechanical properties of the resin during the curing process. The incremental form of the constitutive equation is: Board i =C ij (a,T)No j (6) In the formula, C ij (α,T) is the instantaneous stiffness coefficient, Δε j is the effective strain after deducting thermal expansion strain and curing shrinkage strain from the total strain, Δσ i is the effective strain Δε j The corresponding stress; The fiber properties do not change during curing. Combined with the instantaneous elastic modulus, shear modulus and Poisson's ratio of the resin during the curing process, the engineering constants of the carbon fiber reinforced resin-based composite material are predicted by a self-consistent method, thereby calculating the instantaneous stiffness matrix, adding the thermal expansion strain and curing shrinkage strain, thereby updating the total strain and stress of the carbon fiber reinforced resin-based composite material in each incremental step.

2. A method for predicting the curing deformation of composite materials taking into account the effect of mold according to claim 1, characterized in that: The creation of the three-dimensional model in step 1 is completed in the "component" module of ABAQUS. The shear layer is introduced to replace the interaction between the mold and the thermosetting resin-based composite material component. After the modeling of the thermosetting resin-based composite material component, the shear layer and the mold is completed, they are assembled according to the spatial position.

3. A method for predicting the curing deformation of composite materials taking into account the effect of mold according to claim 1, characterized in that: The heat transfer in step 2 follows Fourier's heat transfer law. Combined with the law of conservation of energy, the heat transfer control equation is as follows: Where T is temperature, t is time, ρ is the density of carbon fiber reinforced resin matrix composite material, λ x , y , z are the thermal conductivities of the carbon fiber reinforced resin matrix composite materials along the x, y, and z directions, respectively, and C is the specific heat capacity of the carbon fiber reinforced resin matrix composite materials; The heat release model of the resin during the curing process is as follows: Where V f is the volume fraction of fiber, ρ r is the density of the resin, H R is the total heat released by unit mass of resin during the curing process, and dα / dt is the curing rate of the resin.

4. A method for predicting the curing deformation of composite materials taking into account the effect of mold according to claim 1, characterized in that: The thermal parameters in step 2 include thermal conductivity, specific heat capacity and density, wherein the density is regarded as a constant; the thermal parameters of the carbon fiber reinforced resin-based composite material are calculated using the mixing ratio according to the thermal parameters of the resin and the fiber.

5. The method for predicting the curing deformation of composite materials taking into account the effect of mold according to claim 1, characterized in that: The heat release of the resin in step 2 is characterized by a phenomenological model, specifically an autocatalytic model or an n-order reaction model in the phenomenological model, which are: dα / dt=K(T)α m (1-a) n (9) dα / dt=K(T)(1-α) n (10) Where α is the degree of curing, m and n are the reaction orders, and K(T) is the reaction rate function. Where A is the pre-factor; R s is the molar gas constant, AE is the activation energy, and the non-isothermal DSC method is used to fit A and R s , AE.

6. The method for predicting the curing deformation of composite materials taking into account the effect of mold according to claim 1, characterized in that: The calculation of the temperature field and the degree of solidification field in step 2 is achieved with the aid of ABAQUS user subroutines DISP, USDFLD and HETVAL.

7. The method for predicting the curing deformation of composite materials taking into account the effect of mold according to claim 1, characterized in that: In the step 4, in applying the displacement boundary condition, the normal displacement of the bottom surface of the mold is constrained before demolding, the mold and the shear layer are removed by using Modelchange after demolding, and the radial displacement of the thermosetting resin-based composite material component is constrained, and finally the curing deformation of the thermosetting resin-based composite material component is predicted.

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