Propellant anisotropic damage constitutive model construction method

Abstract

The invention relates to the technical field of materials, and discloses a propellant anisotropic damage constitutive model construction method and related equipment.The propellant anisotropic damage constitutive model construction method comprises the steps that based on the deformation gradient multiplicative decomposition theory, the total deformation gradient of a propellant is decomposed, and then a multi-scale damage evolution framework is established; respectively constructing a viscoelastic response model, a particle interface dissociation model, a dehumidification hole deformation model and a microcrack statistical evolution model in the multi-scale damage evolution framework, and coupling stress power contribution of each model to form a comprehensive damage constitutive equation; acquiring macro-mechanical response data and microstructure evolution data of the propellant, and performing inversion optimization on model parameters of the comprehensive damage constitutive equation in combination with an improved genetic algorithm; and based on the model parameters after inversion optimization, determining a constitutive model for quantitatively characterizing a coupling relationship between anisotropic damage, microstructure evolution and macromechanics response of the propellant. According to the invention, the prediction precision and applicability of the constitutive model under the load loading condition can be improved.

Description

Technical Field

[0001] The present application relates to the field of material technology, and in particular to a method for constructing an anisotropic damage constitutive model of a propellant and related equipment. Background Art

[0002] Composite solid propellants, as the core energy source of engines, have a performance directly related to their reliability and efficiency. However, in practical applications, propellants face complex operating conditions, including varying strain rates, temperature variations, and multiaxial stress states. These complex operating conditions lead to the generation of multiple microscopic damage mechanisms within the propellant, such as particle dewetting, microcrack propagation, and pore deformation. These damage mechanisms interact with each other, significantly affecting the propellant's macroscopic mechanical properties.

[0003] Currently, research on propellant damage constitutive models is primarily divided into two categories: macroscopic phenomenological models and micromechanical models. Macroscopic phenomenological models describe material softening through continuous damage variables, but most fail to fully characterize and describe the microscopic damage evolution mechanism. While micromechanical models attempt to model damage at the mesoscale, existing models still fail to fully account for microscopic damage mechanical behaviors such as particle dewetting and microcrack propagation, particularly in the characterization of anisotropic damage. Furthermore, existing models have limited applicability across different strain rates and stress states, making them difficult to adapt to the diverse and complex loading conditions that propellants may face in practical applications.

[0004] In summary, existing technologies have obvious shortcomings in fully integrating mesoscopic damage mechanisms, accurately characterizing anisotropic damage, and improving model prediction accuracy, which limits the effectiveness and reliability of propellant damage constitutive models in practical engineering applications. A new method is urgently needed to solve these technical difficulties.

[0005] The preceding description is intended to provide general background information and does not necessarily constitute prior art. Summary of the Invention

[0006] The embodiments of the present application provide a method for constructing an anisotropic damage constitutive model of a propellant and related equipment. By comprehensively integrating microscopic damage mechanisms such as viscoelastic response, particle interface dissociation, dewetting pore deformation, and statistical evolution of microcracks, quantitative characterization of the anisotropic damage, microscopic structural evolution, and macroscopic mechanical response of the propellant is achieved, thereby improving the prediction accuracy and applicability of the model under complex loading conditions.

[0007] In a first aspect, an embodiment of the present application provides a method for constructing an anisotropic damage constitutive model of a propellant, comprising:

[0008] Based on the theory of multiplicative decomposition of deformation gradient, the total deformation gradient of the propellant is decomposed into the product of the linear viscoelastic deformation gradient and the damage deformation gradient, and a multi-scale damage evolution framework is established.

[0009] Within the multi-scale damage evolution framework, a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model, and a microcrack statistical evolution model are constructed respectively, and the stress power contributions of each model are coupled to form a comprehensive damage constitutive equation;

[0010] The macroscopic mechanical response data and microscopic structural evolution data of the propellant are obtained through tensile tests at different strain rates, and the model parameters of the comprehensive damage constitutive equation are inversely optimized using an improved genetic algorithm.

[0011] Based on the model parameters after inversion optimization, a constitutive model is determined to quantitatively characterize the coupling relationship between propellant anisotropic damage, mesoscopic structural evolution and macroscopic mechanical response.

[0012] Optionally, in some embodiments of the present application, based on the theory of multiplicative decomposition of deformation gradient, the total deformation gradient of the propellant is decomposed into the product of the linear viscoelastic deformation gradient and the damage deformation gradient, and a multi-scale damage evolution framework is established, including:

[0013] defining an initial configuration, an intermediate configuration of hole damage, and an intermediate configuration of crack damage of the propellant, and decomposing a total deformation gradient into a product of a linear viscoelastic deformation gradient and a damage deformation gradient;

[0014] Further decomposing the damage deformation gradient into the product of the hole deformation gradient and the crack gradient;

[0015] Based on the decomposition results, a multi-scale damage evolution framework is established to integrate mesoscopic damage and macroscopic mechanical response.

[0016] Optionally, in some embodiments of the present application, the construction of the particle interface dissociation model includes:

[0017] The driving energy of particle-matrix interface dissociation is defined based on the stress work criterion to filter the effect of compressive stress on interface dissociation;

[0018] A dynamically decaying energy transfer coefficient is introduced, which decays exponentially with increasing interface dissociation length, to characterize the inhibitory effect of the interface dissociation degree on energy transfer.

[0019] Optionally, in some embodiments of the present application, the construction of the microcrack statistical evolution model includes:

[0020] Based on the statistical crack mechanics theory, it is assumed that the microcrack size obeys an exponential distribution, and the normal direction of the microcrack is discretized into a finite number of discrete directions;

[0021] The power-law relationship between microcrack growth rate and energy release rate is defined, and the microcrack size and direction distribution are dynamically updated by combining the crack surface friction coefficient and critical energy release rate.

[0022] Optionally, in some embodiments of the present application, the inverse optimization of the model parameters of the comprehensive damage constitutive equation using an improved genetic algorithm includes:

[0023] The fitness function is designed as the weighted square sum of experimental stress data and model prediction values, and a non-uniform mutation strategy is introduced to adjust the range of chromosome variation.

[0024] Through the joint inversion of tensile test data under multiple strain rates, the viscoelastic parameters, interface dissociation parameters, pore evolution parameters and microcrack parameters are simultaneously optimized to obtain the corresponding global optimal solution.

[0025] Optionally, in some embodiments of the present application, determining a constitutive model for quantitatively characterizing the coupling relationship between anisotropic damage, microstructure evolution, and macroscopic mechanical response of the propellant based on the inverse optimized model parameters includes:

[0026] Substituting the inverse-optimized model parameters into the comprehensive damage constitutive equation, coupling the viscoelastic stress, pore softening stress and microcrack anisotropic stress components;

[0027] Based on the dynamic update mechanism of mesoscopic damage parameters, the quantitative relationship between macroscopic stress-strain response, particle dewetting degree and microcrack propagation path is output in real time.

[0028] Optionally, in some embodiments of the present application, the method further includes:

[0029] measuring full-field strain data of the propellant in real time, wherein the full-field strain data includes longitudinal strain data and lateral strain data;

[0030] The prediction accuracy of the constitutive model for Poisson's ratio strain correlation and strain rate sensitivity is verified based on the full-field strain data.

[0031] In a second aspect, an embodiment of the present application provides a device for constructing an anisotropic damage constitutive model of a propellant, comprising:

[0032] The framework module is used to decompose the total deformation gradient of the propellant into the product of the linear viscoelastic deformation gradient and the damage deformation gradient based on the multiplicative decomposition theory of deformation gradient, and establish a multi-scale damage evolution framework;

[0033] A coupling module is used to construct a viscoelastic response model, a particle interface dissociation model, a dewetting hole deformation model, and a microcrack statistical evolution model within the multi-scale damage evolution framework, and couple the stress power contribution of each model to form a comprehensive damage constitutive equation;

[0034] An optimization module is used to obtain macroscopic mechanical response data and microscopic structural evolution data of the propellant through tensile tests at different strain rates, and to perform inverse optimization of the model parameters of the comprehensive damage constitutive equation using an improved genetic algorithm;

[0035] A building module is used to determine the constitutive model for quantitatively characterizing the coupling relationship between propellant anisotropic damage, mesostructure evolution and macromechanical response based on the model parameters after inversion optimization.

[0036] In a third aspect, an embodiment of the present application further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for constructing an anisotropic damage constitutive model of a propellant as described in the first aspect are implemented.

[0037] In a fourth aspect, an embodiment of the present application further provides a readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the computer program implements the method for constructing an anisotropic damage constitutive model of a propellant as described in the first aspect.

[0038] The present application provides a method for constructing an anisotropic damage constitutive model of a propellant and related equipment. First, through a multi-scale damage evolution framework based on the multiplicative decomposition theory of deformation gradients, the total deformation gradient is decomposed into the product of the linear viscoelastic deformation gradient and the damage deformation gradient, thereby achieving deep coupling between the microscopic damage mechanism and the macroscopic mechanical response. Then, by separately constructing a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model, and a microcrack statistical evolution model, and coupling the stress-power contribution of each model, a comprehensive damage constitutive equation is formed, which comprehensively integrates multiple microscopic damage mechanisms. Next, combining tensile test data at different strain rates with an improved genetic algorithm, the model parameters are inversely optimized to ensure the accuracy and reliability of the model parameters. Finally, based on the inverse-optimized model parameters, a constitutive model is output that can comprehensively characterize the coupling relationship between the anisotropic damage of the propellant, the microscopic structural evolution, and the macroscopic mechanical response. It can be seen that this application can achieve quantitative characterization of propellant anisotropic damage, microstructural evolution and macroscopic mechanical response, improve the applicability and reliability of the propellant damage constitutive model under complex loading conditions, and provide reliable theoretical support for the engineering application of propellant mechanical behavior. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 This is an application environment diagram of the method for constructing an anisotropic damage constitutive model of a propellant provided in an embodiment of the present application;

[0041] Figure 2 1 is a flow chart of a method for constructing an anisotropic damage constitutive model of a propellant provided in an embodiment of the present application;

[0042] Figure 3 This is a schematic diagram of the structure of the damage model components provided in the embodiment of the present application;

[0043] Figure 4 Schematic diagram of the initial configuration, damaged configuration, and current configuration of a propellant during large deformation caused by damage provided by an embodiment of the present application;

[0044] Figure 5 Schematic diagram of the process of calculating constitutive parameters provided in the embodiment of the present application;

[0045] Figure 6 Schematic diagram of the structure of the anisotropic damage constitutive model construction device for propellant provided in an embodiment of the present application;

[0046] Figure 7 1 is another structural schematic diagram of the apparatus for constructing an anisotropic damage constitutive model of a propellant provided in an embodiment of the present application;

[0047] Figure 8 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of systems and methods consistent with aspects of the present application, as detailed in the appended claims.

[0049] It should be noted that, in this document, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive descriptions such as inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context of the specific embodiment.

[0050] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0051] In the subsequent description, the use of suffixes such as "module", "component" or "unit" to represent elements is only for the purpose of facilitating the description of the present application and has no specific meaning. Therefore, "module", "component" or "unit" can be used interchangeably.

[0052] In order to solve the above-mentioned technical problems and overcome the defects of the existing technology, the embodiments of the present application provide a method for constructing an anisotropic damage constitutive model of propellant and related equipment. By comprehensively integrating microscopic damage mechanisms such as viscoelastic response, particle interface dissociation, dewetting pore deformation and statistical evolution of microcracks, quantitative characterization of the anisotropic damage, microscopic structural evolution and macroscopic mechanical response of the propellant is achieved, thereby improving the prediction accuracy and applicability of the model under complex loading conditions.

[0053] Figure 1 This is an application environment diagram of a method for constructing anisotropic damage constitutive model of propellant in an embodiment. Figure 1The method for constructing an anisotropic damage constitutive model for a propellant is applied to a system for constructing an anisotropic damage constitutive model for a propellant. The system includes a terminal 110 and a server 120. Terminal 110 and server 120 are connected via a network. Terminal 110 can be a desktop terminal or a mobile terminal. The mobile terminal can be at least one of a mobile phone, a tablet computer, and a laptop computer. Server 120 can be implemented as a standalone server or a server cluster consisting of multiple servers. Terminal 110 is used to decompose the total deformation gradient of the propellant into the product of the linear viscoelastic deformation gradient and the damage deformation gradient based on the multiplicative decomposition theory of deformation gradient, and establish a multi-scale damage evolution framework; within the multi-scale damage evolution framework, a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model and a microcrack statistical evolution model are constructed respectively, and the stress power contribution of each model is coupled to form a comprehensive damage constitutive equation; the macroscopic mechanical response data and microscopic structural evolution data of the propellant are obtained through tensile tests at different strain rates, and the model parameters of the comprehensive damage constitutive equation are inversely optimized by combining an improved genetic algorithm; based on the inverse-optimized model parameters, a constitutive model is determined for quantitatively characterizing the coupling relationship between the anisotropic damage, microscopic structural evolution and macroscopic mechanical response of the propellant.

[0054] See also Figure 2 , Figure 2 : This is a flow chart of a method for constructing an anisotropic damage constitutive model of a propellant provided in one embodiment of the present application. This embodiment mainly uses the application of the method for constructing an anisotropic damage constitutive model of a propellant to a computer device as an example to illustrate. The method for constructing an anisotropic damage constitutive model of a propellant provided in one embodiment of the present application may specifically include the following steps:

[0055] S1. Based on the theory of multiplicative decomposition of deformation gradients, the total deformation gradient of the propellant is decomposed into the product of the linear viscoelastic deformation gradient and the damage deformation gradient, and a multi-scale damage evolution framework is established;

[0056] Specifically, for step S1, because the propellant exhibits significant mesoscopic damage mechanisms (such as particle dewetting and microcrack propagation) under complex loading conditions, traditional models have difficulty simultaneously describing the coupled relationship between mesoscopic damage and macroscopic mechanical response. This step uses the multiplicative decomposition theory of deformation gradients to decompose the total deformation gradient into a linear viscoelastic deformation gradient (reflecting the elastic and viscoelastic behavior of the material) and a damage deformation gradient (reflecting the mesoscopic damage mechanism); the damage deformation gradient is further decomposed into a pore deformation gradient (characterizing particle dewetting) and a crack deformation gradient (characterizing microcrack propagation). By separating and coupling the mesoscopic damage mechanism with the macroscopic mechanical behavior, the model can more accurately describe the mechanical behavior of the propellant under complex loading conditions, addressing the limitations of traditional models in describing the evolution of mesoscopic damage.

[0057] S2. Within the multiscale damage evolution framework, a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model, and a microcrack statistical evolution model are constructed. The stress-power contributions of each model are coupled to form a comprehensive damage constitutive equation.

[0058] Specifically, existing models usually only consider a single damage mechanism (such as holes or cracks) and cannot fully describe the complex damage behavior of propellants. To solve this problem, this step constructs a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model, and a microcrack statistical evolution model within the multi-scale damage evolution framework, and couples the stress-power contribution of each model to form a comprehensive damage constitutive equation. The viscoelastic response model uses a generalized Maxwell model to describe the viscoelastic behavior of the propellant, and expresses the relaxation modulus in the form of a Prony series, which can accurately capture the relaxation behavior of the material. The particle interface dissociation model defines the driving energy for particle-matrix interface dissociation based on the stress work criterion, and introduces a dynamically attenuated energy transfer coefficient to characterize the inhibitory effect of the degree of interface dissociation on energy transfer. The dewetting pore deformation model uses a viscoelastic constitutive relation in the form of genetic integration to describe the time-varying characteristics of the pore volume, taking into account the volume expansion effect and softening effect of the pore. The microcrack statistical evolution model is based on the statistical crack mechanics theory, assuming that the microcrack size obeys an exponential distribution, and discretizing the normal direction of the microcrack into a finite number of discrete directions, defining a power-law relationship between the microcrack propagation rate and the energy release rate. Finally, by linearly superimposing the stress-power contributions of each model, a comprehensive damage constitutive equation was formed, which fully integrated a variety of mesoscopic damage mechanisms, including particle dewetting, pore expansion, and microcrack propagation, thereby more accurately reflecting the mechanical behavior of the propellant under complex loading conditions and solving the shortcomings of existing models in describing multiple damage mechanisms.

[0059] S3. Obtain macroscopic mechanical response data and microscopic structural evolution data of the propellant through tensile tests at different strain rates. Inversely optimize the model parameters of the comprehensive damage constitutive equation using an improved genetic algorithm.

[0060] Specifically, traditional parameter identification methods (such as the simplex method or the least squares method) are prone to fall into local optimal solutions when dealing with complex constitutive models, resulting in insufficient model prediction accuracy. For step S2, tensile tests at different strain rates (such as 0.001-1.0s -1) to obtain the macroscopic mechanical response data (such as stress-strain curves) and microscopic structural evolution data (such as the degree of particle dehumidification and the path of microcrack propagation) of the propellant. The genetic algorithm is improved collectively, and a non-uniform mutation strategy is introduced to adjust the range of chromosome variation. The fitness function is designed to be the weighted square sum of the experimental stress data and the model prediction value. Through the joint inversion of experimental data under multiple strain rates, the viscoelastic parameters, interface dissociation parameters, pore evolution parameters and microcrack parameters are simultaneously optimized. The improved genetic algorithm can effectively improve the global search capability and convergence speed of parameter identification, ensuring the accuracy and reliability of the model parameters. Through the combination of experimental data and optimization algorithm, the identification process of model parameters is more efficient and accurate, thereby significantly improving the prediction ability of the model.

[0061] S4. Based on the inverse-optimized model parameters, determine the constitutive model for quantitatively characterizing the coupling relationship between anisotropic propellant damage, microstructural evolution, and macroscopic mechanical response;

[0062] Specifically, existing models have large errors in predicting the macroscopic mechanical response (such as stress-strain curves and Poisson's ratio changes) and microscopic structural evolution (such as the degree of particle dewetting and microcrack propagation paths) of propellants. For step S4, the model parameters after inversion optimization are substituted into the comprehensive damage constitutive equation, coupling the viscoelastic stress, pore softening stress, and microcrack anisotropic stress components. Through the dynamic update mechanism of the microscopic damage parameters, the quantitative relationship between the macroscopic stress-strain response, the degree of particle dewetting, and the microcrack propagation path is output in real time. In addition, through experimental verification (such as tensile tests at different strain rates), the model can accurately predict the macroscopic mechanical response and microscopic structural evolution of the propellant, improving the applicability and reliability of the propellant damage constitutive model under complex loading conditions.

[0063] It can be seen that this embodiment achieves a comprehensive quantitative characterization of the anisotropic damage, microstructural evolution, and macroscopic mechanical response of the propellant through an innovative theoretical framework (theory of multiplicative decomposition of deformation gradients), the construction of a comprehensive damage model, and an improved parameter optimization algorithm. This not only solves the problem of insufficient prediction accuracy of existing models under complex loading conditions, but also provides reliable theoretical support for the engineering application of propellant mechanical behavior.

[0064] Optionally, in some embodiments, step S1 "based on the theory of multiplicative decomposition of deformation gradients, decomposing the total deformation gradient of the propellant into the product of the linear viscoelastic deformation gradient and the damage deformation gradient, and establishing a multi-scale damage evolution framework" may specifically include:

[0065] S11. Define the initial configuration, intermediate configuration of hole damage, and intermediate configuration of crack damage of the propellant, and decompose the total deformation gradient into the product of the linear viscoelastic deformation gradient and the damage deformation gradient;

[0066] Specifically, the initial configuration, intermediate configuration of pore damage, and intermediate configuration of crack damage of the propellant are defined. The initial configuration refers to the geometric state of the propellant when it is unloaded and serves as a reference configuration. The intermediate configuration of pore damage refers to the pore damage state caused by particle dewetting, characterizing the local deformation after the particle-matrix interface dissociates. The intermediate configuration of crack damage refers to the crack damage state caused by microcrack propagation, characterizing the impact of crack propagation on the overall deformation of the material. By defining intermediate configurations, the microscopic damage mechanism is decoupled from the macroscopic mechanical response, facilitating separate modeling and subsequent coupling. The total deformation gradient is decomposed into the product of the linear viscoelastic deformation gradient and the damage deformation gradient. The linear viscoelastic deformation gradient characterizes the elastic and viscous responses of the material.

[0067] S12. Further decompose the damage deformation gradient into the product of the hole deformation gradient and the crack gradient;

[0068] Specifically, the damage deformation gradient is further decomposed into the pore deformation gradient and the crack deformation gradient. The pore deformation gradient characterizes the pore volume expansion caused by particle dewetting; the crack deformation gradient characterizes the anisotropic damage caused by microcrack extension; by providing a quantitative relationship between microscopic damage and macroscopic mechanical behavior, the physical interpretability of the model is enhanced.

[0069] S13. Based on the decomposition results, a multi-scale damage evolution framework is established to integrate microscopic damage and macroscopic mechanical response.

[0070] Specifically, the multi-scale damage evolution framework can be implemented through the following steps: micro-damage modeling, constructing the evolution equations of hole damage and crack damage respectively; coupling the micro-damage contribution with the macro-mechanical response through the stress-power superposition principle; using the finite element method or explicit dynamics algorithm to achieve numerical solution of the framework; achieving deep coupling of the micro-damage mechanism and the macro-mechanical response, thereby improving the prediction accuracy of the model.

[0071] Optionally, in some embodiments, the construction of the particle interface dissociation model in step S2 may specifically include:

[0072] The driving energy of particle-matrix interface dissociation is defined based on the stress work criterion to filter the effect of compressive stress on interface dissociation;

[0073] A dynamically decaying energy transfer coefficient is introduced, and the energy transfer coefficient decays exponentially with the increase of the interface dissociation length to characterize the inhibitory effect of the interface dissociation degree on energy transfer.

[0074] Specifically, to construct the particle interface dissociation model, the driving energy for particle-matrix interface dissociation is first defined by calculating the energy increment of the work done by the interface stress. Then, by introducing a load condition, the effect of compressive stress on interface dissociation is filtered out, and only the effect of tensile stress is considered. Finally, a dynamically decaying energy transfer coefficient is introduced. As the interface dissociation length increases, the energy transfer coefficient decays exponentially, characterizing the inhibitory effect of the degree of interface dissociation on energy transfer. This embodiment defines the driving energy through the stress work criterion and introduces a dynamically decaying energy transfer coefficient. This not only accurately identifies the driving energy for interface dissociation, but also dynamically characterizes the inhibitory effect of the degree of interface dissociation on energy transfer, providing important theoretical support for the construction of propellant damage constitutive models.

[0075] Optionally, in some embodiments, the construction of the microcrack statistical evolution model in step S2 may specifically include:

[0076] Based on the statistical crack mechanics theory, it is assumed that the microcrack size obeys an exponential distribution, and the normal direction of the microcrack is discretized into a finite number of discrete directions;

[0077] The power-law relationship between microcrack growth rate and energy release rate is defined, and the microcrack size and direction distribution are dynamically updated by combining the crack surface friction coefficient and critical energy release rate.

[0078] Specifically, for the construction of the statistical evolution model of microcracks, based on the statistical crack mechanics theory, it is assumed that the size of microcracks inside the propellant obeys an exponential distribution, and the normal direction of the microcracks is discretized into a finite number of directions to simplify the calculation and improve numerical stability. For example, the hemisphere is divided into 31 discrete directions; the power-law relationship between the microcrack propagation rate and the energy release rate is defined, which can accurately describe the dynamic behavior of crack propagation and improve the prediction accuracy of the model; the crack surface friction coefficient is introduced to consider the friction effect during crack closure, which can more realistically reflect the mechanical behavior during the crack closure process and enhance the physical authenticity of the model; at the same time, during the loading process, the size and direction distribution of the microcracks are dynamically updated according to the current stress state and energy release rate, reflecting the evolution process of the microcracks in real time, providing support for the real-time prediction of the model.

[0079] Optionally, in some embodiments, the inverse optimization of the model parameters of the comprehensive damage constitutive equation in combination with the improved genetic algorithm in step S3 may specifically include:

[0080] S31. Design a fitness function as the weighted square sum of experimental stress data and model predictions, and introduce a non-uniform mutation strategy to adjust the range of chromosome variation.

[0081] Specifically, for the inverse optimization process of model parameters, the fitness function is first defined as the weighted sum of squares between the experimental stress data and the model prediction value, and a non-uniform mutation strategy is introduced to adjust the range of chromosome variation. The variation length decreases with the increase of the iterative generation number to ensure the precision of the later search; by designing a reasonable fitness function, the advantages and disadvantages of the model parameters can be effectively evaluated and the accuracy of parameter optimization can be improved; the non-uniform mutation strategy can avoid the premature convergence problem of traditional genetic algorithms, improve the global search capability, and ensure the acquisition of the global optimal solution.

[0082] S32. Through the joint inversion of tensile test data at multiple strain rates, the viscoelastic parameters, interface dissociation parameters, pore evolution parameters, and microcrack parameters are simultaneously optimized to obtain the corresponding global optimal solution.

[0083] Specifically, at different strain rates (such as 0.001, 0.01, 0.05, 0.15, 0.5, 1.0s -1 ) to obtain macroscopic mechanical response data for the propellant. The experimental data at multiple strain rates were combined to construct a comprehensive objective function, which simultaneously optimized the model's viscoelastic parameters, interfacial dissociation parameters, pore evolution parameters, and microcrack parameters. Finally, an improved genetic algorithm was used to ensure a global optimal solution within the complex parameter space.

[0084] This embodiment, through the joint inversion of multi-strain rate experimental data, can comprehensively cover the mechanical behavior of the propellant under different loading conditions, thereby improving the applicability and predictive ability of the model; the simultaneous optimization of multiple parameters can ensure the coordination between the model parameters and avoid model distortion caused by the optimization of a single parameter; the improved genetic algorithm can effectively improve the efficiency and accuracy of parameter optimization and ensure the global optimality of the model parameters.

[0085] Optionally, in some embodiments, step S4 of “determining a constitutive model for quantitatively characterizing the coupling relationship between anisotropic damage, microstructure evolution, and macroscopic mechanical response of the propellant based on the inverse optimized model parameters” may specifically include:

[0086] S41. Substitute the inverse optimized model parameters into the comprehensive damage constitutive equation, coupling the viscoelastic stress, pore softening stress and microcrack anisotropic stress components;

[0087] Specifically, the model parameters obtained by optimizing the improved genetic algorithm include viscoelastic parameters, interface dissociation parameters, pore evolution parameters and microcrack parameters; the viscoelastic stress, pore softening stress and microcrack anisotropic stress components are coupled into the comprehensive damage constitutive equation. In addition, other microscopic damage mechanisms (such as matrix tearing and interface bonding) can be introduced to further enrich the physical background of the model. Under the condition of thermal-mechanical coupling, the influence of temperature on the viscoelastic, pore and crack stress components is introduced. This embodiment ensures the accuracy and coordination of the model parameters and improves the prediction accuracy of the model by substituting the optimized parameters into the comprehensive damage constitutive equation; coupling multiple stress components can fully reflect the complex mechanical behavior of the propellant and enhance the physical authenticity and applicability of the model.

[0088] S42. Based on the dynamic update mechanism of mesoscopic damage parameters, the quantitative relationship between macroscopic stress-strain response, particle dewetting degree, and microcrack propagation path is output in real time;

[0089] Specifically, during the loading process, the microscopic damage parameters (such as the void volume fraction, crack density, crack propagation rate, etc.) are updated in real time, which can reflect the damage evolution process in real time and improve the dynamic response capability of the model. By numerically solving the comprehensive damage constitutive equation, the quantitative relationship between the macroscopic stress-strain response, the degree of particle dewetting and the microcrack propagation path is output in real time, thereby providing a direct prediction tool for engineering applications, so that the subsequent design and use of propellants can be effectively guided.

[0090] Optionally, in some embodiments, the method may further include:

[0091] S51. Real-time measurement of full-field strain data of the propellant, including longitudinal strain data and lateral strain data;

[0092] Specifically, digital image correlation (DIC) technology is used for non-contact full-field strain measurement. DIC technology uses a high-speed camera to capture the deformation process of the sample surface and calculates the strain distribution using image processing algorithms. For example, a high-speed camera with a resolution of 2048×2048 pixels and a frame rate of 1000fps is used to capture the deformation process. A rectangular area of ​​10mm (width) × 30mm (length) is selected in the middle area of ​​the sample as the analysis area. By drawing longitudinal and transverse center reference lines and setting equidistant line segments, the logarithmic strain is calculated. By measuring the full-field strain data in real time, the deformation behavior of the propellant during the loading process can be fully captured, providing rich experimental data support. The non-contact measurement method avoids the interference of traditional strain gauges on the deformation of the sample and improves the accuracy and reliability of the measurement.

[0093] S52. Verify the prediction accuracy of the constitutive model for Poisson's ratio strain correlation and strain rate sensitivity based on full-field strain data;

[0094] Specifically, the instantaneous Poisson's ratio of the propellant is calculated based on full-field strain data. The model's accuracy in predicting the Poisson's ratio-strain correlation and strain rate sensitivity is verified by comparing the Poisson's ratio curves at different strain rates. The verification process includes: conducting tensile tests at different strain rates to obtain full-field strain data; substituting the optimized model parameters into the constitutive model to predict how the Poisson's ratio changes with strain and strain rate; comparing the experimental data with the model's predicted results, and calculating the relative deviation between the experimental and model-predicted Poisson's ratios. Additionally, other verification metrics, such as stress-strain curves and volume expansion curves, can be introduced to comprehensively evaluate the model's predictive capabilities.

[0095] This embodiment is verified by full-field strain data and can accurately evaluate the prediction accuracy of the model for Poisson's ratio strain correlation and strain rate sensitivity, ensuring the reliability and applicability of the model.

[0096] To facilitate understanding of the method for constructing an anisotropic damage constitutive model of a propellant provided in this application, this embodiment also provides a specific implementation method for constructing an anisotropic damage constitutive model of a propellant, including the following steps:

[0097] First, a dynamic analysis of the constitutive model is performed. This example uses the following vector and tensor operations:

[0098]

[0099] I Dev =II Vol ;

[0100] Au≡A ik u k e i ;

[0101] u·v≡u k v k ;A:B≡tr(A T B)A ik B ik ;

[0102] A:B≡tr(A T B)=A ik B ik ;

[0103] where δ ij is the Kronecker symbol; i is the second-order unit tensor; I is the fourth-order unit tensor; I Volis the volume unit tensor; I Dev is the Deviatric unit tensor, {e i}(i=1,2,3) are arbitrary basis vectors, u and v are vectors, A and B are symmetric second-order tensors, and C is a fourth-order tensor.

[0104] See also Figure 3 The schematic diagram of a one-dimensional model of the propellant anisotropic damage constitutive model based on the microscopic dewetting and microcrack evolution mechanism proposed in this embodiment is shown in FIG. Figure 3 As shown in Figure 1, the model consists of a series of viscoelastic, pore, and microcrack elements. The viscoelastic element reflects the viscoelastic effects of the composite solid propellant, the pore element primarily describes the volume expansion and softening effects caused by dewetting of the AP particles, and the microcrack element describes the evolution and propagation of distributed microcracks within the propellant. The model involves four physical mechanisms: the generalized Maxwell viscoelastic model in Part 1, the interfacial dissociation and dewetting model in Part 2, the pore deformation model in Part 3, and the microcrack model in Part 4.

[0105] Based on the deformation gradient elastic-plastic multiplication decomposition theory, this embodiment proposes two hypothetical intermediate configurations (such as Figure 4 (shown): One is the hole damage intermediate structure Ω caused by particle dewetting v , the second is the crack damage intermediate structure Ω formed by the expansion of microcracks c These two configurations together constitute the damage configuration of the composite solid propellant during deformation, providing a theoretical framework for describing the damage evolution of composite solid propellants.

[0106] As shown in Equation (4.1), the total deformation gradient F is decomposed into the linear viscoelastic deformation gradient F vis and damage deformation gradient F d Furthermore, as shown in Equation (4.2), the damage deformation gradient F d It can be decomposed into the hole deformation gradient F v and crack deformation gradient F c The product form of:

[0107] F=F vis F d (4.1)

[0108] F d =F c F v (4.2)

[0109] According to the extreme decomposition of deformation gradient, equations (4.1) and (4.2) can be written as equations (4.3) and (4.4), where V vis With V c is the left stretch tensor, U d with Uv is the right stretch tensor, R vis 、R d 、R c and R v is the rotation tensor.

[0110] F=V vis R vis R d U d (4.3)

[0111] F d =V c R c R v U v (4.4)

[0112] According to the calculation formula of the total velocity gradient L and the decomposition formula of the deformation gradient (4.1), we can obtain:

[0113]

[0114] Similarly, the damage deformation velocity gradient L d The calculation formula is as follows:

[0115]

[0116] In formula (4.6), L c is the microcrack velocity gradient tensor of the intermediate configuration. vis L d (F vis ) -1 Record According to equations (4.5) and (4.6), we can get The calculation formula can be written as:

[0117]

[0118] Starting from the calculation formula of the stress power per unit reference configuration volume, the conjugate stress and strain metrics can be derived:

[0119]

[0120] Where τ represents the symmetrical Kirchhoff stress tensor, and W& represents the stress power or the rate of change of internal energy per unit reference configuration volume. The stress power on the right side of equation (4.8) can be decomposed into three independent parts: the viscoelastic part Microcrack part and hole part These correspond to the three main deformation mechanisms of the material. This decomposition method is based on the following considerations: the total stress power is equal to the linear superposition of the stress power of each deformation mechanism; each deformation mechanism is independent of each other and its contribution to the mechanical response of the material can be described separately by the corresponding constitutive relations. Based on the above decomposition, the following three power expressions can be obtained:

[0121]

[0122] In formula (4.10) is the velocity gradient tensor in the current configuration caused by microcracks. vis F c ) T τ(F vis F c ) -T Denoted as:

[0123] (F vis F c ) T τ(F vis F c ) -T =M v (4.12)

[0124] M v is the Mandel stress conjugate to the velocity gradient in the pore part, which is an asymmetric tensor in the intermediate configuration.

[0125] In equations (4.3) and (4.4), R vis R d and R c R v They represent the initial configuration Ω 0 The total rotation tensor to the current configuration Ω and the total rotation tensor from the initial configuration Ω 0 To the intermediate damage configuration Ω c The total rotation tensor of . Studies have shown that the rotation combination R vis and R d 、R c and R v The specific numerical distribution of has negligible influence on the final calculation results. In order to facilitate the numerical realization of the large deformation damage constitutive model, this study adopts the following assumptions: Let R v =I, that is, the rotational deformation during the large deformation process of the propellant is attributed to viscoelastic deformation and microcrack deformation. This assumption is mainly based on the following two considerations:

[0126] 1. Particle dewetting mainly leads to separation of the particle-matrix interface, and the resulting rotation effect is relatively weak;

[0127] 2. Viscoelastic deformation and microcrack extension deformation are the main mechanisms for generating rotation effect in composite solid propellants.

[0128] The above assumptions take into account the characteristics of pores and microcracks in composite solid propellants. They not only maintain the microscopic background mechanism of the model, but also improve the simplicity and stability of numerical calculations, providing convenience for subsequent finite element implementation. At this point, equations (4.1) and (4.2) can be rewritten as follows:

[0129] F=V vis R vis R c U c U v (4.13)

[0130] F d =R c U c U v (4.14)

[0131] Among them, the generalized Maxwell viscoelastic model is used to characterize the viscoelastic mechanical behavior of composite solid propellants. Its constitutive relationship is described in the integral form of linear viscoelastic theory:

[0132]

[0133] Where, E vis The Hencky strain tensor representing the deformation of the viscoelastic element is defined as E vis =ln(V vis ). G(t) is the fourth-order tensor of the viscoelastic relaxation modulus, expressed in the form of Prony series:

[0134]

[0135] Among them, G ∞ is the steady-state relaxation modulus tensor, G i and τ i are the modulus coefficient and relaxation time of the i-th order Prony series, respectively. Under uniaxial loading conditions, combined with the one-dimensional relaxation modulus expression of the generalized Maxwell viscoelastic model, assuming that the mechanical behavior of the viscoelastic element is isotropic, equation (4.16) can be simplified to the following form:

[0136] G(t)=G1I Vol +G2I Dev (4.17)

[0137] Where G1 and G2 are two independent relaxation coefficients: G1 = 3K, G2 = 2G. K and G are the bulk relaxation modulus and shear relaxation modulus, respectively. Assuming that Poisson's ratio ν is a constant and independent of time, the expressions for K and G are:

[0138] K=E(t) / [3(1-2ν)] (4.18)

[0139] G=E(t) / [2(1+ν)] (4.19)

[0140] For the particle-matrix interface dissociation model, in order to accurately describe the evolution process of dewetting damage at the particle-matrix interface, it is necessary to establish a reasonable interface failure criterion to determine the occurrence of interface damage. Currently, the commonly used failure criteria are mainly divided into two categories: stress criteria based on local stress state and energy criteria based on energy dissipation. Since it is very difficult to accurately solve the stress distribution of the particle-matrix interface during the loading process, in order to simplify the analysis process and effectively characterize the interface dissociation and dewetting behavior, this embodiment uses stress work as the energy criterion for driving interface dissociation. Considering that the hydrostatic stress is negative when the material is in a compressed state, the interface between the filling particles and the matrix is ​​subjected to compressive stress at this time, and the particles basically do not dewet. Assuming that the particle-matrix bonding interface basically does not fail under compression, define U +vis is the internal energy (internal energy density) per unit reference configuration volume of the viscoelastic element under triaxial tensile stress. Its expression is shown in equation (4.20), which is equal to the integral of stress power density over time:

[0141] U +vis =∫τ + :D vis dt(4.20)

[0142] By introducing the loading condition shown in equation (4.21), the effect of compressive stress on interface dissociation is filtered out.

[0143] tr(τ + )>0(4.21)

[0144] In the time interval [t, t+Δt], the incremental driving energy of interfacial dissociation acting on a single AP particle can be expressed as:

[0145]

[0146] Where N Pis a parameter reflecting the number of AP particles per unit volume in the reference configuration; γ is the energy transfer coefficient, which characterizes the rate at which the triaxial tensile stress work of the viscoelastic element is transferred to the particle-matrix interface. As the interfacial dissociation size d increases, the effective bonding area between the particle and the matrix decreases, and the energy transfer capacity decreases, with the coefficient γ decreasing accordingly. When the particles are completely dehumidified, energy transfer fails, and γ approaches zero. The energy transfer coefficient γ is calculated as follows:

[0147]

[0148] Where γ0 is the initial energy transfer coefficient (no interface dissociation state). is the relative dissociation length (ratio of dissociation length to particle size). The dehumidification area of ​​AP particles can be expressed as:

[0149]

[0150] Assume that the energy required to dissociate the AP particle-matrix bonding interface per unit area is G c , then the energy consumption of interfacial dissociation is U Diss =G c A. Energy consumption for establishing interfacial dissociation U Diss Energy of dissociation from the driving interface U +Particle The relationship between the energy barrier parameter U is introduced. Bar :

[0151] U Diss =U +Particle -U Bar (4.25)

[0152] It should be noted that under complex loading conditions, composite solid propellants can also experience varying degrees of microscopic damage under compression-shear or pure shear loads, including interfacial dewetting and microcrack propagation. To address the limitations of the aforementioned model, this example also introduces a microcrack propagation model. This combination of the dewetting model and the microcrack evolution model provides a more comprehensive description of the propellant's damage behavior under different stress states.

[0153] In the dewetting pore deformation model, the dewetting of AP particles within the propellant forms microscopic pores within the propellant. Under the continuous action of external loads, as the propellant matrix undergoes viscoelastic deformation, the morphology and volume of the dewetting pores also evolve over time, exhibiting viscoelastic-like mechanical behavior. To effectively characterize the time-varying characteristics of the pore volume and describe the material softening effect caused by the pores, this study uses a viscoelastic constitutive relation based on genetic integration to describe the volume evolution behavior of the pores:

[0154]

[0155] Where, Ev The Hencky strain tensor of the hole part is expressed as E v =ln(V v ). Mandel stress M v It is conjugate with the velocity gradient of the hole and its calculation is shown in Equation (4.12). v is the fourth-order tensor of the viscoelastic creep compliance of the hole, which can be expressed in the form of Prony series:

[0156]

[0157] In equation (4.27), J ∞ is the steady-state creep compliance tensor, J i and θ i are the compliance coefficients and relaxation times of each order of the Prony series. Under uniaxial loading conditions, the one-dimensional creep compliance, steady-state creep compliance, and the compliance coefficients of each order are J(t), J ∞ and J i The internal pores of a composite solid propellant primarily produce volumetric strain under load. The shear modulus of the pores can be set to 1.5 times that of the composite solid propellant, while the bulk modulus is 1% of that of the composite solid propellant. Assuming the creep characteristics of the pores are isotropic, Equation (4.27) can be written as Equation (4.28):

[0158] J v (t)=C1J1I Vol +C2J2I Dev (4.28)

[0159] In formula (4.28), J1 and J2 are two independent relaxation modulus functions:

[0160]

[0161] In formulas (4.29) and (4.30), is the volume creep compliance, is the shear creep compliance. Assume Poisson's ratio is constant. Then and for:

[0162]

[0163] In equation (4.28), the two coefficients C1 and C2 are used to characterize the proportional relationship between the initial volume creep compliance and initial shear creep compliance of the porous element before and after dehumidification and the compliance of the composite solid propellant. In equation (4.26), is the reduction factor. Considering that the effective modulus of the pores decreases and the creep compliance increases with the dissociation of the interface, the top-down Boltzmann growth function is used to represent the reduction in stiffness. The expression is:

[0164]

[0165] In the formula is the final stiffness reduction factor after complete interface dissociation, is the reference length corresponding to the fastest drop in stiffness, and ξ is the drop coefficient.

[0166] The SCRAM microcrack deformation evolution model, based on the microcrack damage mechanism, takes into account the different orientations of the microcrack surface normal direction and can describe the entire process of coin-shaped crack initiation, shearing, propagation, and aggregation. It is a statistical microcrack constitutive model. In the SCRAM microcrack propagation theory, the strain rates caused by various physical mechanisms can be superimposed, including different deformation behaviors of the material, such as elastic deformation, viscous flow, and microcrack propagation, as shown in Equation (4.34), where D represents the material's deformation rate tensor.

[0167]

[0168] The research results show that the orientation of microcracks has a significant effect on the macroscopic mechanical behavior of the material. When calculating the strain caused by microcrack extension, the orientation characteristics of the microcrack group should be fully considered, and the increment of the strain tensor should be the superposition of the strain components of the microcracks in different normal directions. This embodiment adopts the following simplified method: (1) A large number of microcracks of different sizes and normal directions are randomly distributed in the specimen. It is assumed that the number density of microcracks at the initial moment is isotropically distributed in space, and the number of microcracks follows an exponential distribution law as the size of the microcracks changes; (2) The influence of the microcrack nucleation effect is ignored; (3) The interaction effect between microcracks is not considered. The deformation rate caused by microcracks can be divided into two parts, as shown in formula (4.35):

[0169]

[0170] Where, represents the deformation rate tensor in the current configuration caused by all microcracks. Represents the deformation rate tensor caused by the opening or shearing of all microcracks. Since this part of the deformation rate does not take into account the expansion and evolution of microcracks, it is called the static crack deformation rate; represents the deformation rate tensor caused by the growth of all microcracks.

[0171] The tensile strain rate tensor caused by a set of uniformly distributed coin-shaped cracks with unit normal n and radius c is The calculation formula is shown in equations (4.36) to (4.38):

[0172]

[0173] In the above formula, The Jaumann rate representing the Kirchhoff stress.

[0174] The constant β = 8(1-υ) / (6G-3Gυ) is derived from the analytical solution for open and closed coin-shaped cracks, where G and v are the shear modulus and Poisson's ratio of the isotropic matrix (undamaged) material. In the subsequent analysis and numerical implementation, v is set to a constant, and the value of G is set to the tangent shear modulus of the viscoelastic element. n(c,n,t) is used to define the microcrack density function that takes into account the crack size and direction. n(c,n,t)ΔcΔψ represents the density of microcracks within a unit sphere with a radius between c and c+Δc and a unit normal n within a solid angle Δψ. τ n =n·τn is the normal component of the far-field Kirchhoff stress on the microcrack surface, and H is the Heaviside function (positive variables are 1, negative variables are 0). H[] = 1 indicates an open crack, and H[] = 0 indicates a closed crack. η in Equation (4.38) is the friction coefficient of the microcrack surface and the normal component τ of the far-field Kirchhoff stress on the microcrack surface. n and the tangential component τ s The expression is:

[0175]

[0176] The tangential component of Kirchhoff stress on the microcrack surface is:

[0177] τ s =[n·τ 2 n-(n·τn) 2 ] 12 (4.40)

[0178] In formula (4.39), is the friction coefficient of the microcrack surface. The angle brackets in equations (4.38) and (4.39) represent Macaulay brackets. For closed (shear) cracks τ n ≤0, formula (4.36) can be rewritten as:

[0179]

[0180] Fourth-order tensor c s for:

[0181] c s =b-2a(4.42)

[0182] Where a and b are expressed as:

[0183]

[0184] For the opening crack τ n >0, formula (4.41) can be written as:

[0185]

[0186] Where, the fourth-order tensor c o The expression is:

[0187] c o =b-νa (4.46)

[0188] The macroscopic tensile deformation rate caused by a collection of microcracks of different sizes and orientations can be obtained by summing Equation (4.36):

[0189]

[0190] In formula (4.47), the incremental solid angle Δψ in polar coordinates is the area of ​​the unit cell on the unit sphere:

[0191] Δψ=sinψΔθΔψ (4.48)

[0192] Considering that microcracks have symmetric characteristics in spatial distribution, half of the unit sphere is sufficient to characterize the orientation distribution of the crack. Therefore, the ranges of θ and ψ are set to: 0≤θ≤2π and 0≤ψ≤π / 2. By replacing the summation form of the crack radius in equation (4.47) with the integral form of the continuous distribution of the crack radius, the deformation rate can be derived. The following expression:

[0193]

[0194] In the above equation (4.49),

[0195]

[0196] Considering that each type of microcrack orientation within the propellant exhibits an independent density distribution function during loading, the characteristics of the derived anisotropic damage can be characterized by tracking the temporal evolution of these distribution functions. To facilitate the subsequent numerical implementation of the mechanical behavior of distributed microcracks, the continuous distribution of the crack direction n can be approximated by a finite number of discrete directions, and the hemisphere is divided into N equal-increment solid angles: Δψ = 2π / N. Considering the computational efficiency of secondary development of the constitutive model, in this embodiment, the surface normal of the microcracks on the hemisphere is discretized into 31 directions: N = 2×3×4+6+1, where 2 represents ψ = π / 6, π / 3; 3 represents θ = 0, π / 6, π / 3; 4 represents quadrants I, II, III, and IV; 6 represents ψ = π / 2; θ = π / 2, π / 3, π / 6, 0, -π / 6, -π / 3; and 1 represents ψ = 0.

[0197] The increase in crack size caused by crack growth also contributes to the deformation of the material, refer to formula (4.49). The deformation rate caused by crack growth is:

[0198]

[0199] This example uses high-precision micro-CT to scan and statistically analyze the initial microstructure of the propellant. Ten cross-sections along the height of the propellant microscopic scan sample were selected for analysis, and the distribution of pore sizes on each cross-section was statistically analyzed. The results show that the pore sizes in each cross-section closely follow a Weibull distribution. Assuming that the size distribution of microcracks with the same normal direction within the propellant during loading follows an exponential distribution, the probability density function can be expressed as:

[0200]

[0201] By substituting the above equation into equation (4.50), we can obtain:

[0202]

[0203] In equations (4.52) to (4.54), and are the average radius and average microcrack growth velocity of all microcracks with normal n at time t, respectively. N0(n,t) is a parameter that characterizes the microcrack density. Since the model constructed in this paper ignores the effect of microcrack nucleation and assumes that the solid propellant is isotropic in its initial unloaded state, N0(n,t) is a constant that is independent of time t and microcrack direction n.

[0204] Existing experimental results show that there is a power-law relationship between the crack growth rate and the type I stress intensity factor. The fracture performance of HTPB propellant at a tensile rate in the range of 5-500mm / min was further studied. The study showed that HTPB propellant has an obvious blunted crack tip during the fracture process. By improving the Schapery exponential equation, an empirical equation describing the crack growth rate of HTPB propellant was proposed, which showed a good fit with the experimental data. Taking into account the load dependence of microcrack growth in propellant: when the stress or energy release rate is lower than the critical level of instability, the crack usually exhibits a low-speed stable growth; when the stress or energy release rate exceeds the critical value, the crack growth will enter an unstable state. This embodiment adopts the microcrack growth rate expression form given therein, which is specifically described as follows:

[0205]

[0206] is a line with normal direction n and size The energy release rate of the crack, the critical energy release rate g c =2γ, γ is the fracture surface energy. R are the parameters describing the maximum propagation velocity of microcracks, m, g1 and g tr is the model parameter. According to the continuity of equation (4.55), we can get:

[0207] g tr =(1+1 / m)g c (4.56)

[0208] g1=(m+1) 1m (1+1 / m)g c (4.57)

[0209] For coin-shaped microcracks, the energy release rate The specific form of is related to the normal direction of the microcrack surface and the stress state at the location of the microcrack. It can be expressed as

[0210]

[0211] In equation (4.58), the parameters G and v have the same meanings as defined in Section 4.2.5.1. f(τ,n) is a function of stress and depends on whether the microcrack is open or closed.

[0212]

[0213] It can be seen from the above-mentioned SCRAM microcrack deformation evolution model that for a large number of microcracks in different directions distributed in the HTPB propellant, under the action of far-field three-dimensional stress, the open or closed state of the microcracks can be determined by calculating the normal stress component of the microcrack surface. Microcracks in different directions have different expansion rates, so the evolution of the microcrack size is closely related to its normal direction and stress state. Through equations (4.49) and (4.51), the deformation rates caused by microcracks in different normal directions can be summed to obtain the additional deformation rate caused by the expansion of all microcracks on a macro scale. This microcrack deformation evolution model takes into account the statistical distribution characteristics of microcrack size and direction, establishes a quantitative relationship between microscopic microcrack damage and macroscopic mechanical response, and can effectively describe the anisotropic damage evolution mechanical behavior of the material.

[0214] To determine the model parameters and verify the accuracy of the constitutive model in predicting the change in the propellant's Poisson's ratio, it is necessary to simultaneously measure the stress, longitudinal strain, and transverse strain of the specimen during uniaxial tension. A rectangular area measuring 10 mm (width) by 30 mm (length) in the middle of the specimen is selected as the analysis area for Poisson's ratio calculation. The specific data processing process is as follows:

[0215] Draw vertical and horizontal center guides through the center of the rectangular area;

[0216] Set m (m=11 in this study) equidistant line segments along the longitudinal direction; set n (n=31 in this study) equidistant line segments along the transverse direction;

[0217] According to the change in the length of each longitudinal and transverse line segment before and after deformation, the corresponding logarithmic strain is calculated:

[0218]

[0219] Where, and are the lengths of each longitudinal and transverse line segment before deformation, L m and W m is the corresponding length after deformation.

[0220] Calculate the mean effective strains in the longitudinal and transverse directions:

[0221]

[0222] Calculate the instantaneous Poisson's ratio of the propellant based on the average longitudinal and transverse effective strains:

[0223]

[0224] As can be seen from the above, the total deformation gradient of the material is decomposed into the product of the deformation gradients of the viscoelastic component, the dewetting pore damage component, and the microcrack component. The model includes four physical mechanisms within the propellant during loading: stress relaxation behavior, particle-matrix interface dissociation behavior, dewetting pore deformation, and microcrack deformation evolution. Therefore, the parameters of the propellant damage constitutive model based on the microscopic dewetting and microcrack evolution mechanism can also be divided into four categories: (1) viscoelastic parameters: relaxation modulus; (2) interface dewetting parameters: including interface strength, critical dissociation energy, etc.; (3) pore evolution parameters: including creep compliance of pores, reduction coefficient, etc.; (4) microcrack parameters: including crack density, expansion rate related parameters, etc.

[0225] Since the constitutive model constructed in this embodiment contains multiple undetermined parameters, it is necessary to use an effective method to obtain the specific values ​​of all parameters of the model. This embodiment uses a combination of experimental testing, literature review, and inversion identification methods to determine the parameters in the model. The specific method is as follows:

[0226] (1) Determine the parameters of the viscoelastic element through relaxation experiments, including the coefficients of each order of the Prony series of relaxation modulus and relaxation time;

[0227] (2) Using the relaxation modulus E(t) of the viscoelastic element and the conversion relationship between the relaxation modulus and creep compliance J(t), the creep compliance parameter of the dewetting hole deformation is obtained:

[0228]

[0229] (3) The number of AP particles per unit volume in the reference configuration N P and the equivalent particle size d were determined based on experimental data in Ref.

[0230] (4) The critical energy value for dissociation of the particle-matrix interface per unit area is based on the previous research results of this research group.

[0231] In addition, there are 16 parameters that need to be obtained through inversion of the optimization algorithm, including Poisson's ratio parameter v, the original energy transfer coefficient γ0 of interface dissociation, and the energy barrier parameter U Bar , reduction coefficient related parameters ξ and Four constant coefficients C1 and C2 (the values ​​of C1 and C2 are different before and after interface dissociation), the number density of microcracks in the initial state N0(n,t), the average length of microcracks in the initial state Parameters related to microcrack propagation velocity c R and m, the critical energy release rate g for microcrack propagation in the model c and microcrack surface friction coefficient

[0232] Select 0.01, 0.05 and 0.5s -1 The stress-strain data and Poisson's ratio data under strain rate are used as inversion data sets to determine the model parameters. In addition, 0.001, 0.15 and 1.0s -1 The experimental results under strain rate are used as a validation data set to verify the accuracy of the model. The process of determining the constitutive model parameters includes setting the initial value of material parameters, iterative solution of optimization algorithm, model verification and parameter adjustment, and final parameter determination. The complete process is as follows: Figure 5 As shown:

[0233] Since many model parameters need to be determined using the inversion identification method, it is very important to adopt a reliable and efficient parameter determination algorithm. Genetic Algorithm (GA), as a global optimization algorithm based on the principle of biological evolution, has the advantages of simple coding, strong adaptability, parallel computing and global search. However, in practical applications, traditional GA has the limitations of being easily trapped in local optimal solutions too early and being parameter sensitive. To improve the performance of GA, this embodiment adopts the following improvement strategy:

[0234] (1) The performance of GA depends largely on the design of the fitness function. The crossover and mutation operations are based on the fitness value of the individual. The fitness value of each individual in the population is used to evaluate the quality of the solution. The larger the fitness value, the higher the quality of the solution, and the greater the probability that the individual will be selected for reproduction. Therefore, the reasonable design of the fitness function has a decisive influence on the computational efficiency of GA and the acquisition of the global optimal solution. Generally, the fitness function can be obtained by performing appropriate mapping transformations on the objective function. In this study, the objective function for solving the constitutive model parameters is defined as:

[0235]

[0236] Where x=(x1,x2,…,x m ) is the parameter vector to be determined, and m is the number of parameters; and are the predicted stress and experimental stress of the jth data point, respectively; l is the total number of experimental conditions; n k is the number of data points under the kth experimental condition.

[0237] The fitness function not only affects the convergence speed of the algorithm, but also directly affects the ability to search for the global optimal solution. By introducing a fitness value adjustment mechanism, premature convergence can be effectively overcome and the algorithm's search efficiency can be improved. Based on the above considerations, Equation (4.64) is transformed and the proposed fitness function is as follows:

[0238]

[0239] Where c max = [f(x) / (n×l)] 1 / 2 According to the mathematical properties and physical meaning of the objective function, this embodiment takes c max =100.

[0240] (2) Mutation plays an important role in GA. In this embodiment, an improved computational expression based on non-uniform mutation is used to improve the search capability of the genetic operator in the entire population space:

[0241]

[0242] Where K 0i and K i are the chromosomes of the parents and offspring respectively. i and U i K i The upper and lower bounds of . g is the current evolutionary generation. g max It is a parameter used to adjust the search range of the mutation operator. Usually, this parameter is taken as the maximum evolution generation. α, β and δ are independent random numbers uniformly distributed between (0, 1).

[0243] Compared with the prior art, the method for constructing anisotropic damage constitutive model of propellant provided in this embodiment achieves deep coupling of microscopic and macroscopic mechanical behavior, characterizes anisotropic damage, and improves the applicability and predictive ability of the model by comprehensively integrating the microscopic damage mechanism of the propellant and improving the parameter identification algorithm. The constructed constitutive model can not only accurately predict the macroscopic stress-strain response of particle-reinforced composite materials, but also reveal the variation law of microscopic characteristic parameters such as the degree of particle dewetting and the degree of microcrack extension, and quantitatively analyze the volume change of the specimen and the change of microscopic structural parameters during loading. In addition, the model only requires a Poisson's ratio constant to effectively describe the strain dependence and strain rate dependence of the Poisson's ratio of composite solid propellants during tensile loading. It is applicable to a wider range of stresses and loading rates, and improves the accuracy and reliability of the propellant damage constitutive model.

[0244] It should be understood that although Figure 2 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 2 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0245] To facilitate the implementation of the anisotropic damage constitutive model construction method for propellants according to the embodiments of the present application, the embodiments of the present invention further provide an apparatus for constructing an anisotropic damage constitutive model for propellants based on the aforementioned anisotropic damage constitutive model construction method for propellants. The meanings of the terms herein are the same as those in the aforementioned anisotropic damage constitutive model construction method for propellants. For specific implementation details, please refer to the description in the method embodiments.

[0246] See also Figure 6 , Figure 6 This is a schematic diagram of the structure of the anisotropic damage constitutive model construction device for propellant provided in an embodiment of the present application. The anisotropic damage constitutive model construction device for propellant may specifically include a first construction module 201, a second construction module 202, and a third construction module 203, which may be specifically as follows:

[0247] Framework module 201 is used to decompose the total deformation gradient of the propellant into the product of the linear viscoelastic deformation gradient and the damage deformation gradient based on the multiplicative decomposition theory of deformation gradient, and establish a multi-scale damage evolution framework;

[0248] The coupling module 202 is used to construct a viscoelastic response model, a particle interface dissociation model, a dewetting hole deformation model, and a microcrack statistical evolution model within the multi-scale damage evolution framework, and couple the stress power contribution of each model to form a comprehensive damage constitutive equation;

[0249] Optimization module 203 is used to obtain macroscopic mechanical response data and microscopic structural evolution data of the propellant through tensile tests at different strain rates, and to perform inverse optimization on the model parameters of the comprehensive damage constitutive equation using an improved genetic algorithm;

[0250] The construction module 204 is used to determine the constitutive model for quantitatively characterizing the coupling relationship between the anisotropic damage of the propellant, the microstructure evolution and the macroscopic mechanical response based on the model parameters after inversion optimization.

[0251] Optional, such as Figure 7 As shown, in some embodiments, the apparatus for constructing anisotropic damage constitutive model of propellant may further include a verification module 205, which is specifically used to:

[0252] Real-time measurement of the full-field strain data of the propellant, including longitudinal strain data and lateral strain data;

[0253] The prediction accuracy of the constitutive model for Poisson's ratio strain correlation and strain rate sensitivity is verified based on full-field strain data.

[0254] The specific definition of the anisotropic damage constitutive model construction device for propellants can be found in the definition of the anisotropic damage constitutive model construction method for propellants mentioned above, and will not be repeated here. The various modules in the above-mentioned anisotropic damage constitutive model construction device for propellants can be implemented in whole or in part through software, hardware, and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the corresponding operations of the above modules.

[0255] The apparatus for constructing an anisotropic damage constitutive model of a propellant provided in this embodiment first decomposes the total deformation gradient into the product of the linear viscoelastic deformation gradient and the damage deformation gradient through a multiscale damage evolution framework based on the multiplicative decomposition theory of deformation gradients, thereby achieving deep coupling between the microscopic damage mechanism and the macroscopic mechanical response. Then, by separately constructing a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model, and a microcrack statistical evolution model, and coupling the stress-power contributions of each model, a comprehensive damage constitutive equation is formed, which comprehensively integrates multiple microscopic damage mechanisms. Next, combining tensile test data at different strain rates with an improved genetic algorithm, the model parameters are inversely optimized to ensure their accuracy and reliability. Finally, based on the inverse-optimized model parameters, a constitutive model is output that can comprehensively characterize the coupling relationship between the anisotropic damage of the propellant, the microscopic structural evolution, and the macroscopic mechanical response.

[0256] In addition, the present invention also provides an electronic device, such as Figure 8 , which shows a schematic structural diagram of an electronic device involved in an embodiment of the present application, specifically:

[0257] The electronic device may include one or more processors 301 of processing cores, one or more computer-readable storage media memories 302, a power supply 303, an input unit 304 and other components. Those skilled in the art will appreciate that Figure 8 The electronic device structure shown in the figure does not constitute a limitation of the electronic device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange components differently.

[0258] The processor 301 is the control center of the electronic device. It connects all parts of the electronic device using various interfaces and lines. By running or executing software programs and / or modules stored in the memory 302 and accessing data stored in the memory 302, it performs various functions of the electronic device and processes data, thereby monitoring the electronic device as a whole. Optionally, the processor 301 may include one or more processing cores; preferably, the processor 301 may integrate an application processor and a modem processor, wherein the application processor primarily processes the operating system, user interface, and application programs, while the modem processor primarily handles wireless communications. It is understood that the modem processor may not be integrated into the processor 301.

[0259] The memory 302 can be used to store software programs and modules. The processor 301 executes various functional applications and a method for constructing anisotropic damage constitutive models of propellants by running the software programs and modules stored in the memory 302. The memory 302 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area may store data created based on the use of the electronic device, etc. In addition, the memory 302 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage device. Accordingly, the memory 302 may also include a memory controller to provide the processor 301 with access to the memory 302.

[0260] The electronic device also includes a power supply 303 for supplying power to various components. Preferably, the power supply 303 can be logically connected to the processor 301 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The power supply 303 can also include one or more DC or AC power supplies, a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator, and other arbitrary components.

[0261] The electronic device may further include an input unit 304, which may be configured to receive input digital or character information and generate keyboard, mouse, joystick, optical or trackball signal inputs related to user settings and function control.

[0262] Although not shown, the electronic device may further include a display unit, etc., which will not be described in detail here. Specifically, in this embodiment, the processor 301 in the electronic device will load the executable files corresponding to the processes of one or more application programs into the memory 302 according to the following instructions, and the processor 301 will run the application programs stored in the memory 302 to implement various functions as follows:

[0263] Based on the theory of multiplicative decomposition of deformation gradients, the total deformation gradient of the propellant is decomposed into the product of the linear viscoelastic deformation gradient and the damage deformation gradient, and a multiscale damage evolution framework is established. Within the multiscale damage evolution framework, a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model, and a microcrack statistical evolution model are constructed respectively, and the stress power contribution of each model is coupled to form a comprehensive damage constitutive equation. The macroscopic mechanical response data and microscopic structural evolution data of the propellant are obtained through tensile tests at different strain rates, and the model parameters of the comprehensive damage constitutive equation are inversely optimized using an improved genetic algorithm. Based on the inverse-optimized model parameters, a constitutive model is determined to quantitatively characterize the coupling relationship between the anisotropic damage, microscopic structural evolution, and macroscopic mechanical response of the propellant.

[0264] The specific implementation of the above operations can be found in the previous embodiments and will not be repeated here.

[0265] The embodiments of the present application decompose the total deformation gradient into the product of the linear viscoelastic deformation gradient and the damage deformation gradient through a multiscale damage evolution framework based on the multiplicative decomposition theory of deformation gradients, thereby achieving deep coupling of the microscopic damage mechanism and the macroscopic mechanical response. By separately constructing a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model, and a microcrack statistical evolution model, and coupling the stress-power contribution of each model, a comprehensive damage constitutive equation is formed to fully integrate multiple microscopic damage mechanisms. The model parameters are inversely optimized by combining tensile test data at different strain rates and an improved genetic algorithm to ensure the accuracy and reliability of the model parameters. Based on the inverse-optimized model parameters, a constitutive model is output that can comprehensively characterize the coupling relationship between the anisotropic damage of the propellant, the microscopic structural evolution, and the macroscopic mechanical response.

[0266] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be accomplished by instructions, or by controlling related hardware through instructions. The instructions may be stored in a computer-readable storage medium and loaded and executed by a processor.

[0267] To this end, an embodiment of the present application provides a storage medium storing a plurality of instructions that can be loaded by a processor to execute the steps of any of the methods for constructing anisotropic damage constitutive models of propellants provided in the embodiments of the present application. For example, the instructions can execute the following steps:

[0268] Based on the theory of multiplicative decomposition of deformation gradients, the total deformation gradient of the propellant is decomposed into the product of the linear viscoelastic deformation gradient and the damage deformation gradient, and a multiscale damage evolution framework is established. Within the multiscale damage evolution framework, a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model, and a microcrack statistical evolution model are constructed respectively, and the stress power contribution of each model is coupled to form a comprehensive damage constitutive equation. The macroscopic mechanical response data and microscopic structural evolution data of the propellant are obtained through tensile tests at different strain rates, and the model parameters of the comprehensive damage constitutive equation are inversely optimized using an improved genetic algorithm. Based on the inverse-optimized model parameters, a constitutive model is determined to quantitatively characterize the coupling relationship between the anisotropic damage, microscopic structural evolution, and macroscopic mechanical response of the propellant.

[0269] The specific implementation of the above operations can be found in the previous embodiments and will not be repeated here.

[0270] The storage medium may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0271] Since the instructions stored in the storage medium can execute the steps in the method for constructing an anisotropic damage constitutive model of any propellant provided in the embodiments of the present application, the beneficial effects that can be achieved by the method for constructing an anisotropic damage constitutive model of any propellant provided in the embodiments of the present application can be achieved. Please refer to the previous embodiments for details and will not be repeated here.

[0272] The above is a detailed introduction to the method for constructing an anisotropic damage constitutive model of a propellant and the related equipment provided in the examples of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above examples is only used to help understand the method and core ideas of the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present application.

Claims

1. A method for constructing an anisotropic damage constitutive model of a propellant, characterized in that: The steps include: Based on the theory of multiplicative decomposition of deformation gradient, the total deformation gradient of the propellant is decomposed into the product of the linear viscoelastic deformation gradient and the damage deformation gradient, and a multi-scale damage evolution framework is established. Within the multi-scale damage evolution framework, a viscoelastic response model, a particle interface dissociation model, a dewetting pore deformation model, and a microcrack statistical evolution model are constructed respectively, and the stress power contributions of each model are coupled to form a comprehensive damage constitutive equation; The macroscopic mechanical response data and microscopic structural evolution data of the propellant are obtained through tensile tests at different strain rates, and the model parameters of the comprehensive damage constitutive equation are inversely optimized using an improved genetic algorithm. Based on the model parameters after inversion optimization, a constitutive model is determined to quantitatively characterize the coupling relationship between propellant anisotropic damage, mesoscopic structural evolution and macroscopic mechanical response.

2. The method for constructing an anisotropic damage constitutive model of a propellant according to claim 1, characterized in that: Based on the theory of multiplicative decomposition of deformation gradient, the total deformation gradient of the propellant is decomposed into the product of the linear viscoelastic deformation gradient and the damage deformation gradient, and a multi-scale damage evolution framework is established, including: defining an initial configuration, an intermediate configuration of hole damage, and an intermediate configuration of crack damage of the propellant, and decomposing a total deformation gradient into a product of a linear viscoelastic deformation gradient and a damage deformation gradient; Further decomposing the damage deformation gradient into the product of the hole deformation gradient and the crack gradient; Based on the decomposition results, a multi-scale damage evolution framework is established to integrate mesoscopic damage and macroscopic mechanical response.

3. The method for constructing an anisotropic damage constitutive model of a propellant according to claim 1, characterized in that: The construction of the particle interface dissociation model includes: The driving energy of particle-matrix interface dissociation is defined based on the stress work criterion to filter the effect of compressive stress on interface dissociation; A dynamically decaying energy transfer coefficient is introduced, which decays exponentially with increasing interface dissociation length, to characterize the inhibitory effect of the interface dissociation degree on energy transfer.

4. The method for constructing an anisotropic damage constitutive model of a propellant according to claim 1, wherein: The construction of the microcrack statistical evolution model includes: Based on the statistical crack mechanics theory, it is assumed that the microcrack size obeys an exponential distribution, and the normal direction of the microcrack is discretized into a finite number of discrete directions; The power-law relationship between microcrack growth rate and energy release rate is defined, and the microcrack size and direction distribution are dynamically updated by combining the crack surface friction coefficient and critical energy release rate.

5. The method for constructing anisotropic damage constitutive model of propellant according to claim 1, characterized in that: The inverse optimization of the model parameters of the comprehensive damage constitutive equation using an improved genetic algorithm includes: The fitness function is designed as the weighted square sum of experimental stress data and model prediction values, and a non-uniform mutation strategy is introduced to adjust the range of chromosome variation. Through the joint inversion of tensile test data under multiple strain rates, the viscoelastic parameters, interface dissociation parameters, pore evolution parameters and microcrack parameters are simultaneously optimized to obtain the corresponding global optimal solution.

6. The method for constructing anisotropic damage constitutive model of propellant according to claim 1, characterized in that: The constitutive model for quantitatively characterizing the coupling relationship between anisotropic damage, microstructure evolution and macroscopic mechanical response of the propellant is determined based on the model parameters after inversion optimization, including: Substituting the inverse-optimized model parameters into the comprehensive damage constitutive equation, coupling the viscoelastic stress, pore softening stress, and microcrack anisotropic stress components; Based on the dynamic update mechanism of mesoscopic damage parameters, the quantitative relationship between macroscopic stress-strain response, particle dewetting degree and microcrack propagation path is output in real time.

7. The method for constructing anisotropic damage constitutive model of propellant according to claim 1, characterized in that: The method further comprises: measuring full-field strain data of the propellant in real time, wherein the full-field strain data includes longitudinal strain data and lateral strain data; The prediction accuracy of the constitutive model for Poisson's ratio strain correlation and strain rate sensitivity is verified based on the full-field strain data.

8. A device for constructing anisotropic damage constitutive model of propellant, characterized in that: include: The framework module is used to decompose the total deformation gradient of the propellant into the product of the linear viscoelastic deformation gradient and the damage deformation gradient based on the multiplicative decomposition theory of deformation gradient, and establish a multi-scale damage evolution framework; A coupling module is used to construct a viscoelastic response model, a particle interface dissociation model, a dewetting hole deformation model, and a microcrack statistical evolution model within the multi-scale damage evolution framework, and couple the stress power contribution of each model to form a comprehensive damage constitutive equation; An optimization module is used to obtain macroscopic mechanical response data and microscopic structural evolution data of the propellant through tensile tests at different strain rates, and to perform inverse optimization of the model parameters of the comprehensive damage constitutive equation using an improved genetic algorithm; A building module is used to determine the constitutive model for quantitatively characterizing the coupling relationship between propellant anisotropic damage, mesostructure evolution and macromechanical response based on the model parameters after inversion optimization.

9. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for constructing an anisotropic damage constitutive model of a propellant according to any one of claims 1 to 7 are implemented.

10. A storage medium, characterized in that: The invention stores a computer program that can be loaded by a processor and executes the method for constructing an anisotropic damage constitutive model of a propellant according to any one of claims 1 to 7.

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