A method for simulating bulk ablation of short fiber reinforced ablative materials

Abstract

The application discloses a short-fiber reinforced ablative material bulk ablation simulation method, and belongs to the technical field of multifunctional composite materials and structure numerical simulation.The application comprises the following steps: constructing a discrete system composed of a series of spherical particle units by using a discrete element method; calculating the contact area, contact force and connecting force of the particle units by using a Hertz-Mindlin contact model and a parallel-bond model at each calculation time step; calculating the temperature of the particle units by using an energy conservation principle and a Fourier heat conduction law; calculating the displacement and angular displacement of the particle units by continuously integrating the momentum conservation equation twice; updating the velocity, displacement and diameter of each particle unit, and updating the porosity and pore pressure of the discrete system; iteratively solving and visualizing until a specific condition is met, and ending the simulation.The application characterizes the internal structure features of the short-fiber reinforced ablative material by using the discrete element method, so that the numerical simulation accuracy of the ablation process is improved, and the possibility of capturing the micro ablation mechanism is provided.

Description

Technical Field

[0001] This invention belongs to the field of numerical simulation technology of multifunctional composite materials and structures, and specifically relates to a method, program, storage medium and device for simulating the bulk ablation of short fiber reinforced ablation materials. Background Technology

[0002] Short fiber reinforced ablation materials undergo a series of complex physicochemical changes during heating, and numerical simulation of the ablation process is one of the main technical means to explore its internal mechanism. With the deepening research on ablation theory, typical ablation phenomena such as thermal diffusion, carbon deposition, and thermal expansion of ablation materials have received sufficient attention and a large amount of research has been carried out.

[0003] The reaction kinetics of carbon deposition are highly complex. It is generally believed that the residence time of pyrolysis gases, gas escape viscosity, and internal oxygen content are the main influencing factors. Simultaneously, carbon deposition and carbon oxidation compete with each other, jointly determining the porosity and density of the material's microstructure. Duffa et al. studied the relationship between deposition reactions and the specific surface area of ​​the microstructure. JiangxiLi et al. observed "dense / loose" and "loose / dense / loose" structural features within ablated materials and analyzed their formation mechanism, pointing out that microstructure characteristics have a significant impact on the accuracy of numerical models. Natali et al. considered material expansion, carbon deposition reactions, and the mechanical properties of the elastic matrix in their numerical models. Their research showed that without considering thermal expansion and thermal deposition, the simulated values ​​were lower than the measured values; however, introducing thermal expansion and thermal deposition factors confirmed material densification and yielded temperature curves that agreed well with the measured results.

[0004] The main reasons for thermal expansion are twofold: first, the temperature gradient induces thermal strain in the ablation material; second, the obstruction of pyrolysis gas flow creates pressure within the material. Thermal expansion of the ablation material prolongs the heat transfer path, affecting the material's temperature field and ablation rate. Experiments conducted by Shi Shengbo's research team at Northwestern Polytechnical University on silicon fiber reinforced phenolic resin composites have confirmed that thermal expansion significantly impacts the material's temperature field: the temperature data obtained in the numerical model considering and not considering thermal expansion differ by approximately 50°C; moreover, in oxygen-acetylene ablation experiments (cold wall heat flux approximately 2–3 MW / m²), the thermal expansion is significantly greater. 2 The results (lasting 200 s) showed a pressure peak of approximately 60 atm inside the material, which caused the material to expand. Cracks and spalling due to internal pressure are also common failure modes in resin-based composites under high heating rates.

[0005] In summary, the numerical simulation studies of fiber-reinforced ablation materials reveal several key issues. Regarding model scale, neglecting or abstracting the pore structure of the ablation material fails to accurately capture the crucial factors influencing its thermal response, and the simulation results rely to some extent on pre-existing assumptions about the microstructure's geometric parameters. As for model dimensionality, considering the significantly larger temperature gradient perpendicular to the surface compared to other directions, a one-dimensional ablation model is suitable for describing the heat conduction process of homogeneous materials. However, when considering the heterogeneous characteristics of fiber-reinforced composites, the model must be extended to two or three dimensions. Furthermore, since fiber diameter and pore size are close to the mean free path of gases, numerical models that ignore the material's microstructure based on continuity assumptions are not strictly accurate. Summary of the Invention

[0006] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a volume ablation simulation method for short fiber reinforced ablation materials. The discrete element method is used to characterize the internal structural features of short fiber reinforced ablation materials, thereby improving the accuracy of numerical simulation of the ablation process and providing the possibility of capturing the microscopic ablation mechanism.

[0007] The technical solution of this invention is: a method for simulating the bulk ablation of short fiber reinforced ablation materials, comprising:

[0008] S1, using the discrete element method to construct short fiber reinforced ablation material into a discrete system composed of a series of spherical particle units;

[0009] S2, at each calculation time step, the contact area, contact force and bonding force of the particle element are calculated using the Hertz-Mindlin contact model and the parallel-bond model;

[0010] S3 calculates the temperature of the particle unit using the principle of energy conservation and Fourier's law of thermal conductivity;

[0011] S4 calculates the displacement and angular displacement of the particle unit by integrating the momentum conservation equation twice; updates the velocity, displacement, and diameter of each particle unit, and updates the porosity and pore pressure of the discrete system.

[0012] S5 iterates through the solution and visualization until a specific condition is met, at which point the simulation ends.

[0013] Further, S1 includes:

[0014] Using N randomly arranged spherical particle units b i m The matrix material phase of the short fiber reinforced ablation material is represented by M clustered spherical particle units b. i fRepresenting the short fiber phase, N+M particle units are closely arranged in the computational domain to construct a discrete system that characterizes the porous and heterogeneous structural features of ablation materials.

[0015] Further, S2 includes:

[0016] At each calculation time step, the Hertz-Mindlin contact model was used to calculate the value of each particle element b. i The contact area and contact force at the contact point are determined using the parallel-bond model in particle element b. i m Between, b i f Between, and b i m and b i f Connecting units are established between particles, and the connecting force at each connection is calculated. Once particles come into contact, a contact force is generated. Once a connecting unit breaks, it will not reconnect or generate a connecting force.

[0017] Further, S3 includes:

[0018] At each calculation time step, particle element b i Based on temperature, it is divided into carbonized layer particle units b i C , intact layer particle unit b i V and pyrolysis layer particle unit b i P Fourier thermal conductivity differential equations are established for the three types of particle units, and the temperature of each particle unit is solved under given initial conditions and second-type boundary conditions.

[0019] Furthermore, in S4, the linear change of particle unit diameter with temperature at the microscopic level is used to describe the thermal expansion of the material at the macroscopic level, and the linear change of particle unit diameter with pore pressure at the microscopic level is used to describe the carbon deposition of the material at the macroscopic level.

[0020] Furthermore, in S5, the iterative solution step includes:

[0021] a) Retrieve all contact pairs in the computational domain based on the position and diameter of the particle unit at the current time step;

[0022] b) Update the contact area, contact force, and connection force of the particle unit;

[0023] c) Update the temperature of the particle unit;

[0024] d) Update the displacement and angular displacement of the particle units; update the velocity, displacement, and diameter of each particle unit; update the porosity and pore pressure of the discrete system;

[0025] e) Update the visualization of the computing domain.

[0026] Furthermore, in S5, the specific conditions include: the given second type of boundary conditions have been loaded, the set number of calculation steps has been reached, and the particle temperature exceeds the allowable temperature value.

[0027] A bulk ablation simulation system for short fiber reinforced ablation materials includes:

[0028] The geometric modeling module is used to construct discrete systems in the computational domain, specifying matrix material phase particle units and short fiber phase particle units;

[0029] The mechanical modeling module is used to establish connection units between particle units of the same phase and different phases;

[0030] The mechanical calculation module is used for contact detection and to calculate the forces acting on particle units.

[0031] The ablation calculation module is used to calculate the temperature of the particle unit;

[0032] The motion update module is used to calculate the position and diameter of particle units; and the porosity and pore pressure of the discrete system.

[0033] The visualization module is used to refresh and display the visualization scene of the computing domain.

[0034] A computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of a volume ablation simulation method for a short fiber reinforced ablation material.

[0035] A volume ablation simulation device for a short fiber reinforced ablation material includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the volume ablation simulation method for the short fiber reinforced ablation material.

[0036] The advantages of this invention compared to the prior art are:

[0037] This invention intuitively expresses the porous and heterogeneous structural characteristics of short fiber reinforced ablation materials, enabling observation of the internal structural evolution of the ablation process of the ablation material, thereby improving the accuracy of numerical simulation and providing the possibility of capturing the microscopic ablation mechanism. Attached Figure Description

[0038] Figure 1 This is a flowchart of the method of the present invention;

[0039] Figure 2This is a schematic diagram of a discrete system composed of spherical particle units constructed using the discrete element method in an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the carbon deposition physical model in an embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram of the thermal expansion physical model in an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the functional modules of the volume ablation simulation program for short fiber reinforced ablation materials in an embodiment of the present invention. Detailed Implementation

[0043] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0044] The following description, in conjunction with the accompanying drawings, provides a more detailed explanation of a bulk ablation simulation method for short fiber reinforced ablation materials provided in this application. Specific implementation methods may include (e.g.) Figures 1-5 As shown):

[0045] In the solution provided in the embodiments of this application, the two-dimensional circular particle discrete unit method is used for illustration. The ablation material is specifically a methyl silicone rubber ablation material reinforced with short-cut carbon fibers. Bulk ablation refers to the thermal diffusion, thermal expansion and carbon deposition phenomena that occur inside the material after the temperature reaches and exceeds the pyrolysis temperature of the material.

[0046] Figure 1 This is a flowchart of a bulk ablation simulation method for short fiber reinforced ablation materials according to an embodiment of this application. The method includes the following steps:

[0047] S1 uses the discrete element method to construct a discrete system of short fiber reinforced ablation materials into a series of spherical particle units.

[0048] Electron microscopy is generally used to analyze the three-dimensional microstructure of short fiber reinforced ablation material samples in order to determine the filling parameters of the geometric model and the porosity Ф of the specimen.

[0049]

[0050] Among them, S pi It is the sum of the pore areas on the cross-section of the specimen, where S is the cross-sectional area of ​​the specimen. In this embodiment, the measured porosity Ф = 12%–23%.

[0051] Using the discrete volume filling algorithm proposed by Leclerc et al. [Leclerc, W., et al. Adv. Eng. Softw, 2014, 77: 1-12.], 286 circular particles were filled into an 80mm × 80mm square computational domain. The particle diameters followed a normal distribution on the interval [3mm, 7mm]. Figure 2 As shown, there are 274 randomly arranged spherical particle units b i m This represents the matrix phase of the short fiber reinforced ablation material, consisting of 12 clustered spherical particle units, each with a diameter of 5 mm. i f This indicates a short fiber phase, where the filling state of all particle units is random and compact, and the average contact number of particle units is 3.5.

[0052] S2, at each calculation step, the contact area, contact force, and bonding force of the particle element are calculated using the Hertz-Mindlin contact model and the parallel-bond model.

[0053] At a certain calculation time step, if two particle units b i and b j The distance between them is l bi-j The relationship between the particle radius R and the particle radius is expressed by equation l. bi-j <(R bi +R bj Then they come into contact with each other, and the b of each particle unit is calculated using the Hertz-Mindlin contact model. i The contact area S at the contact point * Normal contact force F n c and tangential contact force F t c :

[0054]

[0055]

[0056]

[0057] Where, r * E is the equivalent contact radius of the particle unit. * It is the equivalent elastic modulus, G * It is the equivalent shear modulus, m * It is the equivalent mass, δ n It is the overlap of particle units, v n vel and v t velThese are the relative normal velocity and relative tangential velocity of the particle unit, respectively.

[0058] In this embodiment, the parallel-bond model is used in particle unit b. i m Between, b i f Between, and b i m and b i f Establish connection elements between them, and use normal connection stiffness k for the connection elements. n b Tangential connection stiffness k s b The ultimate tensile strength of the material σ c and material shear strength limit τ c Definition: Normal connecting force F n b and tangential connection force F t b They are respectively:

[0059]

[0060]

[0061] Where A is the cross-sectional area of ​​the contact region of the particle unit, A = 2Rt, and in this embodiment, the thickness of the two-dimensional circular particle is t = 1; Δδ n and Δδ t These are the relative normal displacement and relative tangential displacement of the particle element in the current calculation step. If the calculated tensile stress σ between the particle elements... i Or shear stress τ i Exceeding the tensile strength limit σ of the material c Or the material's shear strength limit τ c If this happens, the connection unit will fail.

[0062] Once the particle units come into contact, a contact force is generated. Once the connecting unit fails, it will not reconnect or generate a connecting force.

[0063] S3 calculates the temperature of the particle unit using the principle of energy conservation and Fourier's law of thermal conductivity.

[0064] At each calculation time step, particle element b i According to temperature T i It is divided into carbonized layer particle units b i C (T i >T p +δT), intact layered particle unit b iV (T i <T p -δT) and pyrolysis layer particle units b i P T p It is the pyrolysis initiation temperature of the material, T p ±δT is the temperature range of the pyrolysis zone. In this embodiment, T p =723K, δT=293K.

[0065] Based on the principle of energy conservation, Fourier thermal conductivity differential equations are established for the particle units of the carbonized layer, intact layer, and pyrolysis layer respectively:

[0066]

[0067]

[0068]

[0069] Where n is the direction vector of the line connecting the centers of the contacting particle units. c is the thermal conductivity of each particle unit layer, a function of temperature. pg It is the isobaric specific heat capacity of the pyrolysis gas. H is the mass flow rate of the pyrolysis gas, ρ is the density of the material in each layer, and H is the mass flow rate of the pyrolysis gas. p This is the heat of phase transition in the pyrolysis reaction. The pyrolysis reaction rate is described by the Arrhenius equation, taking the first-order reaction rate. E is the activation energy of the pyrolysis reaction, and T is the phase transition heat. a It is the starting temperature of the pyrolysis reaction, and Z is the pre-exponential coefficient of the pyrolysis reaction.

[0070] In this embodiment, the outermost particle unit is subject to a second type of boundary condition, while the remaining boundary particle units are subject to adiabatic boundary conditions. The thermal conductivity differential equation for the second type of boundary condition is:

[0071]

[0072] Where, q r (t) is the heat flux density-time curve loaded on the outermost particle unit, α c It is the absorptivity of the carbonized layer, ε w T is the total radiation coefficient of the surface particle unit, σ is the Stepan Boltzmann constant, and T is the total radiation coefficient of the surface particle unit. w It is the temperature of the surface particle unit. It is the oxidation reaction rate on the surface of the carbonized layer, H c It is the heat of combustion of the carbonized layer.

[0073] At each calculation time step, the temperature of all particle elements can be obtained by simultaneously solving the differential equations (7) to (10) for all particle elements. After multiple calculation time steps, the process of thermal diffusion of ablation material caused by boundary heat flow and the process of pyrolysis layer moving from the outside to the inside can be observed.

[0074] Based on the current temperature of the particle unit, the diameter d(T) of the particle unit is calculated, thereby simulating the thermal expansion process of the particle unit:

[0075] d(T)=d0(1+α T ΔT) (11)

[0076] Where d0 is the initial particle diameter, α T ε is the coefficient of thermal expansion of the particles, which is the same as that of the ablation material. ΔT is the temperature change of the particles at the current time step. The overall motion of all particle units in a certain direction due to the temperature change forms the thermal strain ε of the ablation material in that direction, such as... Figure 3 As shown.

[0077] Based on the current porosity Ф and pore pressure p of the discrete system Ф Calculate the diameter d(p) of the particle unit. Ф This simulates the carbon deposition process of particle units.

[0078] d(p Φ )=d0(1+f(p Φ (12)

[0079] Based on literature data, the pore pressure p under specific boundary heat flux conditions was obtained through data fitting. Ф The p-Ф-T curves show the changes in porosity Ф and temperature T. In this embodiment, the macroscopic flow rate of the pyrolysis gas within the pores of the carbonized layer is on the order of mm to cm, with a relative pressure of 1 kPa to 100 kPa. The pore pressure p... Ф With particle diameter d(p) Ф This correlation allows for iterative updates of the particle's surface pressure and diameter, such as... Figure 4 As shown.

[0080] S4 calculates the displacement and angular displacement of the particle unit by integrating the momentum conservation equation twice; updates the velocity, displacement, and diameter of each particle unit, and updates the porosity and pore pressure of the discrete system.

[0081] S5 iterates through the solution and visualization until a specific condition is met, at which point the simulation ends.

[0082] Specifically, the iterative solution steps include:

[0083] a) Retrieve all contact pairs in the computational domain based on the position and diameter of the particle unit at the current time step;

[0084] b) Update the contact area, contact force, and connection force of the particle unit according to formulas (2) to (6);

[0085] c) Update the temperature of the particle unit according to formulas (7) to (10);

[0086] d) Calculate the displacement and angular displacement of the particle unit by integrating the momentum conservation equation twice; calculate the diameter of the particle unit according to formulas (11) and (12); calculate the porosity of the discrete system according to formula (1); and calculate the pore pressure of the discrete system according to the p-Ф-T curve.

[0087] e) Update the visualization scene of the computational domain. In this embodiment, the OpenGL graphics development library is used to render and refresh the visualization scene of the computational domain of the two-dimensional discrete element method. The frequency is refreshed once every 20 computation time steps, so as to observe the processes such as high temperature diffusion of particle units, structural evolution and stress change of particle units in the entire computational domain.

[0088] The numerical simulation process will end if the following specific conditions are met:

[0089] a) The given second type of boundary conditions have been loaded;

[0090] b) The set number of calculation steps is reached;

[0091] c) The particle temperature exceeds the allowable temperature value (1073K).

[0092] Based on the same inventive concept, one embodiment of the present invention provides a bulk ablation simulation program 100 for short fiber reinforced ablation materials, such as... Figure 5 As shown, the program includes:

[0093] The geometric modeling module 110 is used to construct discrete systems in the computational domain, specifying matrix material phase particle units and short fiber phase particle units;

[0094] Mechanical modeling module 120 is used to establish connection units between particle units of the same phase and different phases;

[0095] The mechanical calculation module 130 is used for contact detection and to calculate the forces acting on the particle units.

[0096] Ablation calculation module 140 is used to calculate the temperature of the particle unit;

[0097] The motion update module 150 is used to calculate the position and diameter of particle units; and the porosity and pore pressure of the discrete system.

[0098] The visualization module 160 is used to refresh and display the visualization scene of the computing domain.

[0099] Based on the same inventive concept, another embodiment of the present invention provides a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the volume ablation simulation method for short fiber reinforced ablation materials as described in any of the above embodiments of the present invention.

[0100] Based on the same inventive concept, another embodiment of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When executed by the processor, the program implements the steps in the volume ablation simulation method for short fiber reinforced ablation materials described in any of the above embodiments of this application.

[0101] As the program implementation is basically similar to the method implementation, it is described in a relatively simple way. For relevant details, please refer to the description of the method implementation.

[0102] This application provides a computer-readable storage medium storing computer instructions that, when executed on a computer, cause the computer to perform... Figure 1 The method described.

[0103] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0104] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0105] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0106] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0107] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0108] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

[0109] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for simulating the bulk ablation of short fiber reinforced ablation materials, characterized in that, include: S1, using the discrete element method to construct short fiber reinforced ablation material into a discrete system composed of a series of spherical particle units; S2, at each calculation time step, the contact area, contact force and bonding force of the particle element are calculated using the Hertz-Mindlin contact model and the parallel-bond model; S3 calculates the temperature of the particle unit using the principle of energy conservation and Fourier's law of thermal conductivity; S4, by integrating the momentum conservation equation twice consecutively, calculate the displacement and angular displacement of the particle element; Update the velocity, displacement, and diameter of each particle unit, and update the porosity and pore pressure of the discrete system; S5, iterative solution and visualization, until the simulation ends when a specific condition is met; S3 includes: At each calculation time step, particle element b i Based on temperature, it is divided into carbonized layer particle units b i C , intact layer particle unit b i V and pyrolysis layer particle unit b i P Fourier thermal conductivity differential equations are established for the three types of particle units, and the temperature of each particle unit is solved under given initial conditions and second-type boundary conditions. In S4, the linear change of particle unit diameter with temperature at the microscopic level is used to describe the thermal expansion of the material at the macroscopic level, and the linear change of particle unit diameter with pore pressure at the microscopic level is used to describe the carbon deposition of the material at the macroscopic level. In S5, the specific conditions include: the given second type of boundary conditions have been loaded, the set number of calculation steps has been reached, and the particle temperature exceeds the allowable temperature value.

2. The method for simulating the bulk ablation of a short fiber reinforced ablation material according to claim 1, characterized in that, S1 includes: Using N randomly arranged spherical particle units b i m The matrix material phase of the short fiber reinforced ablation material is represented by M clustered spherical particle units b. i f Representing the short fiber phase, N+M particle units are closely arranged in the computational domain to construct a discrete system that characterizes the porous and heterogeneous structural features of ablation materials.

3. The method for simulating the bulk ablation of a short fiber reinforced ablation material according to claim 1, characterized in that, S2 includes: At each calculation time step, the Hertz-Mindlin contact model was used to calculate the value of each particle element b. i The contact area and contact force at the contact point are determined using the parallel-bond model in particle element b. i m Between, b i f Between, and b i m and b i f Connecting units are established between particles, and the connecting force at each connection is calculated. Once particles come into contact, a contact force is generated. Once a connecting unit breaks, it will not reconnect or generate a connecting force.

4. The method for simulating the bulk ablation of a short fiber reinforced ablation material according to claim 1, characterized in that, In S5, the iterative solution steps include: a) Retrieve all contact pairs in the computational domain based on the position and diameter of the particle unit at the current time step; b) Update the contact area, contact force, and connection force of the particle unit; c) Update the temperature of the particle unit; d) Update the displacement and angular displacement of the particle units; update the velocity, displacement, and diameter of each particle unit; update the porosity and pore pressure of the discrete system; e) Update the visualization of the computing domain.

5. A volume ablation simulation system for short fiber reinforced ablation materials, characterized in that, include: The geometric modeling module is used to construct discrete systems in the computational domain, specifying matrix material phase particle units and short fiber phase particle units; The mechanical modeling module is used to establish connection units between particle units of the same phase and different phases; The mechanical calculation module is used to calculate the contact area, contact force, and bonding force of particle elements using the Hertz-Mindlin contact model and the parallel-bond model at each calculation time step. The ablation calculation module is used to calculate the temperature of the particle unit using the principles of energy conservation and Fourier's law of thermal conductivity; at each calculation step, the particle unit b... i Based on temperature, it is divided into carbonized layer particle units b i C , intact layer particle unit b i V and pyrolysis layer particle unit b i P Fourier thermal conductivity differential equations are established for the three types of particle units, and the temperature of each particle unit is solved under given initial conditions and second-type boundary conditions. The motion update module is used to calculate the displacement and angular displacement of the particle element by integrating the momentum conservation equation twice in succession. Update the velocity, displacement, and diameter of each particle unit, and update the porosity and pore pressure of the discrete system; use the linear change of particle unit diameter with temperature at the microscopic level to describe the thermal expansion of the material at the macroscopic level, and use the linear change of particle unit diameter with pore pressure at the microscopic level to describe the carbon deposition of the material at the macroscopic level. The visualization module is used for iterative solution and visualization until specific conditions are met to end the simulation. These specific conditions include: the given second type of boundary conditions have been loaded, the set number of calculation steps has been reached, and the particle temperature exceeds the allowable temperature value.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 4.

7. A volume ablation simulation device for short fiber reinforced ablation materials, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 4.

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