Method and system for determining interface state of large deformation and moisture loss damage of solid propellant
By establishing a propellant mesoscopic numerical simulation model in ABAQUS and determining the interface state using the energy balance principle, the problems of low applicability and accuracy of existing interface models under large deformations are solved, and accurate prediction of the mechanical response of high solid content propellants under large deformations is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING INST OF TECH
- Filing Date
- 2024-04-19
- Publication Date
- 2026-07-24
AI Technical Summary
Existing interface models are mainly applicable to small deformation conditions and cannot accurately describe the damage evolution of propellants under large deformation. Furthermore, the interface model parameters are difficult to determine, resulting in low applicability and prediction accuracy in propellant formulation design and mechanical performance tuning studies.
A propellant mesoscopic numerical simulation model was established in ABAQUS using Python. An interface geometric model was established by coupling reference points. The damage initiation fracture energy and failure fracture energy were input to determine the interface stress components and current fracture energy. The interface state was determined based on the damage variables. The interface failure condition was derived by combining the energy balance principle, and a new interface model was established.
It improves the applicability and prediction accuracy of propellants under large deformation, and can accurately describe the influence of interfacial mechanical properties on microscopic damage evolution and macroscopic mechanical properties, and is suitable for high solid content and large deformation conditions.
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Figure CN118298976B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of material interface state determination technology, and in particular to a method and system for determining the interface state of solid propellant under large deformation and dehydration damage. Background Technology
[0002] Because the modulus of propellant filler particles is 3-5 orders of magnitude larger than that of the matrix, there is a severe mismatch in stiffness, and a distinct interface exists, exhibiting non-uniformity in the microstructure. This leads to the macroscopic mechanical behavior being strongly dependent on the microstructural characteristics. The interface, as one of the weakest links, is crucial for accurately describing the mechanical behavior of propellants. However, the current lack of suitable interface mechanical models has resulted in unclear damage evolution mechanisms and influencing factors under large deformations, severely limiting propellant formulation design and mechanical performance tuning research. Existing interface models mainly include the cohesive zone model (CMZ), which is primarily used for small deformations in materials such as concrete, metals, and explosives. However, since propellants typically undergo large deformations, the cost of accurately describing propellant damage evolution is becoming increasingly high, posing a significant challenge to existing technologies and methods. Therefore, new interface models suitable for large deformations have emerged.
[0003] Describing the mechanical behavior of material interfaces typically involves establishing an interface model and determining its parameters. Currently, the cohesive force model is used to describe the mechanical behavior of interfaces.
[0004] (1) Cohesion Model. This is typically represented by a load-displacement relationship. Common models include bilinear and exponential types, such as... Figure 1 As shown. This mainly includes damage initiation criteria, damage evolution, and failure criteria. For example, the bilinear cohesion model (such as...) Figure 1 The law of traction force-displacement in the normal direction (or tangential direction in the s and t directions) of -f)n satisfies:
[0005]
[0006] The interface damage factor D is:
[0007]
[0008] In equations (1.1) to (1.2): <·> = (·+|·|) / 2, which means that damage is not considered when the phase interface is in a compressed state. (T) n ,T t ,T s ), (δ n ,δ t ,δ s ) represent the traction force T component and displacement δ component of the cohesive unit, respectively; δ0, δ fThe curve represents the damage initiation displacement and failure displacement; the area enclosed by the curve is the interfacial fracture energy Γ. coh .
[0009] Interface damage initiation criteria include stress failure criteria, maximum strain failure criteria, and mixed failure criteria. A typical secondary stress failure criterion is shown in equation (3), which means that when the sum of the squares of the ratios of the tensile and shear stresses (in both directions) on the phase interface to its maximum allowable stress equals 1, the phase interface begins to enter the irreversible damage stage, i.e., the damage factor in equation (2) is non-zero.
[0010]
[0011] (2) Determination of cohesive model parameters. Experimentally, Raman spectroscopy was used to measure the interface parameters of individual particles. However, Raman spectroscopy can only determine the changes in the stress distribution field around the interface; when microcracks propagate to the interface can only be determined using microscopy. This places high demands on the coordination between the two types of equipment, and the test results are highly random and susceptible to human influence, requiring extremely high resolution of the loading equipment. In numerical simulation, interface parameters were mainly determined by inversion. However, since the macroscopic stress and strain of the propellant are determined by the matrix, particles, interface, and their coupling effects, the results obtained from inversion have many possibilities (results from different literatures vary considerably).
[0012] Propellant interface models typically employ cohesive force models. Hou Yufei, Feng Tao, and others have studied the influence of propellant interface mechanical properties on propellant mechanical properties based on cohesive force element models, but the strain is only around 0.2. Figure 2 As shown, there is a significant difference between the actual large deformation of the propellant and that of the real propellant. Han Long et al. used a cohesive force model to study the mechanical response of NEPE propellant and found that the interface parameters determine its dewetting failure process under load.
[0013] Yang et al. used a cohesive force model to study the mechanical properties and microscopic damage evolution of propellants with different solid contents at different strain rates and temperatures, such as... Figure 3 As shown, although the particle content is high, the deformation is small, and it is not yet possible to represent the actual propellant damage process.
[0014] Zhi Shijun et al. used the cohesive force model to study the influence of dewetting on the main macroscopic mechanical parameters of propellants and proposed a method for determining the interface microscopic parameters based on inversion. However, due to the large number of factors affecting the macroscopic mechanical properties of propellants, the reliability of the obtained interface parameters still needs to be discussed.
[0015] Zhang Chao established a three-dimensional microscopic model, such as Figure 4As shown, although the particle content differs from that of the real material, it can still indicate the location of stress concentration. However, due to the presence of the interface, it can only predict the average mechanical properties of the material in the linear elastic stage, and the strain is relatively small (~10%), which is much smaller than the deformation strain of the real propellant.
[0016] Xia Quanzhi, Wu et al. used a cohesive force model to study the mechanical properties of PBX. The interface model parameters were determined through numerical inversion or empirical methods, such as... Figure 5 As shown, although the PBX particle content is high, its deformation is very small (strain is about 3%), which is significantly different from the strain of 100% propellant.
[0017] Current cohesive interface models are only suitable for small deformation ranges (<35%) or models with low filler volume fractions, and cannot reflect the actual deformation (e.g., strain greater than 100%) and damage evolution of real propellants. Figure 6 As shown.
[0018] Existing cohesive interface models are only applicable to the damage evolution and macroscopic mechanical properties of propellants under small deformations. These models can be used for materials with high solids content but small deformations (e.g., PBX: solids content 0.95%, strain 5%), and the calculated strain is even smaller in three dimensions; or for materials with low solids content but large deformations (e.g., filled rubber: solids content 0.1%, strain 80%). However, both differ significantly from real propellants. Furthermore, determining the parameters of the cohesive model is very difficult, and the parameters obtained using different numerical inversion methods vary greatly. In summary, existing interface models have two main problems: first, they are not suitable for large propellant deformations, making practical application difficult; second, the interface models are difficult to determine, highly variable, and have low accuracy, resulting in poor applicability to propellants and low prediction accuracy. Summary of the Invention
[0019] This invention provides a method and system for determining the interface state of large deformation and dehydration damage in solid propellants, which can improve the applicability and prediction accuracy of propellants.
[0020] To achieve the above objectives, the present invention provides the following solution:
[0021] A method for determining the interface state of large deformation and dehydration damage in solid propellants includes:
[0022] A propellant mesoscopic numerical simulation model was established using Python in ABAQUS.
[0023] The propellant mesoscopic numerical simulation model is coupled with a reference point to establish an interface geometric model;
[0024] Input the damage initiation fracture energy and failure fracture energy between the particles and the binder;
[0025] Based on the invoked functional program, the interface stress components of the interface geometric model are determined;
[0026] The current fracture energy is determined based on the interface stress components.
[0027] Based on the damage initiation fracture energy, failure fracture energy, and current fracture energy, the damage variables are determined;
[0028] The interface state is determined based on the damage variables.
[0029] Optionally, it also includes:
[0030] Extract the force and displacement of the reference point;
[0031] Calculate stress and strain based on the force, displacement, and action-reaction relationship.
[0032] Optionally, determining the interface stress components of the interface geometric model based on the invocation of the functional program specifically includes:
[0033] The functional program getvrm is called to read the stress components σ respectively. 11 σ 22 σ 33 σ 12 σ 13 and σ 23 ;
[0034] According to formula S ij =σ ij -σ ii / 3, Calculate the interface stress components S ij .
[0035] Optionally, determining the damage variable based on the damage initiation fracture energy, failure fracture energy, and current fracture energy specifically includes:
[0036] Based on the damage initiation fracture energy, failure fracture energy, and current fracture energy, the formula is used. Identify damage variables;
[0037] Where γ0 is the damage initiation fracture energy, γ f γ represents the failure fracture energy, and γ represents the current fracture energy.
[0038] Optionally, determining the interface state based on the damage variable specifically includes:
[0039] If the damage variable D new A value of 0 indicates that the interface is completely disabled.
[0040] If the damage variable D newA value of 1 indicates that the interface has undergone elastic changes;
[0041] If the damage variable D new A value between 0 and 1 indicates that the interface is damaged but has not yet failed.
[0042] A system for determining the interface state of large deformation and dehydration damage in solid propellants includes:
[0043] The module for establishing a propellant micro-numerical simulation model is used to establish a propellant micro-numerical simulation model in ABAQUS using the Python language.
[0044] The interface geometry model establishment module is used to couple the propellant microscopic numerical simulation model with a reference point to establish an interface geometry model.
[0045] Damage initiation fracture energy and failure fracture energy input module, used to input the damage initiation fracture energy and failure fracture energy between particles and adhesive;
[0046] The interface stress component determination module is used to determine the interface stress components of the interface geometric model based on the invocation of functional programs.
[0047] The current fracture energy determination module is used to determine the current fracture energy based on the interface stress components.
[0048] The damage variable determination module is used to determine damage variables based on the damage initiation fracture energy, failure fracture energy, and current fracture energy.
[0049] The interface state determination module is used to determine the interface state based on the damage variables.
[0050] An electronic device includes a memory and a processor, the memory storing a computer program and the processor running the computer program to enable the electronic device to perform a method for calibrating microscopic damage parameters of solid propellants.
[0051] A computer-readable storage medium stores a computer program that, when executed by a processor, implements a method for calibrating microscopic damage parameters of solid propellants.
[0052] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:
[0053] This invention provides a method for determining the interface state of large deformation and dewetting damage in solid propellants. The method includes: establishing a propellant mesoscopic numerical simulation model using Python in ABAQUS; coupling the propellant mesoscopic numerical simulation model with a reference point to establish an interface geometric model; inputting the damage initiation fracture energy and failure fracture energy between particles and the binder; determining the interface stress components of the interface geometric model by calling a functional program; determining the current fracture energy based on the interface stress components; determining damage variables based on the damage initiation fracture energy, failure fracture energy, and current fracture energy; and determining the interface state based on the damage variables. Using this invention can improve the applicability of propellants and the accuracy of prediction. Attached Figure Description
[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0055] Figure 1 This is a schematic diagram of the interface traction force-displacement relationship;
[0056] Figure 2 A schematic diagram of phase interface damage evolution based on a two-dimensional microscopic model of propellant;
[0057] Figure 3 Numerical simulation results for the microscopic model of particulate filler materials;
[0058] Figure 4 For three-dimensional microscopic simulation based on real structures;
[0059] Figure 5 A schematic diagram illustrating the study of PBX mechanical behavior using cohesive elements;
[0060] Figure 6 To observe the relationship between simulated particle content and maximum strain in detail;
[0061] Figure 7 This is a schematic diagram illustrating the energy relationships and damage evolution during the deformation process;
[0062] Figure 8 This is a flowchart of the method for determining the interface state of solid propellant under large deformation and dehydration damage according to the present invention.
[0063] Figure 9 To visualize the geometric model in numerical simulation;
[0064] Figure 10 An interface unit is embedded on the common edge of the adhesive matrix and particles;
[0065] Figure 11 Input the material model and parameters;
[0066] Figure 12 A structural diagram of the system for determining the interface state of large deformation and dewetting damage of solid propellants in this invention;
[0067] Figure 13 Predictive capabilities for microstructure and interface models with a particle volume fraction of 60%;
[0068] Figure 14 This is a schematic diagram of the microscopic damage evolution of the propellant under large deformation conditions.
[0069] Figure 15 It has the ability to predict three-dimensional microstructure and interface models with a particle volume fraction of 60%. Detailed Implementation
[0070] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0071] This invention provides a method and system for determining the interface state of large deformation and dehydration damage in solid propellants, which can improve the applicability and prediction accuracy of propellants.
[0072] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0073] The following explains the technical fields involved in this invention:
[0074] Solid propellant: A filled composite material with a polymer binder as the matrix (continuous phase) and solid oxidants and metallic fuels as fillers (dispersed phase), with a solid content as high as ~88%.
[0075] Large deformation: The change in volume or shape of a material under external load, and the finite deformation is nonlinear, usually exceeding the linear elastic stage (generally strain greater than 10%) and accompanied by non-negligible rotation.
[0076] Interfacial dehydration: During the preparation process, the propellant matrix and particles are bonded together through chemical reactions and physical adsorption to form an interface with a certain strength. However, when external conditions change, the matrix and particles will separate, which is called "interfacial dehydration".
[0077] Interface model: describes the interface between the propellant matrix and the particles, and uses a certain mathematical model to describe its mechanical properties.
[0078] Solid propellants are high-solids-content particle-filled composite materials, with a distinct interface between the matrix and the particles. Experiments and theory show that the interface is one of the weakest links in the propellant, significantly impacting its mechanical properties. To understand the influence of the interface on propellant mechanical properties and formulation design, cohesive models are typically used to describe its interfacial mechanical behavior. However, existing interface models are only applicable to propellants with relatively low solids content (<0.3%) or small deformations (e.g., strain 1%–12%), suffer from low computational efficiency, and have large deviations in predicting failure paths, showing significant differences from real propellants with high solids content (>0.6%) and large strains (~100%). Furthermore, determining the parameters of cohesive models is difficult, and their convergence is poor. To overcome these shortcomings, this invention proposes a method for determining the interface state of large deformation dewetting damage in solid propellants. This method is applicable to high-solids-content and large-deformation propellants and can reveal the influence of interfacial mechanical properties on microscopic damage evolution and macroscopic mechanical properties. The basis of this invention lies in linking interface mechanical parameters to fracture energy. Determining interface model parameters is simple, easy, and more practical. Furthermore, this invention establishes a criterion for the initiation and evolution of interface damage, enabling accurate prediction of the mechanical response of propellants under various complex load conditions.
[0079] This invention derives the interface failure conditions based on the energy balance principle during deformation. Figure 7 This is a schematic diagram of the energy relationships and damage evolution during the deformation process.
[0080] Depend on Figure 7 It can be seen that the deformation energy can be decomposed into elasticity (W) ee ), dissipation (W) diss ) and dehumidification (W deb Required energy:
[0081] δW ex =δW ee +δW diss +δW deb (4)
[0082] For W ex W ee Decompose:
[0083]
[0084]
[0085] In the formula S ij For deviatoric stress, σ ii =σ 11 +σ 22 +σ33 For hydrostatic pressure; e ij For partial strain, e = e 11 +e 22 +e 33 G0 represents volumetric strain; G0 and K0 represent shear modulus and bulk modulus, respectively.
[0086] Due to the viscoelastic properties of propellants, their modulus is time-dependent and is generally expressed as a k-th order Prony series.
[0087]
[0088] In the formula
[0089] To simplify the analysis, assuming that the propellant bulk modulus and shear modulus have the same form, the above equation can be dimensionless:
[0090]
[0091] In the formula m k =G k / G0=K k / K0,m ∞ =G ∞ / G0=K ∞ / K0.
[0092] Substituting equation (8) into equation (5), we get:
[0093]
[0094] In the formula e ij k e k This represents the strain deviation and volume component corresponding to the k-th Prony series.
[0095] By combining equations (5) to (8), we can obtain:
[0096]
[0097] When dehydration occurs on surface δA, equation (10) will become:
[0098]
[0099] In the formula γ f V0 represents the failure fracture energy between the particles and the adhesive, which can be approximated by the adhesion work; V0 is the unit volume.
[0100] For propellants, which are nearly incompressible materials, their bulk modulus is several orders of magnitude larger than their shear modulus (10^6). 2 ~10 4 Therefore, before dehumidification occurs... The value is close to zero; furthermore, dehydration is generally not considered to occur in the compression direction, as described by equation (1), that is, dehydration does not easily occur under three-dimensional compressive stress. With the above assumptions, equation (11) can be transformed into:
[0101]
[0102] In the formula, α is a constant.
[0103] Damage parameters are defined based on the cohesive force model:
[0104]
[0105] In the formula, γ0 is the damage initiation fracture energy, which can generally be taken as γ0. Alternatively, you can enter a specific value, representing that the interface does not suffer damage in Stage-I; and the interface completely fails in Stage-III, such as... Figure 7 As shown in equation (12), the new interface damage proposed in this invention is related to the fracture energy and stress state. The fracture energy can be easily calculated by testing the contact angle.
[0106] In fact, equations (12)-(13) define the damage initiation conditions and evolution rules of the new interface model, which can be used in conjunction with any conventional elastic or hyperelastic model. If the simplest linear elastic model is adopted, the constitutive model of the new interface can be expressed as:
[0107] T int =(1-D new )Eε int (14)
[0108] In the formula T int ε int These represent the interfacial stress and strain, respectively; E is the elastic modulus, using the same value as the matrix. Therefore, only D needs to be known. new This allows us to determine the stress state under arbitrary interface deformation, while D new It can be determined according to equations (12)-(13).
[0109] Typically, this interface model is used in conjunction with mesoscopic numerical simulation. The method for establishing the mesoscopic model is mature and will not be described in detail here, but will be explained in detail in the steps of the implementation example.
[0110] Example 1:
[0111] Figure 8 The flowchart of the method for determining the interface state of large deformation and dewetting damage of solid propellants according to the present invention is as follows: Figure 8 As shown, a method for determining the interface state of solid propellant under large deformation and dehydration damage includes:
[0112] Step 101: Use Python to establish a propellant micro-numerical simulation model in ABAQUS.
[0113] A propellant mesoscopic numerical simulation model is generated in ABAQUS using Python. Given the mesoscopic model dimensions, particle content, particle size, particle shape, and mesh size, etc. Figure 8 As shown. This process can be completed using publicly available scripts or software, including but not limited to "Simulation Software for Dehumidification of Composite Solid Propellant Phase Interface V1.0:2023SR0802872".
[0114] Step 102: Couple the propellant mesoscopic numerical simulation model with the reference point to establish an interface geometric model.
[0115] A reference point is established in ABAQUS and coupled with the mesoscopic model. Then, loads are applied to the reference point to establish the interface geometry model.
[0116] Interface units are embedded on the common edge of the adhesive matrix and particles using a Python script, such as... Figure 10 As shown. This process can be completed using publicly available scripts or software, including but not limited to "Simulation Software for Dehumidification of Composite Solid Propellant Phase Interface V1.0:2023SR0802872".
[0117] Step 103: Input the damage initiation fracture energy and failure fracture energy between the particles and the adhesive.
[0118] In the ABAQUS material library, both the adhesive matrix and particles are selected as linear elastic models. The elastic modulus E and Poisson's ratio υ are input respectively. Figure 11 As shown.
[0119] This step also includes:
[0120] In the ABAQUS material library, select User-Defined Material (UMAT), and enter the elastic modulus E, Poisson's ratio υ, interface damage initiation fracture energy γ0, and failure fracture energy γ in the material parameter list. f ,like Figure 11 As shown.
[0121] Step 104: Determine the interface stress components of the interface geometric model according to the invoked functional program.
[0122] This step specifically includes:
[0123] The functional program getvrm is called to read the stress components σ respectively. 11 σ 22 σ 33 σ 12 σ 13 and σ23 ;
[0124] According to formula S ij =σ ij -σ ii / 3, Calculate the interface stress components S ij .
[0125] Step 105: Determine the current fracture energy based on the interface stress components.
[0126] The formula is used based on the interface stress components. Determine the current fracture energy.
[0127] Step 106: Determine the damage variables based on the damage initiation fracture energy, failure fracture energy, and current fracture energy.
[0128] This step specifically includes:
[0129] Based on the damage initiation fracture energy, failure fracture energy, and current fracture energy, the formula is used. Identify damage variables;
[0130] Where γ0 is the damage initiation fracture energy, γ f γ represents the failure fracture energy, and γ represents the current fracture energy.
[0131] Step 107: Determine the interface state based on the damage variables.
[0132] This step specifically includes:
[0133] If the damage variable D new A value of 0 indicates that the interface is completely disabled.
[0134] If the damage variable D new A value of 1 indicates that the interface has undergone elastic changes;
[0135] If the damage variable D new A value between 0 and 1 indicates that the interface is damaged but has not yet failed.
[0136] The method for determining the interface state of large deformation and dewetting damage in solid propellants according to the present invention further includes:
[0137] Step 108: Extract the force and displacement of the reference point;
[0138] Step 109: Calculate stress and strain based on the force, displacement, and action-reaction relationship.
[0139] Furthermore, the stress σ is calculated based on the action-reaction relationship. R and strain ε R , specifically:
[0140]
[0141] In the formula, A0 and l0 are the initial area and length of the microscopic model, respectively.
[0142] This invention proposes a method for determining the interface state of dehydration damage in solid propellants under large deformation, applicable to propellants with high solid content and large deformation. It reveals the influence of interface mechanical properties on microscopic damage evolution and macroscopic mechanical properties. The basis of this invention lies in linking interface mechanical parameters to fracture energy, making the determination of interface model parameters simpler, easier, and more practical. Furthermore, this invention establishes criteria for interface damage initiation and evolution, enabling accurate prediction of the mechanical response of propellants under various complex load conditions.
[0143] Example 2:
[0144] Figure 12 The system structure diagram for determining the interface state of large deformation and dewetting damage of solid propellants in this invention is shown below. Figure 12 As shown, a system for determining the interface state of solid propellant under large deformation and dehydration damage includes:
[0145] The propellant micro-numerical simulation model establishment module 201 is used to establish a propellant micro-numerical simulation model in ABAQUS using the Python language.
[0146] Interface geometry model establishment module 202 is used to couple the propellant microscopic numerical simulation model with the reference point to establish an interface geometry model;
[0147] Damage initiation fracture energy and failure fracture energy input module 203 is used to input the damage initiation fracture energy and failure fracture energy between particles and adhesive;
[0148] Interface stress component determination module 204 is used to determine the interface stress components of the interface geometric model according to the called functional program;
[0149] The current fracture energy determination module 205 is used to determine the current fracture energy based on the interface stress components.
[0150] The damage variable determination module 206 is used to determine damage variables based on the damage initiation fracture energy, failure fracture energy and current fracture energy;
[0151] The interface state determination module 207 is used to determine the interface state based on the damage variables.
[0152] Example 3:
[0153] This embodiment provides an electronic device, including a memory and a processor. The memory stores a computer program, and the processor runs the computer program to enable the electronic device to execute the interface state determination method for large deformation and dehydration damage of solid propellants according to Embodiment 1.
[0154] Alternatively, the aforementioned electronic device may be a server.
[0155] In addition, embodiments of the present invention also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the interface state determination method for large deformation and dehydration damage of solid propellants according to Embodiment 1.
[0156] Embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0157] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. 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 illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0158] 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 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0159] 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 1One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0160] Example 4:
[0161] This invention proposes a novel interface model based on the energy balance principle during the deformation process to address the microscopic damage during the large deformation process of propellants. According to... Figure 8 The specific steps described were used to perform microscopic numerical simulations of solid propellants. Figure 13 To demonstrate the predictive capabilities of the mesoscopic and interface models with a particle volume fraction of 60%, the prediction results of the cohesive force model and the novel interface model proposed in this invention under large propellant deformation are presented using the same mesoscopic numerical simulation. Figure 13 It is evident that, under the same particle content (60 vol%), the cohesive model can only calculate strain up to 0.4, while the new interface model proposed in this invention can calculate strain up to 1.1, increasing the calculation range by nearly 200%. This demonstrates that, under large deformation conditions, the new interface model proposed in this invention has better applicability than the cohesive model. Furthermore, under large deformation conditions, the prediction results of the new interface model proposed in this invention for the macroscopic mechanical properties of the propellant are in good agreement with the experimental results, further illustrating the reliability and accuracy of the new interface model proposed in this invention.
[0162] Figure 14 This diagram illustrates the microstructural evolution of propellant under large deformation conditions, showcasing the microstructural evolution of the propellant in a two-dimensional configuration. Figure 13 As can be seen, the novel interface model proposed in this invention has excellent predictive ability under large deformations and a wide range of applications. The microscopic damage prediction results are compared with those obtained using scanning electron microscopy (SEM) after the experiment. Figure 1 This invention overcomes the problem that existing cohesive interface models can only describe the microscopic damage evolution in a dimensional sense, and at the same time realizes the prediction of damage evolution of materials with "high solid content and large deformation".
[0163] Example 5:
[0164] Figure 15 The predictive capabilities of the three-dimensional mesoscopic model and interface model for particles with a volume fraction of 60% are demonstrated, showcasing the application of the novel interface model proposed in this invention in the three-dimensional mesoscopic numerical simulation of propellants. Figure 15It is evident that even under the three-dimensional high solids content (60 vol%) model conditions, the novel interface model proposed in this invention can accurately predict the macroscopic mechanical response of the propellant within a strain of up to 0.8, demonstrating the good applicability of the novel interface model proposed in this invention under large deformation conditions. Furthermore, the numerical simulation damage results are consistent with the in-situ CT scan results obtained by Xing et al., further illustrating the reliability and accuracy of the novel interface model proposed in this invention.
[0165] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.
[0166] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.
Claims
1. A method for determining the interface state of large deformation and dehydration damage in solid propellants, characterized in that, The method for determining the interface state applicable to large deformation and dehydration damage of solid propellants includes: A propellant mesoscopic numerical simulation model was established using Python in ABAQUS. The propellant mesoscopic numerical simulation model is coupled with a reference point to establish an interface geometric model; Input the damage initiation fracture energy and failure fracture energy between the particles and the binder; Based on the invoked functional program, the interface stress components of the interface geometric model are determined; The current fracture energy is determined based on the interface stress components. Based on the damage initiation fracture energy, failure fracture energy, and current fracture energy, the damage variables are determined; The interface state is determined based on the damage variables; The step of determining the interface stress components of the interface geometric model based on the invocation of the functional program specifically includes: The functional program getvrm is called to read the stress components respectively. and ; According to the formula Calculate the interfacial stress components ; The current fracture energy is determined based on the interface stress components, specifically including: The formula is used based on the interface stress components. Determine the current fracture energy; among which, It is a constant; The determination of damage variables based on the damage initiation fracture energy, failure fracture energy, and current fracture energy specifically includes: Based on the damage initiation fracture energy, failure fracture energy, and current fracture energy, the formula is used. Determine the damage variables; in, The damage initiation fracture energy, The failure fracture energy, This represents the current fracture energy.
2. The method for determining the interface state of large deformation and dewetting damage in solid propellants according to claim 1, characterized in that, Also includes: Extract the force and displacement of the reference point; Calculate stress and strain based on the force, displacement, and action-reaction relationship.
3. The method for determining the interface state of large deformation and dewetting damage in solid propellants according to claim 1, characterized in that, Determining the interface state based on the damage variables specifically includes: If the damage variable D new A value of 0 indicates that the interface is completely disabled. If the damage variable D new A value of 1 indicates that the interface has undergone elastic changes; If the damage variable D new A value between 0 and 1 indicates that the interface is damaged but not yet disabled.
4. A system for determining the interface state of large deformation and dehydration damage in solid propellants, characterized in that, The interface state determination system applicable to large deformation and dehydration damage of solid propellants includes: The module for establishing a propellant micro-numerical simulation model is used to establish a propellant micro-numerical simulation model in ABAQUS using the Python language. The interface geometry model establishment module is used to couple the propellant microscopic numerical simulation model with a reference point to establish an interface geometry model. The damage initiation fracture energy and failure fracture energy input module is used by the user to input the damage initiation fracture energy and failure fracture energy between the particles and the adhesive. The interface stress component determination module is used to determine the interface stress components of the interface geometric model based on the invocation of functional programs. The current fracture energy determination module is used to determine the current fracture energy based on the interface stress components. The damage variable determination module is used to determine damage variables based on the damage initiation fracture energy, failure fracture energy, and current fracture energy. The interface state determination module is used to determine the interface state based on the damage variables. The step of determining the interface stress components of the interface geometric model based on the invocation of the functional program specifically includes: The functional program getvrm is called to read the stress components respectively. and ; According to the formula Calculate the interfacial stress components ; The current fracture energy is determined based on the interface stress components, specifically including: The formula is used based on the interface stress components. Determine the current fracture energy; among which, constant It is a constant; The determination of damage variables based on the damage initiation fracture energy, failure fracture energy, and current fracture energy specifically includes: Based on the damage initiation fracture energy, failure fracture energy, and current fracture energy, the formula is used. Determine the damage variables; in, The damage initiation fracture energy, The failure fracture energy, This represents the current fracture energy.
5. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program, and the processor runs the computer program to enable the electronic device to perform the method for determining the interface state of large deformation and dehydration damage of solid propellants as described in any one of claims 1-3.
6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the method for determining the interface state of large deformation and dehydration damage of solid propellants as described in any one of claims 1-3.