Multiscale analysis method and device for high-temperature relaxation behavior of helical spring

Abstract

This invention relates to a multi-scale analysis method and apparatus for the high-temperature relaxation behavior of helical springs, belonging to the field of materials analysis technology. The method includes: based on the geometric parameters and axial compression conditions of the target helical spring, a helical coil segment of a predetermined proportion is selected as the analysis unit; after verification through equivalent boundary conditions and simulation, a simplified micro-coil geometric model is output; using the simplified micro-coil geometric model as the geometric carrier, polycrystalline microstructure parameters are imported to construct a polycrystalline model; meshing is performed and corresponding boundary conditions are applied to obtain a finite element solvable model; constitutive parameters at a set high temperature are assigned based on the thermally activated crystal plastic finite element method, and high-temperature stress relaxation simulation calculations are performed to obtain the relaxation degradation curve of the target helical spring. This invention can provide precise and efficient technical support for the multi-scale analysis and optimization design of the high-temperature relaxation performance of helical springs.

Description

Technical Field

[0001] This invention relates to the field of materials analysis technology, and in particular to a multi-scale analysis method and apparatus for the high-temperature relaxation behavior of helical springs. Background Technology

[0002] Cylindrical helical compression springs are core kinetic energy elastic elements widely used in various separation and release devices. These elastic elements typically remain in a pre-compressed state for extended periods during service, bearing static loads and environmental stresses, and utilize their own rebound force to perform the intended function when action is required. With the increasing integration and complexity of structural systems, higher demands are placed on the performance degradation analysis and lifespan prediction of elastic elements under long-term loads. Therefore, establishing analytical methods capable of supporting the evaluation and optimization of the mechanical properties of elastic elements has become a pressing technical problem to be solved in this field.

[0003] For helical compression springs operating in high-temperature environments, stress relaxation is one of the main forms of performance degradation. Relaxation behavior is closely related to the high-temperature creep mechanism of materials, and the creep performance of materials strongly depends on their microstructure characteristics. Taking TC4 titanium alloy as an example, its microstructure parameters, such as the volume fraction of the α and β phases, grain size, and crystallographic texture orientation, significantly affect the plastic deformation behavior of the material under high temperature and stress, thus determining the evolution path of the macroscopic relaxation performance of the elastic element. Therefore, establishing the ability to analyze the macroscopic relaxation behavior of elastic elements from the microstructure level will help to deeply understand the intrinsic mechanism of performance degradation.

[0004] Among existing methods for analyzing the mechanical properties of structural components, macroscopic finite element simulation can handle the mechanical response of complex geometries under various loads relatively well, but it cannot characterize the influence of microstructure on macroscopic performance. While the microscopic crystal plasticity finite element method can simulate deformation behavior at the grain scale, it is limited by computational scale and is usually only applicable to specimens with simple shapes or representative volume elements, making it difficult to directly apply to engineering structures with complex curved surface geometries, such as helical springs. Existing research has shown that by constructing a representative volume element model and combining it with homogenization methods, the influence of microstructure can be introduced into the macroscopic constitutive model. However, for helical structures where bending-torsional coupled stress is the main form of stress, this approach struggles to accurately describe the local deformation differences caused by the stress gradient within the spring wire cross-section, leading to an oversimplification of the influence of microstructure in macroscopic analysis. Summary of the Invention

[0005] Therefore, it is necessary to address the problem that existing macroscopic analysis methods cannot establish the intrinsic relationship between microstructural characteristics such as grain size, phase ratio, and crystallographic texture orientation and the macroscopic relaxation degradation performance of helical springs under high-temperature long-term pre-tightening service conditions. Furthermore, existing crystal plasticity simulation schemes suffer from contradictions such as excessively high computational costs for full-size models and insufficient stress reproduction of simplified models, making it difficult to support the accurate optimization of the relaxation resistance of elastic elements and the refined design of multiple scales. To address this, a multi-scale analysis method and device for the high-temperature relaxation behavior of helical springs should be provided.

[0006] A multi-scale analysis method for the high-temperature relaxation behavior of helical springs, the method comprising: Based on the geometric parameters and axial compression conditions of the target helical spring, and taking into account the characteristic that the stress is uniformly distributed along the helix under axial compression, a helical coil segment of a preset proportion is selected as the analysis unit. After verification through equivalent boundary conditions and simulation, a simplified micro-coil geometric model consistent with the mechanical response of the complete helical spring is output. Using the simplified microcoil geometric model as the geometric carrier, polycrystalline microstructure parameters are imported to construct a polycrystalline model containing crystallographic features; the polycrystalline model is meshed and corresponding boundary conditions are applied to obtain a finite element solvable model. Based on the thermally activated crystal plastic finite element method, constitutive parameters at a set high temperature are assigned to the finite element solvable model, and high-temperature stress relaxation simulation calculation is performed to obtain stress cloud diagram; Based on the stress cloud diagram, the volume average stress at the corresponding time step is calculated to obtain the relaxation degradation curve of the target helical spring.

[0007] On the other hand, a multi-scale analysis device for the high-temperature relaxation behavior of helical springs is also provided, comprising: The simplified microcoil geometry model construction module is used to select a pre-proportioned segment of the helical coil as the analysis unit based on the geometric parameters and axial compression conditions of the target helical spring and the characteristic that the stress is uniformly distributed along the helix under axial compression. After equivalent boundary conditions and simulation verification, it outputs a simplified microcoil geometry model that is consistent with the mechanical response of the complete helical spring. The finite element solveable model construction module is used to construct a polycrystalline model containing crystallographic features by importing polycrystalline microstructure parameters using the simplified microcoil geometric model as the geometric carrier; meshing the polycrystalline model and applying corresponding boundary conditions to obtain a finite element solveable model. The stress cloud diagram calculation module is used to assign constitutive parameters at a set high temperature to the finite element solvable model based on the thermally activated crystal plastic finite element method, perform high temperature stress relaxation simulation calculation, and obtain stress cloud diagram; The relaxation degradation curve calculation module is used to calculate the volume average stress at the corresponding time step based on the stress cloud diagram, and obtain the relaxation degradation curve of the target helical spring.

[0008] Compared with existing technologies, the multi-scale analysis method and apparatus for high-temperature relaxation behavior of helical springs provided by this invention have the following advantages: 1. Based on the characteristic that the stress is uniformly distributed along the helix under axial compression, a coil segment is cut off. A simplified micro-coil model is obtained through equivalent boundary condition matching and simulation verification. While ensuring a high degree of consistency with the mechanical response of the complete helical spring, the simulation calculation scale is reduced, effectively balancing the analysis accuracy and calculation cost, and solving the problems of excessive calculation volume of the full-size model and insufficient force reproduction of the simplified model.

[0009] 2. A polycrystalline model containing crystallographic features is constructed using an equivalent simplified microcoil as the geometric carrier, which opens up the correlation path between microstructure features and macroscopic relaxation performance of helical springs. This breaks through the limitation of traditional macroscopic simulation that cannot characterize the influence of microstructure on degradation behavior, and enables quantitative analysis of the influence of microstructure parameters on relaxation performance.

[0010] 3. High-temperature stress relaxation simulation is carried out using the thermally activated crystal plastic finite element method. The relaxation degradation curve is obtained by combining the volume average stress calculation. This method can accurately reproduce the stress relaxation evolution process of the helical spring under high-temperature preload conditions, and can provide reliable technical support for the evaluation of the high-temperature relaxation performance of the helical spring, the optimization of relaxation resistance, and the multi-scale refined design. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention, and those skilled in the art can obtain other related drawings based on these drawings without creative effort.

[0012] Figure 1 This is a flowchart illustrating a multi-scale analysis method for the high-temperature relaxation behavior of a helical spring in one embodiment. Figure 2 This is a schematic diagram of the geometry of the target helical spring in one embodiment; Figure 3 This is a simplified geometric model diagram of a microcoil in one embodiment; Figure 4 This is a schematic diagram illustrating static simulation verification in one embodiment, wherein, Figure 4 (a) is the static simulation stress cloud diagram of the target helical spring. Figure 4 (b) Stress cloud diagram of static simulation to simplify the geometric model of the microcoil; Figure 5This is a schematic diagram illustrating the consistency simulation verification of the relaxation mechanical response of a simplified microcoil geometry model from 0 to 1000 s in one embodiment. Figure 5 (a) is the stress cloud diagram of the relaxation degradation simulation at 50 s; Figure 5 (b) is the stress cloud diagram of the relaxation degradation simulation after 200 s; Figure 5 (c) is the stress cloud diagram of the relaxation degradation simulation at 1000s; Figure 5 (d) is a schematic diagram of the normalized relaxation degradation curve; Figure 6 This is a polycrystalline model diagram containing different microstructure features in one embodiment, wherein, Figure 6 (a) is a polycrystalline model diagram of the first type of microstructure characteristics. Figure 6 (b) is a polycrystalline model diagram of the second type of microstructure. Figure 6 (c) is a polycrystalline model diagram of the third type of microstructure; Figure 7 This is a schematic diagram of mesh generation and boundary condition settings for a polycrystalline model in one embodiment; Figure 8 This is a schematic diagram illustrating the relaxation degradation simulation of a finite element solveable model with different grain sizes in one embodiment. Figure 8 (a) is a simulation stress cloud diagram of relaxation degradation for 50 grains; Figure 8 (b) is a simulation stress cloud diagram of relaxation degradation for 100 grains; Figure 8 (c) is a simulation stress cloud diagram of relaxation degradation for 300 grains; Figure 9 This is a schematic diagram of the normalized relaxation degradation curves of the finite element solveable model for different grain sizes corresponding to the target helical spring in one embodiment. Figure 10 This is a structural block diagram of a multi-scale analysis device for the high-temperature relaxation behavior of a helical spring in one embodiment.

[0013] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0014] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0015] It is understood that the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0016] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0017] Example 1 like Figure 1 As shown, a multi-scale analysis method for the high-temperature relaxation behavior of a helical spring is provided, including the following steps: Step 201: Based on the geometric parameters and axial compression conditions of the target helical spring, and taking into account the characteristic that the stress is uniformly distributed along the helix under axial compression, a helical coil segment of a preset proportion is selected as the analysis unit. After verification through equivalent boundary conditions and simulation, a simplified micro-coil geometric model consistent with the mechanical response of the complete helical spring is output.

[0018] Step 202: Using the simplified microcoil geometric model as the geometric carrier, import the polycrystalline microstructure parameters to construct a polycrystalline model containing crystallographic features; mesh the polycrystalline model and apply corresponding boundary conditions to obtain a finite element solvable model.

[0019] Step 203: Based on the thermally activated crystal plastic finite element method, the constitutive parameters at a set high temperature are assigned to the finite element solvable model, and high-temperature stress relaxation simulation calculation is performed to obtain the stress cloud diagram.

[0020] Step 204: Based on the stress cloud diagram, calculate the volume average stress at the corresponding time step to obtain the relaxation degradation curve of the target helical spring.

[0021] In the aforementioned multi-scale analysis method for the high-temperature relaxation behavior of helical springs, the computational order of complex helical structures is reduced by truncating mechanically equivalent micro-coil segments. Polycrystalline microstructures are directly constructed on component-level models and coupled with thermally activated crystal plastic constitutive models. This method not only overcomes the engineering application bottleneck of excessively high computational costs of full-size polycrystalline models, but also avoids the oversimplification of stress gradients in the spring wire cross-section by homogenization methods. It can establish a quantitative correlation between microstructural characteristics such as grain size, phase ratio, and texture orientation and the macroscopic relaxation degradation performance of helical springs under controllable computing power. This method can provide reliable technical support for the relaxation resistance assessment and multi-scale refined design of elastic elements under high-temperature preload conditions.

[0022] In step 201, the simplified microcoil geometric model refers to the local coil segment analysis model that is equivalent to the mechanical response of the complete helical spring, which is used to reduce the scale of simulation calculation while ensuring the accuracy of analysis.

[0023] In the specific implementation of this step, the geometric parameters and axial compression conditions of the target helical spring are first obtained. The geometric parameters include the wire diameter. , outer diameter Free length and effective number of revolutions Axial compression conditions include axial deformation displacement. With service environment temperature Based on the characteristic that the stress is uniformly distributed along the helix under axial compression, a helical coil segment of a predetermined proportion is selected as the analysis unit.

[0024] Preferably, a simplified equivalent micro-coil model is constructed by selecting the cylindrical segment of the target helical spring's 2% coil. Then, the equivalent parameters corresponding to the analysis unit are calculated. These equivalent parameters include the equivalent coil wire diameter, the number of equivalent coils, the equivalent coil length, and the equivalent axial deformation displacement. The calculation is performed using the following formula: Equivalent coil wire diameter: .

[0025] Equivalent number of coils: .

[0026] Equivalent coil length: .

[0027] Equivalent axial deformation displacement: .

[0028] Subsequently, based on the equivalent parameters, equivalent boundary conditions coupling axial displacement constraints and circumferential rotation constraints were applied to both ends of the analysis unit. Specifically, the axial deformation direction of the microcoil was set along the X-axis of the model coordinate system, and the X-direction deformation displacement applied to the left end face was... Apply rotation in the Y-axis direction The coordinate system of the rotation axis is: ,in, The helix angle of the coil segment is defined; the deformation displacement in the X direction applied to the right end face is... Apply rotation in the Y-axis direction The coordinate system of the rotation axis is: .

[0029] Finally, based on equivalent boundary conditions, static and relaxation mechanical response simulations were performed on the analysis unit. The stress distribution characteristics, volume-average stress values, and relaxation degradation trajectories of the complete helical spring and microcoil models were compared, and a simplified microcoil geometric model consistent with the mechanical response of the complete helical spring was output. In this embodiment, the schematic diagrams of the target helical spring and the simplified microcoil geometric model are shown below. Figure 2 , Figure 3 As shown, the static simulation verification results of the two are as follows: Figure 4 As shown, the results of the relaxation mechanical response verification are as follows: Figure 5As shown, the stress distribution of the simplified micro-coil geometric model and the full model helical spring are basically consistent. The average body force of the two models is 145.98 MPa and 146.83 MPa, respectively, with an error of 0.579%, indicating that the equivalent model is effective.

[0030] This step achieves structural order reduction by assuming uniform stress distribution. Combined with equivalent boundary conditions of displacement-rotation coupling and two-dimensional simulation verification, it significantly reduces the geometric size and mesh scale of the model while fully preserving the stress characteristics of the helical spring bending-torsional coupling. This ensures that the boundary conditions of subsequent multi-scale analysis are consistent with the actual service conditions, thus balancing computational cost and analysis accuracy from the root.

[0031] In step 202, the polycrystalline model is a three-dimensional geometric model that includes the crystallographic features of the material, used to introduce microstructure parameters into component-level simulation analysis; the finite element solveable model is an analysis model that can be directly used for numerical calculation after mesh generation, attribute assignment and boundary loading are completed.

[0032] In the specific implementation of this step, a simplified microcoil geometric model is first used as the geometric boundary input, and then polycrystalline microstructure parameters are imported. Preferably, the target helical spring is a titanium alloy helical spring, and more preferably, a TC4 titanium alloy helical spring is used. The polycrystalline microstructure parameters include three categories: two-phase volume fraction, grain size, and texture orientation, which can cover the core microscopic influencing factors affecting high-temperature relaxation performance.

[0033] Subsequently, a polycrystalline model incorporating crystallographic features was constructed; titanium alloys were then allocated according to two-phase volume fractions. phase and The spatial occupancy of the phases is used to generate a polycrystalline three-dimensional topology based on the grain size. Then, based on the polycrystalline three-dimensional topology, Euler angle properties corresponding to the texture orientation are matched to each grain, ultimately generating a polycrystalline model containing crystallographic features. In this embodiment, three polycrystalline models with different microstructures are constructed, corresponding to 50 grains, 100 grains, and 300 grains, respectively. Figure 6 As shown.

[0034] After completing the polycrystalline modeling, the polycrystalline model is discretized into a mesh, resulting in a polycrystalline mesh model. Preferably, tetrahedral elements are used to mesh the polycrystalline model. Each grain element of the polycrystalline mesh model is assigned the material properties and crystal orientation information of the corresponding phase, ensuring that each mesh element belongs to a specific phase and matches the corresponding crystallographic parameters. Equivalent boundary conditions, coupling axial displacement constraints and circumferential rotation constraints, are applied to both ends of the polycrystalline mesh model. The configuration rules for the boundary conditions are consistent with those in step 201. After completing the mesh generation, attribute assignment, and boundary condition loading, a finite element solveable model is output. In this embodiment, the mesh generation and boundary condition settings of the polycrystalline model are illustrated as follows: Figure 7 As shown.

[0035] This step uses an equivalent microcoil as the geometric carrier to complete the component-level polycrystalline modeling. It directly preserves the microscopic features such as grains, phase boundaries and orientation distribution at the spring wire cross-sectional scale, without the need to convert the macroscopic constitutive model through homogenization methods. It naturally preserves the coupling effect between the cross-sectional stress gradient and the microstructure, providing an accurate geometric and property carrier for subsequent cross-scale relaxation behavior analysis.

[0036] In step 203, the thermally activated crystal plastic finite element method is a numerical analysis method that describes the plastic deformation behavior of materials based on the microscopic mechanism of dislocation thermal activation. It is used to accurately reproduce the stress relaxation evolution process of a helical spring at high temperature.

[0037] In the specific implementation of this step, a constitutive system is first constructed based on the thermally activated crystal plastic finite element method. Considering the influence of thermal deformation under high-temperature conditions, the total deformation gradient is decomposed multiplicatively into elastic deformation, plastic deformation, and thermal deformation components: ; In the formula, This represents the total deformation gradient; The elastic deformation gradient; The plastic deformation gradient; This represents the thermal deformation gradient.

[0038] The mechanical stress component of the deformation gradient is then... And mechanical deformation gradient Includes plastic deformation gradient and elastic deformation gradient : .

[0039] The volume remains constant during plastic deformation, that is... The plastic velocity gradient is obtained by summing the slip ratios of each slip system: ; In the formula, For the first The slip direction of the slip system; For the first Normal to the slip surface of a slip system For the first Shear strain rate of a slip system.

[0040] After completing the kinematic framework of the constitutive system, constitutive parameters at a set high temperature are assigned to the finite element solveable model. This is specifically for titanium alloys. phase and The phase grains are respectively configured with corresponding slip constitutive structures, wherein, The phase grains were modeled using a thermally activated slip model. The phase grains adopt a rate-dependent power-law thermally activated slip model.

[0041] The thermally activated slip model is constructed based on the dislocation thermal activation mechanism, and its expression is: ; In the formula, For the first Shear strain rate of the slip system; For the first Shear stress of a slip system; For the first Critical shear stress of a slip system; For the density of dislocations; For the first Burgers vectors of a slip system; This is the frequency of the Debye dislocation vibration. Boltzmann constant; The helix angle is segmented into sections for the coil segment; The service environment temperature; The Helmhotz activation energy, The activation volume.

[0042] Preferably, the activation volume can be calculated in the following two ways: or In the formula, The activation volume coefficient, , is a material constant.

[0043] The rate-dependent power-law thermally activated slip model describes the shear strain rate caused by slip in a phenomenological form, and its expression is: ; In the formula, For reference slip rate; For the first Back stress of a slip system; This is the strain rate sensitivity index.

[0044] The critical resolved shear stress of each slip system dynamically evolves during plastic deformation. The evolution rule is defined by a hardening model and used to characterize the increase in slip resistance caused by dislocation multiplication and interaction. The expression for the rate of change of critical resolved shear stress is: ; Among them, the slip hardening modulus is used to reflect the increase in slip resistance caused by dislocation multiplication and interaction during deformation. When Time is a self-hardening matrix. Time is the latent hardening matrix, expressed as: ; The self-hardening rate evolution adopts the Voce-type hardening law, characterizing the characteristic that the hardening rate gradually decreases and approaches saturation as deformation progresses. The expression is: ; In the formula, For the first The rate of change of critical shear stress in a slip system; For the first The slip system is related to the first One slip hardening modulus; The ratio of the self-hardening to the latent hardening strength of the slip system represents the relative strength of the self-hardening and latent hardening of the slip system. The Kronecker function; For the first Reference value for the self-hardening modulus of a slip system; No. The self-hardening rate of a slip system; Reference hardening modulus (MPa); Saturated slip resistance (MPa); For the first Critical shear stress of a slip system; For the first Shear strain rate of the slip system; This is the hardening index.

[0045] After assigning constitutive parameters, a high-temperature stress relaxation simulation is performed. Using a finite element solveable model with equivalent boundary conditions and constitutive parameters as input, the first analysis step is set, and the axial displacement and circumferential rotation constraints are linearly applied to the target values ​​within a preset loading time to complete the pre-tightening deformation loading and obtain the initial stress state of the model.

[0046] The second analysis step is set up with the initial stress state as the starting point of the calculation. The values ​​of axial displacement and circumferential rotation constraints are kept constant. Stress relaxation calculation of constant deformation constraint is performed under the set high temperature environment. Within the preset total calculation time, the slip strain, critical shear stress and stress field of each mesh element are updated according to the set time step, and the global stress field data corresponding to each time step is output.

[0047] Based on global stress field data, the stress distribution results of the model are extracted at each calculation time step to generate a stress cloud map for the corresponding time step.

[0048] Preferably, the loading time of the first analysis step is set to 2 seconds, and the total calculation time of the second analysis step is set to 1000 seconds, matching the working condition characteristics of a helical spring under long-term preload service. In this embodiment, the relaxation degradation simulation stress cloud diagrams under different grain sizes are as follows: Figure 8 As shown.

[0049] This step uses a slip model based on the dislocation thermal activation mechanism to describe... The phase-dominated high-temperature deformation behavior, combined with phase-separated constitutive configuration and dynamic hardening evolution system, can accurately reproduce the stress relaxation process dominated by high-temperature creep at the microscopic mechanism level. By using a two-step simulation method of loading and holding to realistically simulate the complete working conditions of pre-tightening and service, the output global stress field can fully present the stress gradient distribution and evolution law of the spring wire cross section, providing an accurate field data basis for subsequent quantitative analysis of relaxation performance.

[0050] In step 204, the relaxation degradation curve is a quantitative curve that characterizes the attenuation of stress in a helical spring over service time, and is used to visually assess the relaxation resistance of the material.

[0051] In the specific implementation of this step, based on the stress cloud map, the volumetric average stress corresponding to each time step is calculated by volume-weighted integration of the global stress field data corresponding to each time step.

[0052] The volumetric average stress at the initial moment is extracted as the reference value. The volumetric average stress at each time step is then compared with the reference value to obtain the normalized stress value at each time step.

[0053] A normalized high-temperature stress relaxation curve is generated by plotting time on the x-axis and normalized stress value on the y-axis, and output as the relaxation degradation curve of the target helical spring. In this embodiment, the normalized relaxation degradation curves corresponding to different grain sizes are as follows: Figure 9 As shown, the effect of grain refinement on relaxation resistance can be directly compared.

[0054] This step achieves quantitative characterization of the global stress field through volume-weighted integration. Combined with normalization processing, the influence of initial load differences is eliminated. The output relaxation degradation curve can be directly used to compare the relaxation resistance differences of helical springs under different microstructure parameters, providing an intuitive quantitative basis for material selection and microstructure optimization.

[0055] It should be understood that, although this embodiment Figure 1 The steps are shown sequentially as indicated by the arrows, but they are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order in which these steps are performed; they can be executed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed 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 some of the sub-steps or stages of other steps.

[0056] Example 2 Based on the multi-scale analysis method for the high-temperature relaxation behavior of helical springs in Example 1, this example discloses a multi-scale analysis device for the high-temperature relaxation behavior of helical springs, such as... Figure 10 As shown, the multi-scale analysis device for the high-temperature relaxation behavior of helical springs includes: a simplified micro-coil geometric model construction module 401, a finite element solvable model construction module 402, a stress cloud diagram calculation module 403, and a relaxation degradation curve calculation module 404, wherein: The simplified microcoil geometry model construction module 401 is used to select a pre-proportioned segment of the helical coil as the analysis unit based on the geometric parameters and axial compression conditions of the target helical spring and the characteristic that the stress is uniformly distributed along the helix under axial compression. After equivalent boundary conditions and simulation verification, it outputs a simplified microcoil geometry model that is consistent with the mechanical response of the complete helical spring.

[0057] The finite element solveable model construction module 402 is used to construct a polycrystalline model containing crystallographic features by importing polycrystalline microstructure parameters using a simplified microcoil geometric model as the geometric carrier; meshing the polycrystalline model and applying corresponding boundary conditions to obtain a finite element solveable model.

[0058] The stress cloud diagram calculation module 403 is used to assign constitutive parameters at a set high temperature to the finite element solvable model based on the thermally activated crystal plastic finite element method, perform high temperature stress relaxation simulation calculation, and obtain stress cloud diagram.

[0059] The relaxation degradation curve calculation module 404 is used to calculate the volume average stress at the corresponding time step based on the stress cloud diagram, and obtain the relaxation degradation curve of the target helical spring.

[0060] In this embodiment, the specific working process and working principle of the simplified micro-coil geometric model construction module 401, the finite element solvable model construction module 402, the stress cloud diagram calculation module 403, and the relaxation degradation curve calculation module 404 are the same as those in Embodiment 1, and therefore will not be described again in this embodiment. Each unit module can be implemented entirely or partially through software, hardware, or a combination thereof. Each unit module can be embedded in or independent of the processor in a computer device in hardware form, or it can be stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each of the above unit modules.

[0061] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A multi-scale analysis method for the high-temperature relaxation behavior of a helical spring, characterized in that, The method includes: Based on the geometric parameters and axial compression conditions of the target helical spring, and taking into account the characteristic that the stress is uniformly distributed along the helix under axial compression, a helical coil segment of a preset proportion is selected as the analysis unit. After verification through equivalent boundary conditions and simulation, a simplified micro-coil geometric model consistent with the mechanical response of the complete helical spring is output. Using the simplified microcoil geometric model as the geometric carrier, polycrystalline microstructure parameters are imported to construct a polycrystalline model containing crystallographic features; the polycrystalline model is meshed and corresponding boundary conditions are applied to obtain a finite element solvable model. Based on the thermally activated crystal plastic finite element method, constitutive parameters at a set high temperature are assigned to the finite element solvable model, and high-temperature stress relaxation simulation calculation is performed to obtain stress cloud diagram; Based on the stress cloud diagram, the volume average stress at the corresponding time step is calculated to obtain the relaxation degradation curve of the target helical spring.

2. The multi-scale analysis method for high-temperature relaxation behavior of helical springs according to claim 1, characterized in that, The process of obtaining a simplified microcoil geometric model includes: Based on the geometric parameters and axial compression conditions of the target helical spring, the equivalent parameters corresponding to the analysis unit are calculated; Based on the equivalent parameters, equivalent boundary conditions coupling axial displacement constraints and circumferential rotation constraints are applied to both ends of the analysis unit. Based on the equivalent boundary conditions, the static and relaxation mechanical responses of the analysis unit are simulated and verified, and a simplified micro-coil geometric model consistent with the mechanical response of the complete helical spring is output.

3. The multi-scale analysis method for high-temperature relaxation behavior of helical springs according to claim 1, characterized in that, The target helical spring is a titanium alloy helical spring, and the structure includes a polycrystalline model with crystallographic features, comprising: Using the simplified microcoil geometric model as the geometric boundary input, import polycrystalline microstructure parameters including two-phase volume fraction, grain size, and texture orientation; Titanium alloys allocated according to two-phase volume fraction phase and The spatial proportion of the phase is used to generate a polycrystalline three-dimensional topological structure based on the grain size. Based on the three-dimensional topology of the polycrystalline grains, Euler angle properties corresponding to the texture orientation are matched for each grain to generate a polycrystalline model containing crystallographic features.

4. The multi-scale analysis method for high-temperature relaxation behavior of helical springs according to claim 3, characterized in that, The polycrystalline model is meshed and corresponding boundary conditions are applied to obtain a finite element solvable model, including: The polycrystalline model is discretized into a grid to obtain a polycrystalline mesh model; Assign material properties and crystal orientation information of the corresponding phase to each grain unit of the polycrystalline mesh model; An equivalent boundary condition, coupling axial displacement constraint and circumferential rotation constraint, is applied to both ends of the polycrystalline mesh model. After completing mesh generation, attribute assignment, and boundary condition loading, a finite element solveable model is output.

5. The multi-scale analysis method for the high-temperature relaxation behavior of helical springs according to claim 3 or 4, characterized in that, When assigning constitutive parameters at a set high temperature to the finite element solveable model, for titanium alloys... phase and The phase grains are respectively configured with corresponding slip constitutive structures, wherein, The phase grains were modeled using a thermally activated slip model. The phase grains adopt a rate-dependent power-law thermally activated slip model.

6. The multi-scale analysis method for high-temperature relaxation behavior of helical springs according to claim 5, characterized in that, The thermally activated slip model in the thermally activated crystal plastic finite element method is as follows: ； In the formula, For the first Shear strain rate of the slip system; For the first Shear stress of a slip system; For the first Critical shear stress of a slip system; For the density of dislocations; For the first Burgers vectors of a slip system; This is the frequency of the Debye dislocation vibration. Boltzmann constant; The helix angle is segmented into sections for the coil segment; The service environment temperature; The Helmhotz activation energy, The activation volume.

7. The multi-scale analysis method for high-temperature relaxation behavior of helical springs according to claim 6, characterized in that, The critical shear stress of the slip system evolves dynamically with the plastic deformation process. The evolution rule is defined by the hardening model, and the expression is: ； in, ； ； In the formula, For the first The rate of change of critical shear stress in a slip system; For the first The slip system is related to the first One slip hardening modulus; This represents the ratio of self-hardening to latent hardening strength in a slip system. The Kronecker function; For the first Reference value for the self-hardening modulus of a slip system; No. The self-hardening rate of a slip system; For reference hardening modulus; This represents saturated slip resistance. For the first Critical shear stress of a slip system; For the first Shear strain rate of the slip system; This is the hardening index.

8. The multi-scale analysis method for the high-temperature relaxation behavior of helical springs according to claim 6 or 7, characterized in that, Perform high-temperature stress relaxation simulation calculations to obtain stress contour plots, including: Using a finite element solveable model with equivalent boundary conditions and constitutive parameters as input, the first analysis step is set, and the axial displacement and circumferential rotation constraints are linearly loaded to the target value within a preset loading time to complete the pre-tightening deformation loading and obtain the initial stress state of the model. The second analysis step is set up, taking the initial stress state as the calculation starting point, keeping the values ​​of axial displacement and circumferential rotation constraints constant, performing stress relaxation calculation of constant deformation constraints under a set high temperature environment, and updating the slip strain, critical shear stress and stress field of each mesh element according to the set time step within the preset total calculation time, and outputting the global stress field data corresponding to each time step. Based on the global stress field data, the stress distribution results of the model are extracted at each calculation time step to generate the stress cloud map for the corresponding time step.

9. The multi-scale analysis method for high-temperature relaxation behavior of helical springs according to claim 8, characterized in that, Based on the stress cloud diagram, the volume average stress at the corresponding time step is calculated, and the relaxation degradation curve of the target helical spring is obtained, including: Based on the stress cloud map, the volume average stress corresponding to each time step is calculated by volume-weighted integration of the global stress field data corresponding to each time step. The volume average stress at the initial moment is extracted as the reference value. The volume average stress at each time step is then compared with the reference value to obtain the normalized stress value at each time step. Plot the normalized high-temperature stress relaxation curve with time as the x-axis and the normalized stress value as the y-axis, and use it as the relaxation degradation curve of the target helical spring.

10. A multi-scale analysis device for the high-temperature relaxation behavior of a helical spring, characterized in that, The device includes: The simplified microcoil geometry model construction module is used to select a pre-proportioned segment of the helical coil as the analysis unit based on the geometric parameters and axial compression conditions of the target helical spring and the characteristic that the stress is uniformly distributed along the helix under axial compression. After equivalent boundary conditions and simulation verification, it outputs a simplified microcoil geometry model that is consistent with the mechanical response of the complete helical spring. The finite element solveable model construction module is used to construct a polycrystalline model containing crystallographic features by importing polycrystalline microstructure parameters using the simplified microcoil geometric model as the geometric carrier; meshing the polycrystalline model and applying corresponding boundary conditions to obtain a finite element solveable model. The stress cloud diagram calculation module is used to assign constitutive parameters at a set high temperature to the finite element solvable model based on the thermally activated crystal plastic finite element method, perform high temperature stress relaxation simulation calculation, and obtain stress cloud diagram; The relaxation degradation curve calculation module is used to calculate the volume average stress at the corresponding time step based on the stress cloud diagram, and obtain the relaxation degradation curve of the target helical spring.

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