Stress evaluation method, device and equipment of honeycomb structure and storage medium

Abstract

The invention relates to the technical field of mechanical property evaluation, and discloses a stress evaluation method and device for a honeycomb structure, equipment and a storage medium. The stress evaluation method of the honeycomb structure comprises the following steps: acquiring an evaluation request containing a cell size factor of the honeycomb structure, and determining the structure relative density, quasi-static failure stress and dynamic compaction strain of the honeycomb structure according to the cell size factor; and determining dynamic impact platform stress of the honeycomb structure according to the structure relative density, the quasi-static failure stress and the dynamic compaction strain, and obtaining an evaluation result corresponding to the evaluation request according to the dynamic impact platform stress. According to the method, the influence of the size effect and the inertia effect under the dynamic impact on the impact platform stress is comprehensively considered, and the accuracy of the evaluation result of the dynamic impact platform stress is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical performance evaluation, and in particular to a stress evaluation method, device, equipment and storage medium for a honeycomb structure. Background Art

[0002] Honeycomb structure is a typical porous material. In the related art, for the hexagonal honeycomb structure, there is a method of first calculating the total bending deformation energy and total film deformation energy absorbed by the four additional planar units of the honeycomb structure, and then calculating the axial compressive stress of the hexagonal honeycomb under axial compression to evaluate its mechanical properties. This scheme has the following problems: On the one hand, the effect of the cell size on the mechanical properties is ignored, and the size effect will affect the accuracy of the evaluation of the mechanical properties of the honeycomb structure. On the other hand, this scheme does not reflect the strengthening effect of the inertial effect under dynamic impact on the platform stress of the honeycomb structure, which further leads to a significant deviation between the evaluation results and the actual results, thereby affecting the effectiveness of the evaluation of the energy absorption application effect of the honeycomb structure. Summary of the invention

[0003] Based on this, it is necessary to provide a stress assessment method, device, equipment and storage medium for a honeycomb structure in order to solve the problem of inaccurate assessment results of the mechanical properties of honeycomb structures in the prior art.

[0004] A stress assessment method for a honeycomb structure, comprising:

[0005] Obtaining an evaluation request including a cell size factor of a honeycomb structure, and determining a structural relative density, a quasi-static failure stress, and a dynamic densification strain of the honeycomb structure according to the cell size factor;

[0006] The dynamic impact platform stress of the honeycomb structure is determined according to the structural relative density, the quasi-static failure stress and the dynamic compaction strain, and an evaluation result corresponding to the evaluation request is obtained according to the dynamic impact platform stress.

[0007] A stress assessment device for a honeycomb structure, comprising:

[0008] A cell size factor processing module, used to obtain an evaluation request for a cell size factor of a honeycomb structure, and determine a relative structural density, a quasi-static failure stress, and a dynamic densification strain of the honeycomb structure according to the cell size factor;

[0009] An impact platform stress determination module is used to determine the dynamic impact platform stress of the honeycomb structure according to the relative density of the structure, the quasi-static failure stress and the dynamic compaction strain, and obtain an evaluation result corresponding to the evaluation request according to the dynamic impact platform stress.

[0010] A computer device comprises a memory, a processor and computer-readable instructions stored in the memory and executable on the processor, wherein the processor implements the stress assessment method of the honeycomb structure when executing the computer-readable instructions.

[0011] A computer-readable storage medium stores computer-readable instructions. When the computer-readable instructions are executed by one or more processors, the one or more processors execute the stress assessment method for a honeycomb structure as described above.

[0012] In the stress assessment method, device, equipment and storage medium of the honeycomb structure, the stress assessment method of the honeycomb structure introduces the cell size factor in the assessment request, and determines the structural relative density, quasi-static failure stress and dynamic compaction strain of the honeycomb structure based on the cell size factor, which helps to achieve the theoretical calculation of the impact platform stress of the honeycomb structure under different cell sizes, quantitatively analyzes the influence of the size effect on the mechanical properties of the honeycomb structure, and improves the accuracy of stress assessment. At the same time, the present invention further determines the dynamic impact platform stress of the honeycomb structure based on the structural relative density, quasi-static failure stress and dynamic compaction strain, comprehensively considers the influence of the size effect and the inertial effect under dynamic impact on the impact platform stress, improves the accuracy of the dynamic impact platform stress assessment, and helps to ensure the effectiveness of the energy absorption effect assessment and performance-oriented design of the honeycomb structure based on the assessment results. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0014] Figure 1 is a schematic diagram of a process of a stress evaluation method for a honeycomb structure in one embodiment of the present invention;

[0015] Figure 2 is a schematic diagram of a cell structure of a stress evaluation method for a honeycomb structure in one embodiment of the present invention;

[0016] Figure 3 is a schematic diagram of a structure of a cell before compression in a method for stress evaluation of a honeycomb structure in one embodiment of the present invention;

[0017] Figure 4 is a schematic diagram of a structure of a cell after compression in a stress evaluation method for a honeycomb structure in one embodiment of the present invention;

[0018] Figure 5is a schematic structural diagram of a stress evaluation device of a honeycomb structure in one embodiment of the present invention;

[0019] Figure 6 is a schematic diagram of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In one embodiment, if Figure 1 As shown, a stress assessment method for a honeycomb structure is provided, comprising the following steps S10-S20:

[0022] S10, obtaining an evaluation request including a cell size factor of a honeycomb structure, and determining a structural relative density, a quasi-static failure stress, and a dynamic densification strain of the honeycomb structure according to the cell size factor.

[0023] Understandably, the evaluation request refers to the request information for evaluating the dynamic impact platform stress of the honeycomb structure. The evaluation request includes the inherent attribute parameter information required for evaluating the dynamic impact platform stress of the honeycomb structure, such as the wall thickness, wall length, cell size factor and structural material density of the honeycomb structure. Cell refers to the smallest unit of the honeycomb structure. The cell size factor is information used to characterize the number of cells within the macroscopic size of the polyhedral structure, and the cell size factor is a positive integer. Figure 2 As shown in the figure, the regular hexagonal unit represents the cell, the side of the regular hexagon represents the cell wall, S represents the macroscopic size of the honeycomb structure, and n represents the cell size factor. When the macroscopic size of the honeycomb structure remains unchanged, if the cell size factor is 1, the honeycomb structure is a single-cell structure, and if the cell size factor is greater than 1, the honeycomb structure is a multi-cell structure. By changing the cell size factor, the relative size between the honeycomb structure and the cell can be changed while maintaining the basic configuration of the cell.

[0024] Based on the cell size factor, a series of theoretical models (such as preset relative density model, preset quasi-static stress model and preset dynamic compaction strain model, etc.) can be used to obtain the structural relative density, quasi-static failure stress and dynamic compaction strain of the honeycomb structure. The structural relative density refers to the ratio of the equivalent density of the honeycomb structure to the material density of the cell wall material. According to different impact velocities, the mechanical behavior of the honeycomb structure can be divided into static, quasi-static and dynamic responses. The static, quasi-static and dynamic responses correspond to low-speed, medium-speed and high-speed impacts, respectively. The load corresponding to the static response and quasi-static response of the honeycomb structure is called the static compression load, and the load corresponding to the dynamic response of the honeycomb structure is called the dynamic impact load. The quasi-static response is a transition state or critical state between the static response and the dynamic response, that is, the mechanical parameters of the quasi-static response are the maximum critical values ​​under the static response. The honeycomb structure exhibits different deformation modes and failure mechanisms under low-speed, medium-speed and high-speed impacts. Due to the inertia effect, the stress level and strain rate under the dynamic response are higher than those under the static response and quasi-static response. The quasi-static failure stress refers to the stress of the honeycomb structure under the quasi-static response. Dynamic densification strain refers to the strain of the honeycomb structure under dynamic response. The strain of the honeycomb structure under different impact velocities is different. When the honeycomb structure reaches densification (maximum strain) under dynamic response, the porous structure of the honeycomb structure is completely destroyed (reaching a solid structure), and the equivalent density of the honeycomb structure is equal to the material density of the cell wall material.

[0025] S20, determining the dynamic impact platform stress of the honeycomb structure according to the relative density of the structure, the quasi-static failure stress and the dynamic compaction strain, and obtaining an evaluation result corresponding to the evaluation request according to the dynamic impact platform stress.

[0026] Understandably, the honeycomb structure will undergo plastic deformation under the action of dynamic impact loads, and the stress will show three different stages including elastic stage, platform stage and densification stage. Among them, the platform stage with stable stress and longest travel determines the energy absorption level of the honeycomb structure in practical applications, especially the dynamic response under high-speed impact. Dynamic impact platform stress refers to the stress corresponding to the platform stage of the honeycomb structure under the action of dynamic impact loads. Therefore, the dynamic impact platform stress of the honeycomb structure under the platform stage is of great significance to the impact energy absorption design of the honeycomb structure. This embodiment establishes a theoretical model (preset dynamic impact stress model) based on the relationship between the dynamic impact platform stress and the relative density of the structure, the quasi-static failure stress, and the dynamic densification strain, so that under the premise of known relative density of the structure, quasi-static failure stress and dynamic densification strain, the dynamic impact platform stress of the honeycomb structure is obtained through the theoretical model, and the obtained dynamic impact platform stress is determined as the evaluation result corresponding to the evaluation request.

[0027] This embodiment introduces the cell size factor in the evaluation request, and determines the relative structural density, quasi-static failure stress, and dynamic compaction strain of the honeycomb structure based on the cell size factor, which helps to achieve the theoretical calculation of the impact platform stress of the honeycomb structure under different cell sizes, quantitatively analyze the influence of the size effect on the mechanical properties of the honeycomb structure, and improve the accuracy of stress evaluation. At the same time, this embodiment further determines the dynamic impact platform stress of the honeycomb structure based on the relative structural density, quasi-static failure stress, and dynamic compaction strain, comprehensively considers the influence of the size effect and the inertial effect under dynamic impact on the impact platform stress, improves the accuracy of the dynamic impact platform stress evaluation, and helps to ensure the effectiveness of the energy absorption effect evaluation and performance-oriented design of the honeycomb structure based on the evaluation results.

[0028] In one embodiment, step S10, i.e. determining the structural relative density of the honeycomb structure according to the cell size factor, includes:

[0029] S101, determining the relative wall length and relative wall thickness of each cell according to the cell size factor;

[0030] S102, determining the relative structural density of the honeycomb structure according to the relative wall length dimension and the relative wall thickness dimension.

[0031] In one embodiment, in step S102, determining the relative structural density of the honeycomb structure according to the relative wall length and the relative wall thickness includes:

[0032] S1021. Process the relative wall length and the relative wall thickness through a preset relative density model to obtain a relative density of the structure. The preset relative density model includes:

[0033]

[0034] Among them, ρ r Indicates the relative density of the structure;

[0035] t / n represents the relative wall thickness;

[0036] l / n represents the relative wall length dimension;

[0037] n represents the cell size factor;

[0038] t represents the thickness of the cell wall;

[0039] l represents the length of the cell wall.

[0040] It can be understood that when the macroscopic size S of the honeycomb structure remains unchanged, if the cell size factor n is 1, the honeycomb structure is a single cell structure, such as Figure 3As shown in the figure, the sides of the regular hexagon represent the cell walls, t represents the thickness of the cell wall, and l represents the length of the cell wall. If the cell size factor is greater than 1, the honeycomb structure is a multi-cell structure, such as Figure 2 As shown, l / n represents the relative wall length dimension, and t / n represents the relative wall thickness dimension (not shown in the figure). The relative wall length dimension refers to the wall length dimension of the cell relative to the single cell structure when the honeycomb structure is a multi-cell structure, and the relative wall thickness dimension refers to the wall thickness dimension of the cell relative to the single cell structure when the honeycomb structure is a multi-cell structure. The preset relative density model is a pre-established theoretical calculation model for calculating the relative density of the structure.

[0041] In one embodiment, the single cell wall length and single cell wall thickness are obtained when the honeycomb structure is a single cell structure, and when the cell size factor is greater than 1, the honeycomb structure is determined to be a multi-cell structure, and the relative wall length and relative wall thickness of each cell are determined according to the cell size factor. The relative wall length and relative wall thickness determined by the preset relative density model are processed to obtain the relative density of the structure.

[0042] This embodiment defines the relative wall length and relative wall thickness of the honeycomb structure based on the cell size factor by introducing the cell size factor, and obtains the relative density of the structure by presetting the relative density model, which fully considers the size effect when the honeycomb structure is a multi-cellular structure.

[0043] In one embodiment, step S10, i.e., determining the quasi-static failure stress according to the cell size factor, includes:

[0044] S103, obtaining a material yield stress obtained by performing a quasi-static compression test on the honeycomb structure;

[0045] S104, determining a quasi-static failure stress according to the material yield stress, the relative wall length dimension, and the relative wall thickness dimension.

[0046] In one embodiment, in step S104, determining the quasi-static failure stress according to the material yield stress, the relative wall length dimension and the relative wall thickness dimension includes:

[0047] S1041. Process the material yield stress, the relative wall length dimension, and the relative wall thickness dimension through a preset quasi-static stress model to obtain a quasi-static failure stress. The preset quasi-static stress model includes:

[0048]

[0049] Where σ0 represents the quasi-static failure stress;

[0050] t / n represents the relative wall thickness;

[0051] l / n represents the relative wall length dimension;

[0052] n represents the cell size factor;

[0053] t represents the thickness of the cell wall;

[0054] l represents the length of the single cell wall;

[0055] σ ys Represents the material yield stress.

[0056] Understandably, the quasi-static compression test is a condition for applying a static compression load to a honeycomb structure to cause the honeycomb structure to respond quasi-statically. The material yield stress refers to the yield stress of the solid material constituting the cell wall. The preset quasi-static stress model is a pre-established theoretical calculation model for calculating the quasi-static failure stress. Before processing the material yield stress, relative wall length and relative wall thickness through the preset quasi-static stress model, it is necessary to first establish a preset quasi-static stress model based on the plastic hinge energy equivalence principle. Figure 3 As shown in , before the cell of the honeycomb structure is compressed, θ represents the internal angle of the cell of the honeycomb structure. For the regular hexagonal cell, the internal angle of the cell is 30°. Figure 4 As shown, σ0 represents the quasi-static failure stress, that is, the static compression load under the quasi-static compression test. After the cell of the honeycomb structure is compressed, the cell wall of the honeycomb structure undergoes plastic rotation, and the four plastic hinges A, B, C and D undergo plastic rotation. Rotation angle representing plastic rotation.

[0057] First, the work done by the quasi-static failure stress is P = σ0(t / n+l / n sinθ)b, where P represents the work done by the force, σ0 represents the quasi-static failure stress, t / n represents the relative wall thickness, l / n represents the relative wall length, and b represents the out-of-plane wall thickness. The honeycomb structure is a three-dimensional regular hexagonal structure. The regular hexagon is only the projection shape of the plane where the wall length and wall thickness are located. The out-of-plane wall thickness refers to the dimension used to characterize the thickness of the honeycomb structure in the direction perpendicular to the plane where the wall length and wall thickness are located. Secondly, based on the principle of plastic hinge energy equivalence, under the influence of the work done by the force P, the four plastic hinge points A, B, C and D rotate at an angle of The plastic rotation of the hinge is Among them, M p represents the pure plastic moment when the cell wall is bent. At the same time, the pure plastic moment is Among them, σ ys represents the material yield stress. Substituting the formula of pure plastic moment into the formula of plastic work, we can get In order to simplify the calculation, this embodiment takes an approximate value of 0.6, and the final preset quasi-static stress model is: The preset quasi-static stress model is used to characterize the quasi-static failure stress σ0.

[0058] This embodiment processes the material yield stress, relative wall length and relative wall thickness through a preset quasi-static stress model, and can obtain the quasi-static failure stress through a pre-established stress theoretical model of the honeycomb structure under quasi-static compression conditions, which fully considers the size effect when the honeycomb structure is a multi-cellular structure, and is helpful to quantitatively analyze the influence of the size effect on the quasi-static failure stress of the honeycomb structure.

[0059] In one embodiment, step S10, i.e. determining the dynamic densification strain according to the cell size factor, includes:

[0060] S105, obtaining a real-time impact velocity corresponding to a dynamic impact test on the honeycomb structure;

[0061] S106, determining a critical impact velocity according to the cell size factor;

[0062] S107. Determine a dynamic compaction strain according to the real-time impact velocity, the critical impact velocity, and the structural relative density.

[0063] In one embodiment, step S106, i.e., determining the critical impact velocity according to the cell size factor, includes:

[0064] S1061, obtaining the structural material density and the material yield stress of the honeycomb structure, processing the cell size factor, the structural material density and the material yield stress through a preset critical impact velocity model to obtain a critical impact velocity, wherein the preset critical impact velocity model includes:

[0065]

[0066]

[0067] Where V represents the critical impact velocity;

[0068] C represents the cell fitting coefficient;

[0069] σ ys Represents the material yield stress;

[0070] ρ s Indicates the density of structural materials;

[0071] C0 represents the basic fitting coefficient;

[0072] n represents the cell size factor.

[0073] In one embodiment, in step S107, determining the dynamic compaction strain according to the real-time impact velocity, the critical impact velocity and the structural relative density includes:

[0074] S1071, processing the real-time impact velocity, the critical impact velocity, and the structural relative density through a preset dynamic densification strain model to obtain a dynamic densification strain corresponding to the real-time impact velocity, wherein the preset dynamic densification strain model includes:

[0075]

[0076] Among them, ε d represents the dynamic compaction strain;

[0077] V0 represents the real-time impact velocity;

[0078] V w represents the critical impact velocity;

[0079] ρ r Represents the relative density of the structure.

[0080] Understandably, the dynamic impact test is a working condition for applying a dynamic impact load to a honeycomb structure so that the honeycomb structure responds dynamically. The real-time impact velocity refers to the impact velocity corresponding to the dynamic impact load actually applied to the honeycomb structure. The structural material density refers to the density of the solid material constituting the cell wall. The material yield stress refers to the yield stress of the solid material constituting the cell wall. Before processing the real-time impact velocity, critical impact velocity and structural relative density through a preset dynamic compaction strain model, it is necessary to first establish a preset critical impact velocity model and a preset dynamic compaction strain model. The preset critical impact velocity model is a pre-established theoretical calculation model for calculating the critical impact velocity. The preset dynamic compaction strain model is a pre-established theoretical calculation model for calculating the dynamic compaction strain.

[0081] When establishing the preset critical impact velocity model, the critical impact velocity is comprehensively considered to be affected by the cell geometry parameters and the cell wall material properties. Among them, the material yield stress σ ys and structural material density ρ s The cell fitting coefficient C indicates the influence of the cell wall material properties. Specifically, the cell fitting coefficient The basic fitting coefficient C0 has a value range of 1.0 to 2.0, and a default value can be set or adjusted according to actual needs.

[0082] Furthermore, considering that the densification strain shows obvious segmentation with the increase of real-time impact velocity, a preset dynamic densification strain model is established in the form of piecewise function.w When , the preset dynamic compaction strain model used to characterize the dynamic compaction strain is When V0>V w When , the preset dynamic compaction strain model used to characterize the dynamic compaction strain is ε d =1-ρ r , indicating that under the action of dynamic impact platform stress, the relative density of the structure ρ r The smaller the dynamic compaction strain ε d The bigger.

[0083] This embodiment determines different deformation modes of the honeycomb structure according to different real-time impact velocities, and then establishes a theoretical model of structural compaction strain related to the real-time impact velocity in the form of a piecewise function, thereby improving the prediction accuracy of the dynamic compaction strain. The real-time impact velocity, critical impact velocity, and structural relative density are processed by a preset dynamic compaction strain model, and the dynamic compaction strain is obtained by a pre-established strain theoretical model of the honeycomb structure under dynamic impact conditions. The cell fitting coefficient is introduced into the critical impact velocity, and the dynamic compaction strain fully considers the inertia effect under dynamic impact, which helps to analyze the influence of size effect and inertia effect on the dynamic compaction strain of the honeycomb structure.

[0084] In one embodiment, in step S20, determining the dynamic impact platform stress of the honeycomb structure according to the relative density of the structure, the quasi-static failure stress and the dynamic compaction strain includes:

[0085] S201, obtaining the structural material density of the honeycomb structure, and determining the structural equivalent density of the honeycomb structure according to the structural material density and the structural relative density;

[0086] S202, determining the dynamic impact platform stress of the honeycomb structure according to the structural equivalent density, the real-time impact velocity, the quasi-static failure stress, and the dynamic compaction strain.

[0087] It can be understood that when determining the structural equivalent density of the honeycomb structure based on the structural material density and the structural relative density, the structural material density and the structural relative density are processed by the preset equivalent density model to obtain the structural equivalent density. The structural equivalent density refers to the density of the honeycomb structure, that is, the ratio of the mass to the volume of the honeycomb structure. Since the honeycomb structure has holes, the structural equivalent density is less than the structural material density. The preset equivalent density model is a pre-established theoretical calculation model for calculating the structural equivalent density. Since the structural relative density ρ r =ρ0 / ρ s , then the default equivalent density model is ρ0=ρ r *ρ s , where ρ0 represents the structural equivalent density, ρ s Indicates the density of structural materials.

[0088] In one embodiment, in step S202, determining the dynamic impact platform stress of the honeycomb structure according to the structural equivalent density, the real-time impact velocity, the quasi-static failure stress and the dynamic compaction strain includes:

[0089] S2021. Processing the structural equivalent density, the real-time impact velocity, the quasi-static failure stress, and the dynamic compaction strain through a preset dynamic impact stress model to obtain a dynamic impact platform stress corresponding to the real-time impact velocity, wherein the preset dynamic impact stress model includes:

[0090]

[0091] Among them, σ p Represents dynamic impact stress;

[0092] σ0 represents the quasi-static failure stress;

[0093] ρ0 represents the structural equivalent density;

[0094] V0 represents the real-time impact velocity;

[0095] ε d represents the dynamic compaction strain.

[0096] Understandably, the preset dynamic impact stress model is a pre-established theoretical calculation model for calculating dynamic impact stress. Before processing the structural equivalent density, real-time impact velocity, quasi-static failure stress and dynamic compaction strain through the preset dynamic impact stress model, it is necessary to establish a preset dynamic impact stress model based on the Rigid-Perfectly-Plastic-Lock (RPPL) model. The Rigid-Perfectly-Plastic-Lock model is used to characterize the dynamic mechanical behavior of polyhedral materials (such as honeycomb structures) when subjected to dynamic impact loads. Among them, the Rigid stage indicates that the honeycomb structure remains rigid in the initial stage, and the stress increases rapidly with the increase of strain; the Perfectly-Plastic stage indicates that the honeycomb structure enters the plastic region, the stress is maintained at a relatively stable platform value, the strain continues to increase but the stress does not change much (i.e., dynamic impact platform stress); the Lock stage indicates that when the strain reaches a certain level, the honeycomb structure is compacted and the stress increases rapidly again.

[0097] First, based on the one-dimensional shock wave theory, it is assumed that the honeycomb structure is a shock wave-dominated dynamic response under the rigid-ideal plastic-locked model. The plastic work done during the impact compression process at the real-time impact velocity V0 can be expressed as σ0ε d Al / (1-ε d), where A represents the cross-sectional area of ​​the honeycomb structure subjected to dynamic impact load, which is assumed to be a constant. Secondly, based on the principle of energy conservation, it can be known that Where G represents the equivalent gravity of the dynamic impact load, V p represents the velocity of the particle in the densified region. Then, within the time increment δt, based on the principle of conservation of momentum per unit mass unit of the wavefront, we know that Among them, c p represents the propagation velocity of the plastic shock wave, and further simplified, we get Finally, according to the relationship between stress and particle velocity in the stress wave, the velocity V of the particle in the densified area can be known. p =c p ε d , and substitute this formula into After transformation, we get At the same time, when the length dimension l of the compressed honeycomb structure is 0, the maximum platform stress is reached. At this time, the dynamic impact platform stress of the honeycomb structure under the dynamic impact velocity V0 is obtained: That is, a preset dynamic impact stress model is established for characterizing the dynamic impact platform stress corresponding to the real-time impact velocity.

[0098] This embodiment is based on the rigid-ideal plastic-locking model, and introduces the quasi-static failure stress and dynamic compaction strain related to the size effect and the real-time impact velocity to establish a preset dynamic impact stress model. It quantitatively characterizes the strengthening effect of the structural impact platform stress under the dynamic impact condition, and comprehensively considers the influence of the size effect and the inertia effect of the dynamic impact on the dynamic impact platform stress, so as to accurately evaluate the theoretical value of the dynamic impact platform stress.

[0099] In one embodiment, in order to verify the accuracy of the evaluation results of the dynamic impact platform stress of the honeycomb structure, on the one hand, the simulation results of the dynamic impact platform stress at different real-time impact speeds under the finite element simulation experiment are recorded, and on the other hand, the evaluation results of the parameters of the finite element simulation experiment evaluated by the stress evaluation method of the honeycomb structure of the present invention are recorded and compared. The results are shown in Table 1.

[0100] Table 1 Simulation results and evaluation results of dynamic impact platform stress at different real-time impact speeds

[0101] Real-time impact speed (m / s) Simulation results (MPa) Evaluation results (MPa) error 1 0.51 0.57 +11.76％ 5 0.56 0.58 +3.58％ 10 0.59 0.59 0 20 0.65 0.62 -4.62％ 30 0.70 0.66 -5.71％ 50 0.79 0.76 -3.80％

[0102] From the comparison of the results in Table 1, it can be seen that the evaluation results are highly consistent with the simulation results, and the error is still low when the real-time impact velocity is very high, which further verifies the reliability of the stress evaluation method of the honeycomb structure of the present invention. The present invention can evaluate the dynamic impact platform stress of the honeycomb structure under different cell sizes, reveal the influence of size effect and inertia effect on the mechanical properties of the honeycomb structure, and provide an important reference for the energy absorption effect evaluation and performance-oriented design of the honeycomb structure.

[0103] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0104] In one embodiment, a stress evaluation device for a honeycomb structure is provided, and the stress evaluation device for the honeycomb structure corresponds one-to-one to the stress evaluation method for the honeycomb structure in the above embodiment. Figure 5 As shown, the stress evaluation device of the honeycomb structure includes a cell size factor processing module 10 and an impact platform stress determination module 20. The functional modules are described in detail as follows:

[0105] A cell size factor processing module 10 is used to obtain an evaluation request for a cell size factor of a honeycomb structure, and determine a relative structural density, a quasi-static failure stress, and a dynamic densification strain of the honeycomb structure according to the cell size factor;

[0106] The impact platform stress determination module 20 is used to determine the dynamic impact platform stress of the honeycomb structure according to the relative density of the structure, the quasi-static failure stress and the dynamic compaction strain, and obtain an evaluation result corresponding to the evaluation request according to the dynamic impact platform stress.

[0107] In one embodiment, the cell size factor processing module 10 includes:

[0108] A relative size determination unit, used for determining a relative wall length and a relative wall thickness of each cell according to the cell size factor;

[0109] The structural relative density determining unit is used to determine the structural relative density of the honeycomb structure according to the relative wall length dimension and the relative wall thickness dimension.

[0110] In one embodiment, the cell size factor processing module 10 further includes:

[0111] A preset relative density model processing unit is used to process the relative wall length dimension and the relative wall thickness dimension through a preset relative density model to obtain a relative density of the structure, wherein the preset relative density model includes:

[0112]

[0113] Among them, ρ r Indicates the relative density of the structure;

[0114] t / n represents the relative wall thickness;

[0115] l / n represents the relative wall length dimension;

[0116] n represents the cell size factor;

[0117] t represents the thickness of the cell wall;

[0118] l represents the length of the cell wall.

[0119] In one embodiment, the cell size factor processing module 10 further includes:

[0120] A material yield stress acquisition unit, used to acquire the material yield stress obtained by performing a quasi-static compression test on the honeycomb structure;

[0121] The quasi-static failure stress determination unit is used to determine the quasi-static failure stress according to the material yield stress, the relative wall length dimension and the relative wall thickness dimension.

[0122] In one embodiment, the cell size factor processing module 10 further includes:

[0123] A preset quasi-static stress model processing unit is used to process the material yield stress, the relative wall length dimension and the relative wall thickness dimension through a preset quasi-static stress model to obtain a quasi-static failure stress, wherein the preset quasi-static stress model includes:

[0124]

[0125] Where σ0 represents the quasi-static failure stress;

[0126] t / n represents the relative wall thickness;

[0127] l / n represents the relative wall length dimension;

[0128] n represents the cell size factor;

[0129] t represents the thickness of the cell wall;

[0130] l represents the length of the single cell wall;

[0131] σ ys Represents the material yield stress.

[0132] In one embodiment, the cell size factor processing module 10 further includes:

[0133] A real-time impact velocity acquisition unit, used to acquire the real-time impact velocity corresponding to the dynamic impact test of the honeycomb structure;

[0134] A critical impact velocity determination unit, used to determine a critical impact velocity according to the cell size factor;

[0135] The dynamic compaction strain determination unit is used to determine the dynamic compaction strain according to the real-time impact velocity, the critical impact velocity and the structural relative density.

[0136] In one embodiment, the cell size factor processing module 10 further includes:

[0137] A preset critical impact velocity model processing unit is used to obtain the structural material density and material yield stress of the honeycomb structure, and process the cell size factor, the structural material density and the material yield stress through a preset critical impact velocity model to obtain a critical impact velocity. The preset critical impact velocity model includes:

[0138]

[0139]

[0140] Among them, V w represents the critical impact velocity;

[0141] C represents the cell fitting coefficient;

[0142] ε ys Represents the material yield stress;

[0143] ρ s Indicates the density of structural materials;

[0144] C0 represents the basic fitting coefficient;

[0145] n represents the cell size factor.

[0146] In one embodiment, the cell size factor processing module 10 further includes:

[0147] A preset dynamic compaction strain model processing unit is used to process the real-time impact velocity, the critical impact velocity and the structural relative density through a preset dynamic compaction strain model to obtain a dynamic compaction strain corresponding to the real-time impact velocity, wherein the preset dynamic compaction strain model includes:

[0148]

[0149] Among them, ε d represents the dynamic compaction strain;

[0150] V0 represents the real-time impact velocity;

[0151] V w represents the critical impact velocity;

[0152] ρ r Represents the relative density of the structure.

[0153] In one embodiment, the impact platform stress determination module 20 includes:

[0154] A structural equivalent density determining unit, used for obtaining the structural material density of the honeycomb structure, and determining the structural equivalent density of the honeycomb structure according to the structural material density and the structural relative density;

[0155] The dynamic impact platform stress determination unit is used to determine the dynamic impact platform stress of the honeycomb structure according to the structural equivalent density, the real-time impact velocity, the quasi-static failure stress and the dynamic compaction strain.

[0156] In one embodiment, the impact platform stress determination module 20 further includes:

[0157] A preset dynamic impact stress model processing unit is used to process the structural equivalent density, the real-time impact velocity, the quasi-static failure stress and the dynamic compaction strain through a preset dynamic impact stress model to obtain a dynamic impact platform stress corresponding to the real-time impact velocity, wherein the preset dynamic impact stress model includes:

[0158]

[0159] Among them, σ p Represents dynamic impact stress;

[0160] σ0 represents the quasi-static failure stress;

[0161] ρ0 represents the structural equivalent density;

[0162] V0 represents the real-time impact velocity;

[0163] ε d represents the dynamic compaction strain.

[0164] The specific definition of the stress assessment device for the honeycomb structure can be found in the definition of the stress assessment method for the honeycomb structure above, which will not be repeated here. Each module in the above-mentioned stress assessment device for the honeycomb structure can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0165] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 6 As shown. The computer device includes a processor, a memory, a network interface and a database connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a readable storage medium and an internal memory. The readable storage medium stores an operating system, computer-readable instructions and a database. The internal memory provides an environment for the operation of the operating system and computer-readable instructions in the readable storage medium. The database of the computer device is used to store data involved in the stress assessment method of the cellular structure. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer-readable instructions are executed by the processor, a stress assessment method for the cellular structure is implemented. The readable storage medium provided in this embodiment includes a non-volatile readable storage medium and a volatile readable storage medium.

[0166] In one embodiment, a computer device is provided, including a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor, wherein the processor executes the computer-readable instructions to implement the following steps:

[0167] Obtaining an evaluation request including a cell size factor of a honeycomb structure, and determining a structural relative density, a quasi-static failure stress, and a dynamic densification strain of the honeycomb structure according to the cell size factor;

[0168] The dynamic impact platform stress of the honeycomb structure is determined according to the structural relative density, the quasi-static failure stress and the dynamic compaction strain, and an evaluation result corresponding to the evaluation request is obtained according to the dynamic impact platform stress.

[0169] In one embodiment, one or more computer-readable storage media storing computer-readable instructions are provided. The readable storage media provided in this embodiment include non-volatile readable storage media and volatile readable storage media. The readable storage media store computer-readable instructions, and when the computer-readable instructions are executed by one or more processors, the following steps are implemented:

[0170] Obtaining an evaluation request including a cell size factor of a honeycomb structure, and determining a structural relative density, a quasi-static failure stress, and a dynamic densification strain of the honeycomb structure according to the cell size factor;

[0171] The dynamic impact platform stress of the honeycomb structure is determined according to the structural relative density, the quasi-static failure stress and the dynamic compaction strain, and an evaluation result corresponding to the evaluation request is obtained according to the dynamic impact platform stress.

[0172] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware through computer-readable instructions. The computer-readable instructions can be stored in a non-volatile readable storage medium or a volatile readable storage medium. When the computer-readable instructions are executed, they can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0173] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0174] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A stress assessment method for a honeycomb structure, characterized in that: include: Obtaining an evaluation request including a cell size factor of a honeycomb structure, and determining a structural relative density, a quasi-static failure stress, and a dynamic densification strain of the honeycomb structure according to the cell size factor; The dynamic impact platform stress of the honeycomb structure is determined according to the structural relative density, the quasi-static failure stress and the dynamic compaction strain, and an evaluation result corresponding to the evaluation request is obtained according to the dynamic impact platform stress.

2. The stress evaluation method of a honeycomb structure according to claim 1, characterized in that: The determining the structural relative density of the honeycomb structure according to the cell size factor comprises: Determine the relative wall length and relative wall thickness of each cell according to the cell size factor; The relative structural density of the honeycomb structure is determined according to the relative wall length dimension and the relative wall thickness dimension.

3. The stress evaluation method of a honeycomb structure according to claim 2, characterized in that: The step of determining the relative structural density of the honeycomb structure according to the relative wall length and the relative wall thickness comprises: The relative wall length dimension and the relative wall thickness dimension are processed by a preset relative density model to obtain a relative density of the structure, wherein the preset relative density model includes: Among them, ρ r Indicates the relative density of the structure; t represents the cell wall thickness size corresponding to the relative wall thickness size; l represents the single cell wall length corresponding to the relative wall length.

4. The stress evaluation method of a honeycomb structure according to claim 2, characterized in that: The determining of the quasi-static failure stress according to the cell size factor comprises: Obtaining a material yield stress obtained by performing a quasi-static compression test on the honeycomb structure; A quasi-static failure stress is determined based on the material yield stress, the relative wall length dimension, and the relative wall thickness dimension.

5. The stress evaluation method of a honeycomb structure according to claim 4, characterized in that: The determining of the quasi-static failure stress according to the material yield stress, the relative wall length dimension and the relative wall thickness dimension comprises: The material yield stress, the relative wall length dimension and the relative wall thickness dimension are processed by a preset quasi-static stress model to obtain a quasi-static failure stress, wherein the preset quasi-static stress model includes: Where σ0 represents the quasi-static failure stress; t represents the cell wall thickness size corresponding to the relative wall thickness size; l represents the single cell wall length corresponding to the relative wall length; σ ys Represents the material yield stress.

6. The stress evaluation method of a honeycomb structure according to claim 2, characterized in that: The determining of the dynamic densification strain according to the cell size factor comprises: Obtaining a real-time impact velocity corresponding to a dynamic impact test on the honeycomb structure; determining a critical impact velocity according to the cell size factor; The dynamic compaction strain is determined according to the real-time impact velocity, the critical impact velocity and the structural relative density.

7. The stress evaluation method of a honeycomb structure according to claim 6, characterized in that: The determining of the critical impact velocity according to the cell size factor comprises: The structural material density and material yield stress of the honeycomb structure are obtained, and the cell size factor, the structural material density and the material yield stress are processed by a preset critical impact velocity model to obtain a critical impact velocity. The preset critical impact velocity model includes: Where V represents the critical impact velocity; C represents the cell fitting coefficient; σ ys Represents the material yield stress; ρ s Indicates the density of structural materials; C0 represents the basic fitting coefficient; n represents the cell size factor.

8. The stress evaluation method of a honeycomb structure according to claim 6, characterized in that: The determining of the dynamic compaction strain according to the real-time impact velocity, the critical impact velocity and the structural relative density comprises: The real-time impact velocity, the critical impact velocity and the structural relative density are processed by a preset dynamic compaction strain model to obtain a dynamic compaction strain corresponding to the real-time impact velocity, wherein the preset dynamic compaction strain model includes: Among them, ε d represents the dynamic compaction strain; V0 represents the real-time impact velocity; V w represents the critical impact velocity; ρ r Represents the relative density of the structure.

9. The stress evaluation method of a honeycomb structure according to claim 6, characterized in that: The step of determining the dynamic impact platform stress of the honeycomb structure according to the relative density of the structure, the quasi-static failure stress and the dynamic compaction strain comprises: Acquire the structural material density of the honeycomb structure, and determine the structural equivalent density of the honeycomb structure according to the structural material density and the structural relative density; The dynamic impact platform stress of the honeycomb structure is determined according to the structural equivalent density, the real-time impact velocity, the quasi-static failure stress and the dynamic compaction strain.

10. The stress evaluation method of a honeycomb structure according to claim 6, characterized in that: The step of determining the dynamic impact platform stress of the honeycomb structure according to the structural equivalent density, the real-time impact velocity, the quasi-static failure stress and the dynamic compaction strain comprises: The structural equivalent density, the real-time impact velocity, the quasi-static failure stress and the dynamic compaction strain are processed by a preset dynamic impact stress model to obtain a dynamic impact platform stress corresponding to the real-time impact velocity, wherein the preset dynamic impact stress model includes: Among them, σ p Represents dynamic impact stress; σ0 represents the quasi-static failure stress; ρ0 represents the structural equivalent density; V0 represents the real-time impact velocity; ε d represents the dynamic compaction strain.

11. A stress evaluation device for a honeycomb structure, characterized in that: include: A cell size factor processing module, used to obtain an evaluation request for a cell size factor of a honeycomb structure, and determine a relative structural density, a quasi-static failure stress, and a dynamic densification strain of the honeycomb structure according to the cell size factor; An impact platform stress determination module is used to determine the dynamic impact platform stress of the honeycomb structure according to the relative density of the structure, the quasi-static failure stress and the dynamic compaction strain, and obtain an evaluation result corresponding to the evaluation request according to the dynamic impact platform stress.

12. A computer device comprising a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor, characterized in that: When the processor executes the computer-readable instructions, the stress evaluation method for the honeycomb structure according to any one of claims 1 to 10 is implemented.

13. A computer-readable storage medium storing computer-readable instructions, characterized in that: When the computer readable instructions are executed by one or more processors, the one or more processors are caused to perform the stress assessment method for a honeycomb structure according to any one of claims 1 to 10 .

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