New energy automobile high-voltage wiring harness collision thermal failure performance test and calibration method

Abstract

The invention relates to the technical field of materials, and discloses a new energy automobile high-voltage wiring harness collision thermal failure performance test and calibration method, which comprises the steps of selecting an equivalent model to construct a wiring harness body according to geometric scale characteristics of a high-voltage wiring harness; based on the type of the equivalent model, designing a test matrix and performing a test to obtain force-displacement data and stress-strain data under quasi-static and dynamic conditions; through finite element simulation benchmarking data, optimizing a stress-strain relation and material parameters, and determining a constitutive model of the material; according to actual working condition characteristics, performing a wire harness dynamic and static damage test, and verifying and optimizing the constitutive model; and according to the actual working condition characteristics, performing a wire harness dynamic and static limit test to obtain a material fracture failure criterion. According to the method, the equivalent material model of the wire harness is inversed in a test and simulation benchmarking mode on the basis of the geometric dimension and integration characteristics of the high-voltage wire harness, and possible damage or short-circuit failure of the wire harness in the collision process is accurately represented.

Description

Technical Field

[0001] The present invention relates to the field of material technology, and in particular to a method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness of a new energy vehicle. Background Art

[0002] Electrification has been a major trend in automotive technology development in recent years. Compared to traditional fuel-powered vehicles, electric vehicles utilize electricity as their driving force, replacing the engine with a high-voltage electrical system. This system consists of a high-voltage wiring harness, power distribution system, and charging system. In a collision, deformation of internal components inevitably intrudes into the high-voltage wiring harness, causing deformation and failure, leading to powertrain failure, short circuits, and even fires and explosions. Therefore, collision-induced thermal failure of the high-voltage wiring harness cannot be ignored during vehicle passive safety development.

[0003] The failure behavior of materials or parts can be predicted through simulation analysis, and material failure criteria are a prerequisite for accurate prediction. (CN11060396A) discloses a method for calibrating the mechanical behavior of non-metallic materials. This method proposes biaxial tension, shear, compression, and tension test conditions for regular, homogeneous plastic materials, and clarifies the calibration sequence and rules for each condition during the simulation calibration phase. (CN111125960A) discloses a method for optimizing the parameters of a GISSMO material failure model. This method performs parameterized optimization on the failure model of homogeneous materials.

[0004] The aforementioned methods are suitable for characterizing the mechanical behavior of homogeneous plastic materials and fracture failure of homogeneous materials, respectively. However, they are not suitable for materials such as high-voltage wiring harnesses, which have heterogeneous properties and complex geometric structures. Accurately characterizing the mechanical behavior of high-voltage wiring harnesses and developing effective failure criteria are currently a pressing issue. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention proposes a method for testing and calibrating the collision thermal failure performance of high-voltage wire harnesses of new energy vehicles to solve the above technical problems.

[0006] A method for testing and calibrating the collision thermal failure performance of high-voltage wiring harnesses for new energy vehicles, comprising:

[0007] According to the geometric scale characteristics of the high-voltage wire harness, an equivalent model is selected to construct the wire harness body;

[0008] Based on the type of equivalent model, a test matrix is ​​designed and tested to obtain force-displacement data and stress-strain data under quasi-static and dynamic conditions;

[0009] Benchmarking the force-displacement data and stress-strain data through finite element simulation, optimizing the stress-strain relationship and material parameters, and determining the constitutive model of the material;

[0010] According to the actual working conditions, dynamic and static destruction tests of the wiring harness are carried out to verify and optimize the constitutive model;

[0011] According to the actual working conditions, dynamic and static limit tests of the wiring harness are carried out to obtain the material fracture failure criteria.

[0012] Furthermore, the equivalent model includes a univariate equivalent model and a bivariate equivalent model;

[0013] The univariate equivalent model is a homogeneous solid model constructed based on the overall characteristics of the wiring harness body;

[0014] The binary equivalent model is a heterogeneous model constructed in layers based on the structural features of the inner and outer layers of the wiring harness body.

[0015] Furthermore, the outer layer structure of the binary equivalent model is characterized by a hyperelastic material model, and the inner layer structure is characterized by an elastic-plastic material model.

[0016] Furthermore, the test matrix includes tension, compression or tension and compression combined loading tests, and the tests cover quasi-static and dynamic loading conditions.

[0017] Furthermore, when benchmarking through the finite element simulation, a multi-objective optimization tool is used to optimize the parameters of the constitutive model with the goal of minimizing the error between the test and simulation force-displacement curves.

[0018] Furthermore, the dynamic and static destructive tests include quasi-static compression, quasi-static tension, dynamic compression and dynamic tension conditions.

[0019] Furthermore, the limit test uses a sharp-angled indenter to compress and load the wiring harness body, and determines the moment of failure by detecting the formation of a path in real time.

[0020] Furthermore, the pointed indenter is connected to the inner conductor of the wiring harness body through a wire. When the outer structure of the wiring harness body is penetrated and fails by the pointed indenter, the pointed indenter contacts the inner conductor of the wiring harness body to form a path.

[0021] Furthermore, the failure criterion is constructed based on the cumulative damage criterion, and the damage criterion parameters are inversely optimized by minimizing the failure displacement error of experiments and simulations.

[0022] Furthermore, it also includes:

[0023] By comparing the test data with the finite element simulation results, the wiring harness material card for collision failure analysis is obtained.

[0024] The invention adopting the above technical solution has the following advantages:

[0025] Based on the geometric scale and integrated characteristics of high-voltage wiring harnesses, the present invention inverts the equivalent material model of the wiring harness through experiments and simulation benchmarking, accurately characterizes the possible damage or short-circuit failure of the wiring harness during a collision, and provides accurate material cards for collision failure analysis of wiring harnesses for new energy vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the specific embodiments. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0027] Figure 1 This is a flow chart of a method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness for a new energy vehicle according to the present invention;

[0028] Figure 2 This is a schematic diagram of the geometry and equivalent model of the unitary structure of the wiring harness in a method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness for a new energy vehicle according to the present invention.

[0029] Figure 3 This is a schematic diagram of the geometry and equivalent model of the binary structure of the wiring harness in a new energy vehicle high-voltage wiring harness collision thermal failure performance test and calibration method according to the present invention.

[0030] Figure 4 This is a schematic diagram of a wiring harness device in a method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness for a new energy vehicle according to the present invention;

[0031] Figure 5 This is a schematic diagram of the failure displacement error and the fitting degree of the force-displacement curve in the collision thermal failure performance test and calibration method of the high-voltage wiring harness of a new energy vehicle in the present invention. Figure 1 ;

[0032] Figure 6 This is a schematic diagram of the failure displacement error and the fitting degree of the force-displacement curve in the collision thermal failure performance test and calibration method of the high-voltage wiring harness of a new energy vehicle in the present invention. Figure 2 。

[0033] Reference numerals:

[0034] 1. Wire harness; 2. Test device; 3. Wire; 4. High-sensitivity resistance variable meter; 5. High-speed camera. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0036] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0037] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0038] like Figures 1 to 6 As shown, the present invention provides a method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness for a new energy vehicle, comprising:

[0039] Step S01: Select an equivalent model to construct the wiring harness body 1 according to the geometric scale characteristics of the high-voltage wiring harness;

[0040] Step S02: Based on the type of equivalent model, design a test matrix and conduct tests to obtain force-displacement data and stress-strain data under quasi-static and dynamic conditions;

[0041] Step S03: aligning force-displacement data and stress-strain data through finite element simulation, optimizing stress-strain relationship and material parameters, and determining the constitutive model of the material;

[0042] Step S04: Conduct dynamic and static destructive tests on the wiring harness according to actual working conditions to verify and optimize the constitutive model;

[0043] Step S05: Conduct dynamic and static limit tests on the wiring harness according to actual working condition characteristics to obtain material fracture failure criteria.

[0044] In this embodiment, the equivalent model includes a univariate equivalent model and a bivariate equivalent model;

[0045] The univariate equivalent model is a homogeneous solid model constructed based on the overall characteristics of the harness body 1;

[0046] The binary equivalent model is a heterogeneous model constructed hierarchically based on the structural characteristics of the inner and outer layers of the harness body 1 .

[0047] Specifically, the one-dimensional equivalent model does not consider the hierarchical structure and material differences of the harness. It is used for the discretization of a single harness with a diameter less than 6mm. The harness model is constructed using solid elements with a unit size of 1mm to 3mm. The two-dimensional equivalent model includes a double-layer structure of inner and outer layers. The unit and material properties are independently decomposed according to the harness hierarchy. It is used for the finite element model construction of a single harness or integrated harness with a diameter greater than 6mm. In the construction of the two-dimensional equivalent model, the structure and size of the outer layer unit are key.

[0048] In this embodiment, the outer layer structure of the binary equivalent model is represented by a hyperelastic material model, and the inner layer structure is represented by an elastic-plastic material model.

[0049] In this embodiment, the test matrix includes tension, compression, or tension and compression combined loading tests, and the tests cover quasi-static and dynamic loading conditions.

[0050] In this embodiment, when benchmarking is performed through finite element simulation, a multi-objective optimization tool is used to optimize the parameters of the constitutive model with the goal of minimizing the error between the test and simulation force-displacement curves.

[0051] Specifically, the constitutive relationship calibration process is carried out in the order of quasi-static test and dynamic test. For the one-dimensional equivalent model, the elastic-plastic material model is directly used for calibration.

[0052] In the binary equivalent model, the mechanical behavior of the outer layer structure is described by the Mooney-Rivlin model or the OGDEN model, and the inner layer structure material is described by the elastic-plastic material model.

[0053] In this embodiment, the dynamic and static destructive tests include quasi-static compression, quasi-static tension, dynamic compression, and dynamic tension conditions.

[0054] Specifically, during the constitutive relationship optimization process, the actual working condition characteristics are taken into consideration to conduct dynamic and static tests on the wiring harness body 1. The test conditions include quasi-static compression of the wiring harness, quasi-static stretching of the wiring harness, dynamic compression of the wiring harness, and dynamic stretching of the wiring harness.

[0055] Dynamic tests are typically conducted at two or three strain rates within the range of 1 / s to 200 / s. Displacement-load data is obtained from these tests and used for finite element simulation benchmarking and constitutive relationship optimization.

[0056] Taking the minimum error of the displacement-load curve of the quasi-static wire harness body 1 test and simulation as the optimization target under quasi-static conditions, the stress-strain relationship or model parameters in the material constitutive relationship are optimized based on the multi-objective optimization tool; taking the minimum error of the displacement-load curve of the dynamic wire harness body 1 test and simulation as the optimization target under dynamic conditions, the strain rate effect parameters in the material constitutive relationship are optimized based on the multi-objective optimization tool.

[0057] In this embodiment, the limit test uses a sharp-angle indenter to compress and load the wiring harness body 1, and determines the moment of failure by detecting the formation of a path in real time.

[0058] In this embodiment, the pointed indenter is connected to the inner conductor of the wiring harness body 1 through the wire 3. When the outer structure of the wiring harness body 1 is penetrated and fails by the pointed indenter, the pointed indenter contacts the inner conductor of the wiring harness body 1 to form a path.

[0059] In this embodiment, the failure criterion is constructed based on the cumulative damage criterion, and the damage criterion parameters are inversely optimized by minimizing the failure displacement error between experiments and simulations.

[0060] Specifically, during the failure criterion construction process, actual working conditions are taken into account, and dynamic and static limit tests of the wiring harness are conducted to obtain material fracture failure criteria. The purpose of the limit test is to obtain the failure of the wiring harness body 1, confirm the failure moment, and obtain process data for reverse calibration.

[0061] In the process of constructing the failure criterion, the limit test aims to destroy the outer material of the wiring harness. An extreme sharp-angle indenter is used as the test device 2 to perform the compression test, and the sharp angle range is 30° to 90°.

[0062] During the failure criteria construction process, test device 2 is made of metal. Before the test, test device 2 is connected to the inner metal layer of the wiring harness via wire 3. The outer layer of the test material prevents the test device 2 from forming a path between the test device 2 and the inner metal layer of the wiring harness. When the wiring harness fails, test device 2 penetrates the outer layer and contacts the inner metal layer of the wiring harness, forming a path between the test device 2 and the inner metal layer of the wiring harness.

[0063] In the process of constructing the failure criterion, the test failure moment is detected by a high-sensitivity resistance change meter 4, and the path formation moment is recorded by a high-speed camera device 5.

[0064] During the failure criterion construction process, the failure displacement corresponding to the moment of failure and the experimental displacement-load data were obtained through experiments for finite element simulation benchmarking and constitutive relationship optimization. A cumulative damage criterion based on stress state and strain rate was used as the failure criterion. The quasi-static test and simulation displacement-load curves of the harness body 1 and the minimum error in the failure displacement were used as the optimization objectives under quasi-static conditions. The damage criterion was inversely optimized using a multi-objective optimization tool. The dynamic test and simulation displacement-load curves of the harness body 1 and the minimum error in the failure displacement were used as the optimization objectives under dynamic conditions. The strain rate effect parameters in the damage criterion were optimized using a multi-objective optimization tool.

[0065] In this embodiment, it also includes:

[0066] By comparing the test data with the finite element simulation results, the wiring harness material card for collision failure analysis is obtained. Specific embodiment one:

[0068] A high-voltage wiring harness (one-dimensional equivalent model)

[0069] like Figure 1 As shown, the diameter of the high-voltage wire harness in Example 1 is 5 mm, including the surface adhesive layer and the internal copper wire core layer. The overall diameter of the wire harness is 5 mm. A unitary structural model is selected based on its size characteristics.

[0070] The second step is the test design. The unitary structure does not consider the hierarchical structure and material differences of the harness, and directly conducts the overall test of the harness. The test matrix includes cylindrical static pressure and dynamic impact tests. To ensure the consistency of the test and the validity of the data, 3-5 tests are carried out for each working condition. The data obtained from the test include force-displacement data and test videos. Then, the discrete data points collected in the test are preprocessed to obtain the corresponding theoretical engineering stress and strain data of the static test. The calculation formula is as follows

[0071]

[0072] Where ε is the engineering strain, σ is the engineering stress, δ is the displacement, L0 is the length of the two points before the force is applied, F is the force, and A is the original cross-sectional area.

[0073] Then, the true stress-strain data was obtained based on the obtained theoretical engineering stress-strain data using the following formula.

[0074] ε T =ln(1+ε),σ T =σ(1+ε)

[0075] Among them, ε T is the true strain, σ T is the true stress.

[0076] In the third step, the true stress and strain data obtained in step 2 are substituted into the finite element simulation model. A finite element simulation calibration model is established based on each test condition. The boundary conditions and load application method are configured according to the test conditions in step 2 to form an initial calibration model. Material model optimization is performed based on the comparison of the simulation results of the initial calibration model with the test results.

[0077] The specific steps are as follows:

[0078] 1. Preliminary curve fitting. Use the least squares third-order polynomial to fit the true stress-strain curve obtained in step 2, and the curve equation is as follows:

[0079] σ(ε)=A0+B0ε+C0ε 2 +D0ε 3

[0080] Among them, the polynomial coefficients A0, B0, C0, and D0 are known values, and ε is the strain.

[0081] 2. Set the optimization target. Set the root mean square error (RMSE) of the simulated force-displacement and the test force-displacement under two working conditions as the optimization target, which is defined as:

[0082]

[0083] Among them, F sim and F exp are the simulation force value and the test force value respectively, and N is the number of displacement sampling points.

[0084] 3. Set the initial value. Set the initial temperature T k =1000, the initial values ​​of the optimization parameters are the coefficients A0, B0, C0, D0 obtained by least squares fitting in step 1, and the iteration number accumulator k is set to 0.

[0085] 4. Enter temperature iteration. Determine whether the current temperature is greater than 100. If so, it is considered a high temperature stage and proceed to step 4.1; otherwise, it is a low temperature stage and proceed to step 4.2.

[0086] 4.1 High temperature stage. Gaussian perturbation is used to generate new solutions, and Latin hypercube sampling is used to generate the numerical population in each iteration, which is defined as:

[0087]

[0088] in Achieve temperature-related disturbance amplitude attenuation.

[0089] 4.2 Low temperature stage. Using the quasi-Newton method, the gradient direction is approximately calculated using the Hessian matrix. The formula is:

[0090]

[0091] Where H is the Hessian matrix of the objective function.

[0092] 5. Calculate the number of parameter iterations at each temperature. Set the iteration parameter accumulator c = 0 at a single temperature. Calculate the number of iterations L based on the Markov chain length adaptive mechanism. k , the initial chain length L0 is 50, the number of iterations is dynamically adjusted with the temperature, and the calculation formula is:

[0093] L k =[L0·(1+log(T k / T0))]

[0094] 6. Iteratively optimize the parameters. Select a new solution from the population generated in step 4 and use the Metropolis criterion to determine the acceptance probability. Then delete the selected new solution from the population. The Metropolis criterion is as follows:

[0095]

[0096] Among them, α is the adaptive attenuation coefficient, and △E is the difference between the objective function value F(a) of the new solution and the current solution.

[0097] Generate a random number between 0 and 1 and compare it with P. If the random number is less than P, accept the new solution; otherwise, reject the new solution. Set c = c + 1.

[0098] Repeat the iteration. Repeat step 6 until c is greater than or equal to L k .

[0099] Update parameters. k=k+1,

[0100] Repeat the temperature iteration. Return to step 4 until k is greater than or equal to 500 or T k Less than 10 -5 .

[0101] Complete the optimization and get the ideal parameters.

[0102] The fourth step is to carry out an extreme test, using a 60° sharp-angle indenter to carry out a wire harness extrusion test. To ensure the consistency of the test and the validity of the data, 3-5 tests are carried out for each working condition. The data obtained from the test include force-displacement data, failure time and test video. A CAE simulation calibration model is established according to the extreme test conditions, and the optimized material constitutive model obtained in step three is used for simulation to obtain simulation results without substituting failure parameters. The simulation results are analyzed to obtain the stress state and critical strain of the material under quasi-static and dynamic conditions. The GISSMO fracture module is used to obtain the stress triaxiality and equivalent strain based on the constructed CAE simulation model. As the initial point of the fracture curve (stress triaxiality-fracture strain curve), simulation calibration of the failure section is carried out, and surface mesh deletion is used as the failure criterion.

[0103] Specifically, the fracture curves were inverted based on three working conditions: static cylindrical extrusion, dynamic cylindrical extrusion, and 60° sharp angle extrusion test. The goal was to achieve a fitting degree of more than 85% between the failure displacement error and the force-displacement curve (see Figure 5 ), at this time the mechanical properties calibration of a certain wiring harness material (unitary structure) is completed.

[0104] In step 2, the processing flow of a certain wire harness compression test data is as follows: First, the material compression test requires the use of an electronic universal testing machine, which can accurately test the quasi-static mechanical properties of the material, obtain the test load data of the wire harness when it is squeezed, and convert it into theoretical stress and strain (theoretical strain = displacement / wire harness diameter, theoretical stress = force / wire harness cross-sectional area).

[0105] In step 4, the limit test requires using a high-sensitivity resistance change meter 4 to connect the positive and negative poles of the conductor in the wiring harness and the hammer head respectively. When the conductor comes into contact with the hammer head, a path is formed between the conductor-high-sensitivity resistance change meter 4-hammer head. The high-sensitivity resistance change meter 4 displays data, and the moment when the path is formed, that is, the moment of failure, is recorded by the high-speed camera device 5. Specific embodiment two:

[0107] A high-voltage wiring harness (binary equivalent model)

[0108] As in the example, follow Figure 1 The calibration is performed according to the steps shown. The first step is to determine the type of equivalent model to be established. In Example 2, the diameter of the high-voltage wire harness is 8.8 mm, including a surface adhesive layer and an internal copper wire core layer. The internal wire core diameter is 6 mm. A binary structure model is selected based on its size characteristics.

[0109] The second step is the experimental design. The binary equivalent model needs to consider the inner and outer double-layer structures separately. Experimental design needs to be carried out for the surface adhesive layer, the internal copper wire core layer, and the entire wiring harness. Therefore, the test matrix includes static tension and static compression of the surface adhesive layer and static compression tests of the cylindrical and wedge surfaces of the entire wire core. To ensure the consistency of the test and the validity of the data, 3-5 tests are carried out for each working condition to obtain the experimental data of the inner and outer layer materials of a certain wiring harness (including force-displacement curves and experimental videos). By processing the experimental data, the basic material properties and engineering stress-strain curves of the inner and outer layer materials are obtained, and then converted into true stress-strain curves. The specific operation is consistent with Example 1.

[0110] In the third step, the stress-strain curves obtained in step 2 are substituted into the finite element simulation model. A CAE simulation calibration model is established based on each test condition. Boundary and loading conditions are established based on the test conditions in step 2 to form an initial calibration model. Material model optimization is performed based on a comparison of the simulation results of the initial calibration model with the test results.

[0111] Specifically, the Mooney-Rivlin model will be used to characterize the material properties of the surface rubber layer. The parameters of the Mooney-Rivlin model will be calculated using the stress-strain curve obtained in step 2. The stress-strain curve of the inner layer material will be substituted into the finite element model. The subsequent debugging method is the same as step 3 of Example 1. The formula of the Mooney-Rivlin model is:

[0112]

[0113] in, σ is the strain ε i The corresponding stress, C 10 and C 01 are model parameters.

[0114] The fourth step is to conduct dynamic and static tests on the wiring harness, including static and dynamic cylindrical extrusion tests. Each working condition is carried out 3-5 times to obtain the force-displacement curves and test videos for each working condition of the wiring harness. A CAE simulation calibration model is established based on the test conditions. The stress-strain curves obtained in step 2 are substituted into the finite element simulation model. Boundary conditions and loading conditions are established based on the dynamic and static test conditions of the wiring harness to form an initial calibration model. Based on the comparison of the initial calibration results with the test results, the material model is optimized.

[0115] Specifically, it is consistent with step 3 of Example 1.

[0116] The fifth step is to conduct an extreme test, using a 60° sharp-angle indenter to perform a wire harness extrusion test. To ensure the consistency of the test and the validity of the data, 3-5 tests are carried out under each working condition.

[0117] The data obtained from the test includes force-displacement data, failure time, and test video. A CAE simulation calibration model was established based on the extreme test conditions. The optimized material constitutive model obtained in step 3 was used for simulation to obtain simulation results without incorporating failure parameters.

[0118] The simulation results were analyzed to obtain the stress state and critical strain of the material under quasi-static and dynamic conditions. The stress triaxiality and equivalent strain were obtained based on the constructed CAE simulation model. These were used as the initial points of the fracture curve (stress triaxiality-fracture strain curve). Simulation calibration of the failure section was carried out, and the failure criterion was that the outer adhesive layer mesh was deleted to expose the internal core mesh.

[0119] Specifically, the goal is to achieve a fitting degree of more than 85% between the failure displacement error and the force-displacement curve (see Figure 6 ), at this time the mechanical properties calibration of a certain wiring harness material (binary structure) is completed.

[0120] The above embodiments 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 they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A method for testing and calibrating the collision thermal failure performance of high-voltage wiring harnesses of new energy vehicles, characterized in that: include: According to the geometric scale characteristics of the high-voltage wire harness, an equivalent model is selected to construct the wire harness body; Based on the type of equivalent model, a test matrix is ​​designed and tested to obtain force-displacement data and stress-strain data under quasi-static and dynamic conditions; Benchmarking the force-displacement data and stress-strain data through finite element simulation, optimizing the stress-strain relationship and material parameters, and determining the constitutive model of the material; According to the actual working conditions, dynamic and static destruction tests of the wiring harness are carried out to verify and optimize the constitutive model; According to the actual working conditions, dynamic and static limit tests of the wiring harness are carried out to obtain the material fracture failure criteria.

2. A new energy vehicle high-voltage wiring harness collision thermal failure performance testing and calibration method according to claim 1, characterized in that: The equivalent model includes a univariate equivalent model and a bivariate equivalent model; The univariate equivalent model is a homogeneous solid model constructed based on the overall characteristics of the wiring harness body; The binary equivalent model is a heterogeneous model constructed in layers based on the structural features of the inner and outer layers of the wiring harness body.

3. A new energy vehicle high-voltage wiring harness collision thermal failure performance testing and calibration method according to claim 2, characterized in that: The outer layer structure of the binary equivalent model is characterized by a hyperelastic material model, and the inner layer structure is characterized by an elastic-plastic material model.

4. A new energy vehicle high-voltage wiring harness collision thermal failure performance testing and calibration method according to claim 1, characterized in that: The test matrix includes tension, compression or combined tension and compression loading tests, and the tests cover quasi-static and dynamic loading conditions.

5. The method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness of a new energy vehicle according to claim 1 is characterized in that: When benchmarking through the finite element simulation, a multi-objective optimization tool is used to optimize the parameters of the constitutive model with the goal of minimizing the error between the test and simulation force-displacement curves.

6. A new energy vehicle high-voltage wiring harness collision thermal failure performance testing and calibration method according to claim 1, characterized in that: The dynamic and static destructive tests include quasi-static compression, quasi-static tension, dynamic compression and dynamic tension conditions.

7. The method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness of a new energy vehicle according to claim 1 is characterized in that: The limit test uses a sharp-angled indenter to compress and load the wiring harness body, and determines the moment of failure by detecting the formation of a path in real time.

8. A method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness of a new energy vehicle according to claim 7, characterized in that: The pointed indenter is connected to the inner conductor of the wiring harness body through a wire. When the outer structure of the wiring harness body is penetrated and fails by the pointed indenter, the pointed indenter contacts the inner conductor of the wiring harness body to form a path.

9. The method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness of a new energy vehicle according to claim 1, characterized in that: The failure criterion is constructed based on the cumulative damage criterion, and the damage criterion parameters are inversely optimized by minimizing the failure displacement error between experiments and simulations.

10. The method for testing and calibrating the collision thermal failure performance of a high-voltage wiring harness of a new energy vehicle according to claim 1, characterized in that: Also includes: By comparing the test data with the finite element simulation results, the wiring harness material card for collision failure analysis is obtained.

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