Simulation test method of vehicle, electronic equipment and storage medium

Abstract

The invention provides a simulation test method of a vehicle, electronic equipment and a storage medium, the method is applied to the field of vehicles, and the method comprises the following steps: under the condition that a vehicle wire harness and a wire harness terminal are selected, performing three-dimensional modeling on a bonding structure of the wire harness terminal to obtain a three-dimensional simulation model; setting simulation parameters of the three-dimensional simulation model in simulation software; running simulation software according to the simulation parameters to obtain a simulation result of the three-dimensional simulation model; according to the simulation result, the maximum allowable current of the current bonding structure at the preset highest temperature is determined; according to the maximum permissible current, whether the actual current-carrying capacity of the bonding structure meets the power utilization requirement of the power utilization part or not is judged; and if not, adjusting the ground structure, and performing simulation verification again based on the adjusted ground structure until the actual current-carrying capability of the adjusted ground structure meets the power demand. According to the method, the risk of high-temperature fire caused by insufficient current-carrying capacity of the ground structure can be avoided, and the vehicle safety is improved.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically, to a simulation test method, electronic device and storage medium for a vehicle in the field of vehicles. Background Art

[0002] Single-wire design is often used in automotive electrical circuit design. This single-wire design can be understood as: the vehicle's power-consuming components only have a positive circuit, and the negative circuit returns power to the negative electrode of the battery by grounding the vehicle body. In the selection process of vehicle wiring harnesses, usually only the corresponding specifications of wiring harnesses are selected based on the different power of power-consuming components. However, selecting wiring harnesses based solely on this method may still lead to the risk of high-temperature fires during actual vehicle use, affecting vehicle safety. Summary of the invention

[0003] The present application provides a vehicle simulation test method, electronic equipment and storage medium, which can avoid the risk of high-temperature fire caused by insufficient current-carrying capacity of the grounding structure and improve vehicle safety.

[0004] In a first aspect, a vehicle simulation test method is provided, the method comprising: after selecting a vehicle wiring harness and a wiring harness terminal of the vehicle wiring harness, three-dimensionally modeling a grounding structure of the wiring harness terminal to obtain a three-dimensional simulation model of the grounding structure; setting simulation parameters of the three-dimensional simulation model in simulation software; running the simulation software according to the simulation parameters to obtain simulation results of the three-dimensional simulation model; determining a maximum allowable current of the current grounding structure at a preset maximum temperature according to the simulation results; judging whether an actual current-carrying capacity of the grounding structure meets the power demand of electrical components according to the maximum allowable current; if not, adjusting the grounding structure, and performing simulation verification again based on the adjusted grounding structure until the actual current-carrying capacity of the adjusted grounding structure meets the power demand.

[0005] The above technical solution, after selecting the vehicle wiring harness and wiring harness terminals, further adds the simulation of the grounding structure. Through the simulation of the grounding structure, the electrical-thermal conversion of the grounding structure is also taken into account in the vehicle wiring harness design process. Therefore, the risk of high-temperature fire caused by insufficient current-carrying capacity of the grounding structure can be effectively identified through simulation analysis in the simulation stage. When the actual current-carrying capacity of the grounding structure does not meet the power demand of the electrical components, it means that the actual current-carrying capacity of the grounding structure is insufficient. By further adjusting the grounding structure and simulating and verifying the adjusted grounding structure again until the actual current-carrying capacity of the adjusted grounding structure meets the above power demand, the risk of high-temperature fire caused by insufficient current-carrying capacity of the grounding structure during the subsequent actual use of the vehicle can be effectively avoided. By adding simulation analysis of the grounding structure, the safety and reliability of the grounding structure can be ensured when the vehicle wiring harness and wiring harness terminals are selected, the overall performance of the vehicle wiring harness can be improved, and the risk of fire in the vehicle can be reduced.

[0006] In combination with the first aspect, in some possible implementations, the simulation results include: the maximum temperature of the grounding components in the grounding structure under different currents; determining the maximum allowable current of the current grounding structure at a preset maximum temperature based on the simulation results, including: performing curve fitting to obtain a curve equation corresponding to the grounding components based on the maximum temperature of the grounding components in the grounding structure under different currents; wherein the curve equation characterizes the relationship between the maximum temperature and current of the grounding components; substituting the preset maximum temperature into the curve equation to calculate the maximum allowable current of the current grounding structure at the preset maximum temperature.

[0007] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, judging whether the actual current-carrying capacity of the grounding structure meets the power demand of the electrical components based on the maximum allowable current includes: determining the actual demand current of the electrical components; if the actual demand current is less than or equal to the maximum allowable current, judging that the actual current-carrying capacity of the grounding structure meets the power demand of the electrical components; if the actual demand current is greater than the maximum allowable current, judging that the actual current-carrying capacity of the grounding structure does not meet the power demand of the electrical components.

[0008] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the adjusting of the grounding structure includes: determining the target grounding component to be adjusted in the grounding structure; replacing the material of the target grounding component to reduce the resistivity of the target grounding component; and / or increasing the conductive area of ​​the target grounding component.

[0009] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the grounding components in the grounding structure include: welding nuts and body sheet metal; the grounding structure of the wiring harness terminal is three-dimensionally modeled to obtain a three-dimensional simulation model of the grounding structure, including: taking the center position of the through hole of the body sheet metal welded by the welding nut as the coordinate origin, taking the first direction as the x-axis direction, the second direction as the y-axis direction, and the third direction as the z-axis direction to establish a three-dimensional coordinate system; based on the three-dimensional coordinate system, importing the grounding components in the grounding structure to obtain a three-dimensional simulation model of the grounding structure.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the simulation parameters of the three-dimensional simulation model are set in the simulation software, including: setting the first type of simulation parameters and the second type of simulation parameters of the three-dimensional simulation model in the simulation software; wherein, the first type of simulation parameters include: general simulation parameters preliminarily set for the three-dimensional simulation model; the second type of simulation parameters include: target attribute parameters set for each grounding component in the three-dimensional simulation model, the target attribute parameters include attribute parameters related to heat generation and attribute parameters related to heat dissipation.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the simulation software is run according to the simulation parameters to obtain simulation data of the three-dimensional simulation model, including: determining the calculation domain of the three-dimensional simulation model; globally gridding the calculation domain to obtain a globally gridded calculation domain; locally grid refining the globally gridded calculation domain to obtain a locally grid refined calculation domain; setting a simulation calculation target in the simulation process according to the locally grid refined calculation domain; running the simulation software according to the simulation parameters, and performing simulation calculations according to the simulation calculation targets during the running of the simulation software to obtain simulation data of the three-dimensional simulation model.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the grounding components in the three-dimensional simulation model include: a bolt body and a welding nut, and the simulation calculation target includes: a simulation calculation completion target; the simulation calculation completion target is used to describe the solution completion condition of the simulation process, and the solution completion condition includes: detecting the temperature convergence of the target monitoring point in the calculation domain, and the target monitoring point is located in the grid area where the bolt body or the welding nut is located.

[0013] In a second aspect, a vehicle simulation test device is provided, which includes: a three-dimensional modeling module, which is used to perform three-dimensional modeling of the grounding structure of the wiring harness terminal when a vehicle wiring harness and a wiring harness terminal of the vehicle wiring harness are selected, so as to obtain a three-dimensional simulation model of the grounding structure; a simulation parameter setting module, which is used to set the simulation parameters of the three-dimensional simulation model in simulation software; an operation module, which is used to run the simulation software according to the simulation parameters to obtain a simulation result of the three-dimensional simulation model; a determination module, which is used to determine the maximum allowable current of the current grounding structure at a preset maximum temperature according to the simulation result; a judgment module, which is used to judge whether the actual current carrying capacity of the grounding structure meets the power demand of electrical components according to the maximum allowable current; and an adjustment module, which is used to adjust the grounding structure if not, and perform simulation verification again based on the adjusted grounding structure until the actual current carrying capacity of the adjusted grounding structure meets the power demand.

[0014] In a third aspect, an electronic device is provided, comprising: a memory for storing executable program code; and a processor for calling and running the executable program code from the memory, so that the electronic device executes the method in the above-mentioned first aspect or any possible implementation of the first aspect.

[0015] In a fourth aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the method in the first aspect or any possible implementation of the first aspect.

[0016] In a fifth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the method in the above-mentioned first aspect or any possible implementation manner of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a current path of a grounding structure provided in an embodiment of the present application;

[0018] Figure 2 is a schematic flow chart of a vehicle simulation test method provided in an embodiment of the present application;

[0019] Figure 3 It is a schematic diagram of a curve corresponding to a curve equation of a φ8 four-legged welding nut provided in an embodiment of the present application;

[0020] Figure 4 It is a schematic diagram of a curve corresponding to a curve equation of a φ8 round fully welded nut provided in an embodiment of the present application;

[0021] Figure 5 It is a structural schematic diagram of a vehicle simulation test device provided in an embodiment of the present application;

[0022] Figure 6 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0024] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0025] Single-wire design is often used in automotive electrical circuit design. This single-wire design can be understood as: the vehicle's electrical components only have a positive circuit, and the negative circuit returns power to the negative electrode of the battery by grounding the vehicle body. In the selection of vehicle wiring harnesses, the corresponding specifications of wiring harnesses are selected according to the different powers of electrical components to ensure that the selected wiring harnesses will not be burned at high temperatures under the maximum power of the electrical components.

[0026] At present, the vehicle wiring harness design process mainly includes two steps: wiring harness selection and wiring harness terminal selection:

[0027] Wire harness selection means: according to the maximum continuous current in the circuit, select the wire harness model that meets the current requirements, including the wire harness material and wire diameter.

[0028] The selection of wiring harness terminals refers to the following: Appendix A of the national standard QC / T 1067.1-2017 "Connectors for automotive wiring harnesses and electrical equipment Part 1: Definitions, test methods and general performance requirements" stipulates that the temperature rise of the contact surface of the wiring harness terminal should not exceed 55°C under the maximum continuous current, so as to avoid the risk of high-temperature ablation caused by insufficient current carrying capacity of the wire terminal.

[0029] Through research, the embodiments of the present application have found that in the current automotive industry, the grounding nuts involved in the grounding structure mostly use four-corner spot-welded nuts, the contact area of ​​the welds is small, and there is a risk of insufficient current carrying capacity, which in turn leads to high-temperature ablation. However, due to the lack of analytical capabilities for the electrical-thermal conversion of the grounding structure in the current vehicle wiring harness design process, the risk of high-temperature fires caused by insufficient current carrying capacity of the grounding structure cannot be effectively identified. Therefore, how to avoid the risk of high-temperature fires caused by insufficient current carrying capacity of the grounding structure has become a technical problem that needs to be solved urgently.

[0030] See also Figure 1 , Figure 1 It is a schematic diagram of a current path of a grounding loop provided in an embodiment of the present application.

[0031] For example, Figure 1 As shown, the current path of the grounding loop includes: vehicle wiring harness 101, wiring harness terminal 102, welding nut 103, bolt body 104, and vehicle body sheet metal 105. The vehicle wiring harness 101 can also be called a wire, and correspondingly, the wiring harness terminal 102 can also be called a wire terminal.

[0032] In the embodiment of the present application, the grounding circuit refers to the entire circuit through which the current flows from the positive electrode to the negative electrode, including the battery, electrical components, the grounding structure and the connected wires. The grounding structure is a part of the grounding circuit, and the grounding structure is equivalent to the negative electrode of the entire grounding circuit. Grounding can be understood as: fastening the wire to the body sheet metal 105 with the bolt body 104. It should be noted that Figure 1 Some components on the current path of the grounding loop are shown in the figure, but not all components on the grounding loop are represented. Figure 1 The components shown in the figure can be understood as the grounding components in the grounding structure.

[0033] Specifically, the loop current flows in along the vehicle wiring harness 101, and is mainly transmitted to the body sheet metal 105 in the form of a grounding bolt through the wiring harness terminal 102. Specifically, the current is transmitted to the bolt body 104 through the wiring harness terminal 102, and then transmitted to the welding nut 103 through the bolt body 104, and then transmitted to the body sheet metal 105 through the nut welding point of the welding nut 103.

[0034] For example, Figure 1 As shown, the current path of the grounding loop also includes: a flat washer 106 and a spring washer 107. Figure 1 As shown, the process of current being transferred to the bolt body 104 through the harness terminal 102 is specifically as follows: the current passes through the harness terminal 102 , sequentially passes through the flat washer 106 and the spring washer 107 , and reaches the bolt body 104 .

[0035] When the current is transmitted in the above-mentioned grounding structure, the temperature rise will be generated according to the difference in the resistance value of each grounding component. If the grounding components selected in the grounding structure are not reasonable, such as insufficient current carrying capacity of the grounding components, it will cause local high temperature of the grounding components, and then ablation will occur, which may cause a fire in the whole vehicle.

[0036] Based on this, in order to at least avoid the risk of high-temperature fires caused by insufficient current-carrying capacity of the grounding structure, an embodiment of the present application provides a vehicle simulation test method, which is applied to electronic equipment, and the electronic equipment can be a computer device, and the computer device can be installed with simulation software. In the process of vehicle wiring harness design, the embodiment of the present application adds a simulation step of the grounding structure, which is conducive to effectively identifying the risk of high-temperature fires caused by insufficient current-carrying capacity of the grounding structure during the simulation stage, and by adjusting the grounding structure, avoiding the risk of high-temperature fires caused by insufficient current-carrying capacity of the grounding structure during the use of the actual vehicle.

[0037] Figure 2 It is a schematic flow chart of a vehicle simulation test method provided in an embodiment of the present application.

[0038] For example, Figure 2 As shown, the simulation test method of the vehicle includes:

[0039] Step 201: When a vehicle wiring harness and a wiring harness terminal of the vehicle wiring harness are selected, a grounding structure of the wiring harness terminal is three-dimensionally modeled to obtain a three-dimensional simulation model of the grounding structure.

[0040] Step 202: Setting simulation parameters of the three-dimensional simulation model in the simulation software.

[0041] Step 203: Run the simulation software according to the above simulation parameters to obtain the simulation results of the three-dimensional simulation model.

[0042] Step 204: According to the above simulation results, the maximum allowable current of the current grounding structure at a preset maximum temperature is determined.

[0043] Step 205: According to the maximum allowable current, determine whether the actual current carrying capacity of the ground structure meets the power demand of the power-consuming components. If yes, the process ends, otherwise, execute step 206.

[0044] Step 206: Adjust the grounding structure, and perform simulation verification again based on the adjusted grounding structure until the actual current carrying capacity of the adjusted grounding structure meets the above power demand.

[0045] exist Figure 2In the illustrated embodiment, after the vehicle wiring harness and wiring harness terminal are selected, the simulation of the grounding structure is further added. Through the simulation of the grounding structure, the electrical-thermal conversion of the grounding structure is also taken into account in the vehicle wiring harness design process. Thus, the risk of high-temperature fire caused by insufficient current-carrying capacity of the grounding structure can be effectively identified through simulation analysis in the simulation stage. In the case where the actual current-carrying capacity of the grounding structure does not meet the power demand of the electrical components, it means that the actual current-carrying capacity of the grounding structure is insufficient. By further adjusting the grounding structure and simulating and verifying the adjusted grounding structure again until the actual current-carrying capacity of the adjusted grounding structure meets the above-mentioned power demand, the risk of high-temperature fire caused by insufficient current-carrying capacity of the grounding structure can be effectively avoided during the subsequent actual use of the vehicle. By adding the simulation analysis of the grounding structure, the safety and reliability of the grounding structure can be ensured when the vehicle wiring harness and wiring harness terminal are selected, the overall performance of the vehicle wiring harness can be improved, and the risk of fire in the vehicle can be reduced.

[0046] Below Figure 2 The specific implementation method of each step in the embodiment shown is described as follows:

[0047] In step 201, the maximum power of the electrical components can be determined first, and the maximum continuous current that the vehicle wiring harness needs to carry can be determined based on the maximum power. According to the maximum continuous current, the wiring harness selection table is searched, and the appropriate wiring harness material and wire diameter are selected to ensure that the current carrying capacity of the wiring harness can meet the maximum continuous current requirements.

[0048] When selecting the wiring harness terminal, select the appropriate wiring harness terminal material and cross-sectional area according to the above maximum continuous current to ensure that the surface temperature rise of the wiring harness terminal does not exceed 55°C under the maximum continuous current. In this way, the risk of high-temperature ablation caused by insufficient current carrying capacity of the wiring harness terminal can be avoided.

[0049] That is to say, in the process of vehicle wiring harness design, the maximum power of the electrical components must be calculated first, and then the selection of wiring harness and terminals must be determined based on the maximum power. Maximum power is a key input parameter for designing wiring harness and terminals, ensuring that the wiring harness and wiring harness terminals can operate safely and reliably at maximum power. Through reasonable design and selection, the risk of high temperature ablation caused by insufficient current carrying capacity of the wiring harness or wiring harness terminals can be effectively avoided.

[0050] When the vehicle wiring harness and the wiring harness terminal of the vehicle wiring harness are selected, in an embodiment of the present application, the grounding structure of the wiring harness terminal will be three-dimensionally modeled to obtain a three-dimensional simulation model of the grounding structure. Since the grounding structure is equivalent to the negative pole of the entire grounding loop, the three-dimensional modeling of the grounding structure of the wiring harness terminal can mainly refer to the three-dimensional modeling of the negative pole part of the grounding loop. The three-dimensional simulation model mainly includes: various grounding components involved in the grounding structure. These grounding components may include: loop wires, bolt bodies, flat washers, spring washers, welding nuts, body sheet metal, etc. Grounding components can be understood as components located at the grounding position, and can also be understood as components in the grounding structure.

[0051] For example, three-dimensional modeling software can be used to Figure 1 The three-dimensional modeling of the shown grounding structure is performed to obtain a three-dimensional simulation model of the grounding structure. The three-dimensional modeling software can be: CATIA (Computer Aided Three Dimensional Interactive Application), UG (Unigraphics Solutions, unified graphics solutions) and the like.

[0052] In a possible implementation method, the grounding structure of the wiring harness terminal is three-dimensionally modeled to obtain a three-dimensional simulation model of the grounding structure, including: taking the center position of the through hole of the body sheet metal welded by the welding nut as the coordinate origin, taking the first direction as the x-axis direction, the second direction as the y-axis direction, and the third direction as the z-axis direction to establish a three-dimensional coordinate system; based on the three-dimensional coordinate system, importing each grounding component in the grounding structure to obtain a three-dimensional simulation model of the grounding structure.

[0053] For easier understanding, see Figure 1 The center position of the through hole of the body sheet metal 105 welded by the welding nut 103 is Figure 1 Point O in the diagram. The first direction, the second direction and the third direction can all be preset. For example, the first direction is set to the direction of the front of the vehicle, the second direction is set to the horizontal left-right direction perpendicular to the direction of the front of the vehicle, and the third direction is set to the vertical upward direction. Based on this, a three-dimensional coordinate system is established with the center position of the through hole of the body sheet metal 105 welded by the welding nut 103 as the coordinate origin, the direction of the front of the vehicle is set as the x-axis direction, the vertical upward direction is the z-axis direction, and the horizontal left-right direction is the y-axis direction. Then, based on the three-dimensional coordinate system, the various grounding components in the grounding structure are imported to obtain a three-dimensional simulation model of the grounding structure. The various grounding components in the grounding structure include but are not limited to: loop wires, i.e., the selected vehicle wiring harness, bolt body, flat washers, spring washers, welding nuts, body sheet metal, etc.

[0054] Exemplarily, the center position of the through hole of the above-mentioned body sheet metal can be: the center point of the circular hole on the crossbeam of the body sheet metal for welding the welding nut, or it can be: the center point of the circular hole on the longitudinal beam of the body sheet metal for welding the welding nut.

[0055] Taking into account that the conventional three-dimensional model of the whole vehicle usually also takes the direction of the vehicle's front as the x-axis direction, the vertical upward direction as the z-axis direction, and the horizontal left and right direction as the y-axis direction, therefore, when establishing the three-dimensional simulation model of the grounding structure, the embodiment of the present application adopts the same coordinate system establishment rules as the conventional three-dimensional model of the whole vehicle, which is conducive to maintaining the coordinate system consistency between the three-dimensional model of the whole vehicle and the three-dimensional simulation model of the grounding structure. The consistent coordinate system facilitates communication and collaboration between team members, can reduce errors introduced by coordinate system conversion, can more conveniently integrate data from different sources, facilitates integration and data exchange between different three-dimensional models, promotes the accuracy and reliability of simulation analysis, and improves the efficiency of the entire development process.

[0056] In step 202, the three-dimensional simulation model obtained by three-dimensional modeling can be imported into the simulation software to set the simulation parameters of the three-dimensional simulation model in the simulation software. The simulation parameters are used to ensure the accuracy and effectiveness of the simulation analysis, and these simulation parameters vary according to the specific simulation type and analysis purpose. For example, the simulation parameters may include material properties, boundary conditions, initial conditions, time steps and iteration times, grid settings, solver settings, etc.

[0057] The simulation software may be a commonly used simulation software in the automotive field, such as CAE (Computer-Aided Engineering) simulation software, MBD (Automated Dynamic Analysis and Design) simulation software, etc. In the embodiment of the present application, CAE simulation software may be used. CAE simulation software is mainly used to predict and optimize the performance of engineering products in real environments by establishing mathematical models and computer simulations, including structural analysis, fluid dynamics analysis, heat conduction analysis, and other aspects.

[0058] Exemplarily, the simulation parameters of the three-dimensional simulation model are set in the simulation software as described in the embodiment of the present application, including: setting the first type of simulation parameters and the second type of simulation parameters of the three-dimensional simulation model in the simulation software; wherein the first type of simulation parameters include: general simulation parameters preliminarily set for the three-dimensional simulation model; the second type of simulation parameters include: target attribute parameters set for each grounding component in the three-dimensional simulation model, the target attribute parameters include attribute parameters related to heat generation and attribute parameters related to heat dissipation.

[0059] In some embodiments, the first type of simulation parameters can be understood as simulation parameters that can be used universally for each grounding component in the three-dimensional simulation model, or can be understood as conventional setting parameters of the three-dimensional simulation model. The second type of simulation parameters can be understood as simulation parameters that are refined for each grounding component in the three-dimensional simulation model. The simulation software has a first type of window and a second type of window, so that the first type of simulation parameters can be set in the first type of window, and the second type of simulation parameters can be set in the second type of window.

[0060] Exemplarily, the first type of simulation parameters may include analysis type, fluid selection, solid selection, wall conditions, initial conditions and environment settings, etc. These simulation parameters are described below:

[0061] The analysis type refers to the simulation method selected according to the specific problem and goal. Selecting the appropriate analysis type is crucial to obtaining accurate simulation results. In the embodiment of the present application, the analysis type set for the three-dimensional simulation model of the grounding structure is: external flow analysis model.

[0062] The external flow analysis model is an analysis method specifically used to simulate the flow characteristics of fluids around objects. It usually focuses on the flow characteristics of fluids near the surface of objects, and can simplify calculations by setting reasonable boundary conditions. The external flow analysis model does not use the external solid surface as the analysis boundary, but only uses the set calculation domain boundary as the analysis boundary. If there is a closed cavity, the closed cavity can be considered, so that the flow analysis excludes the uninvolved internal space to reduce the computational resource requirements of complex models. Among the physical characteristics considered in the flow analysis, the heat conduction function in the solid is selected. The radiation model selects Monte Carlo, and the ambient temperature is set according to the actual air temperature of the environment to be simulated. The spectral characteristic definition standard selects discrete frequency bands, and the number of bands can be selected as 10. The direction of gravity is determined according to the modeling, and the embodiment of the present application is set to -9.81m / s according to the Z-direction component. 2 .

[0063] Fluid selection refers to the selection of a suitable fluid type according to the simulation requirements. The optional fluid types may include air, water, oil, etc. Different types of fluids have different physical properties. In the embodiment of the present application, the selected fluid type may be air. If other fluid types are involved, the fluid selection may be performed in the fluid subdomain.

[0064] Solid selection refers to the selection of the default solid material. Usually, the most commonly used solid material for each grounding component in the 3D simulation model can be selected as the default solid material. In this way, in the subsequent solid material setting for each grounding component, the number of components that need to set solid materials separately can be reduced.

[0065] Wall condition is an important parameter when simulating heat transfer and fluid dynamics problems, which mainly characterizes the heat transfer properties between various grounding components. In the embodiment of the present application, the wall condition selects a conventional heat conduction wall, and the radiation wall selects a blackbody radiation wall. Conventional heat conduction wall refers to the existence of heat conduction phenomenon on the wall, that is, heat can be transferred between the wall and the fluid. This wall condition is suitable for simulating heat exchange, heat transfer and other problems. Blackbody radiation wall means that the wall, as an ideal black body, can completely absorb all incident radiation energy and emit radiation energy with the same efficiency. The blackbody radiation wall proves that there is not only heat conduction between the wall and the fluid, but also radiation heat transfer, that is, the wall can act as a radiation source or receive radiation energy.

[0066] Initial conditions refer to the state of the system at the beginning of the simulation, including the initial distribution of parameters such as temperature, velocity, pressure, concentration, etc. These conditions are particularly important for simulating transient processes, as they determine the state of the system at the beginning of the simulation.

[0067] Environmental settings refer to the environment in which the system is located during the simulation process, including parameters such as temperature, pressure, speed, and boundary conditions related to the external environment. These conditions are crucial to the response of the simulation system, and they define the external environment in which the system is located. The boundary refers to the computational domain boundary, which refers to the edge of the simulation space, that is, the boundary of the simulated physical area.

[0068] In CAE simulation, although initial conditions and environmental settings may involve similar parameters, such as thermodynamic parameters, velocity parameters, turbulence parameters, solid parameters, and concentration parameters, they represent different concepts and uses. Initial conditions define the state of the system at the beginning of the simulation, while environmental settings define the external environmental conditions of the system. By setting these parameters reasonably, the accuracy and reliability of the simulation results can be ensured. The following is an explanation of the parameters involved in initial conditions and environmental settings:

[0069] The thermodynamic parameters in the initial conditions include: the temperature distribution of the system at the initial moment, the heat flux distribution on the surface of the system at the initial moment, and the heat source distribution inside the system at the initial moment. The thermodynamic parameters in the environment settings include: the temperature of the external environment during the simulation, the heat flux conditions on the boundary, the heat source conditions on the boundary, etc.

[0070] The velocity parameter in the initial condition refers to the velocity distribution of the system at the initial moment. The velocity parameter in the environment setting refers to the velocity condition on the boundary.

[0071] The turbulence parameters in the initial conditions include: the turbulence intensity distribution of the system at the initial moment, the turbulence kinetic energy distribution of the system at the initial moment, and the turbulence dissipation rate distribution of the system at the initial moment. The turbulence parameters in the environmental settings include: the turbulence intensity conditions on the boundaries, the turbulence kinetic energy conditions on the boundaries, and the turbulence dissipation rate conditions on the boundaries.

[0072] The concentration parameter in the initial condition refers to the concentration distribution in the system at the initial moment. The concentration parameter in the environmental setting refers to the concentration condition on the boundary.

[0073] Solid parameters are usually set as initial conditions to reflect the displacement state of the system at the beginning, including: the initial displacement distribution of the solid, the initial stress distribution of the solid, and the initial strain distribution of the solid.

[0074] Exemplarily, the second type of simulation parameters includes: target attribute parameters set for each grounding component in the three-dimensional simulation model, the target attribute parameters including attribute parameters related to heat generation and attribute parameters related to heat dissipation.

[0075] Considering that the heat generation process is due to the resistivity of the conductor itself, the current flows through the process to generate heat. Therefore, the core of simulating the heat generation process is to set the resistivity of each grounding component and the property of resistivity changing with temperature. Therefore, the property parameters related to heat generation include: the resistivity of each grounding component and the property of resistivity changing with temperature.

[0076] The heat dissipation part mainly considers the performance of heat conduction, heat radiation, and heat convection. Therefore, the attribute parameters related to heat dissipation include: specific heat, thermal conductivity, radiation emissivity, reflection type, surrounding convection coefficient, etc. of each grounding component.

[0077] In some embodiments, setting the second type of simulation parameters can be understood as: setting the property parameters related to heat generation and heat dissipation such as resistivity, thermal conductivity, and emissivity of the simulation object. The simulation object can include all the grounding components involved in the simulation, such as Figure 1 The various grounding components in the grounding structure shown.

[0078] In step 203, a run button is provided in the simulation software. By clicking the run button, the simulation software can be run according to the simulation parameters set above, thereby obtaining the simulation results of the three-dimensional simulation model. During the simulation process, the temperature changes of each grounding component under different currents can be mainly monitored to simulate the maximum temperature of each grounding component under different currents. The simulation results may include the temperature simulation results of each grounding component in the grounding structure under different currents.

[0079] Exemplarily, the simulation result can reflect the electrical-thermal conversion capability of the grounding structure, and may include temperature distribution results, current distribution results, or heat flow distribution results in the grounding structure.

[0080] The temperature distribution results are used to describe the temperature values ​​of each point in the calculation domain set for the 3D simulation model, and are used to evaluate the thermal equilibrium state in the calculation domain and identify the hot spot locations.

[0081] The current distribution result refers to the distribution of current in each component in the three-dimensional simulation model. The current distribution result is usually presented in the form of a current cloud map, showing the current density or current value at different locations. The current distribution result can include: current value distribution result and current density distribution result. The current value distribution result shows the current value at different locations, which helps to evaluate whether the current distribution is uniform and whether there is a local overload phenomenon; the current density distribution result shows the current value per unit area, which helps to evaluate the risk of local overheating and whether the current density exceeds the rated value.

[0082] Heat flux distribution results refer to the direction and rate of heat transfer, usually displayed in the form of vector diagrams or contour lines, showing the direction and intensity of heat transfer. Heat flux can be expressed as heat flux density, which is the rate of heat flow per unit area. Heat flux distribution can help evaluate the effectiveness of heat transfer, identify areas of concentrated heat flux, and evaluate the location of thermal bridges or thermal resistance.

[0083] Temperature distribution, heat flux distribution, and current distribution are all important concepts in thermal analysis. They provide information about the thermal state of the system from the perspectives of temperature, heat transfer, and current. By analyzing temperature distribution, heat flux distribution, and current distribution, the thermal management performance of the grounding structure can be evaluated and the design of the grounding structure can be optimized based on this.

[0084] In a possible implementation, step 203 includes the following steps 2031 to 2035:

[0085] Step 2031: Determine the calculation domain of the three-dimensional simulation model.

[0086] Among them, the calculation domain defines the spatial scope of the simulation analysis. In the embodiment of the present application, the calculation domain includes the three-dimensional simulation model itself and the spatial area around the three-dimensional simulation model to ensure the correct application of boundary conditions so that the impact of boundary conditions on internal heat transfer is minimized.

[0087] In the specific implementation, according to actual needs, the size of the calculation domain can be adjusted by dragging the calculation boundary on the simulation interface of the simulation software to obtain a reasonable calculation domain. By setting a reasonable calculation domain, the analysis time of the fluid flow in the three-dimensional simulation model can be compressed.

[0088] Step 2032: Perform global grid division on the computational domain to obtain a globally gridded computational domain.

[0089] Specifically, you can first select a grid type, such as a structured grid or an unstructured grid. Structured grids are suitable for regular geometric shapes, and unstructured grids are suitable for complex geometric shapes. In the embodiment of the present application, you can select the structured grid as the grid type. Then, determine the grid size and select a reasonable grid size to balance the calculation accuracy and calculation efficiency. In the embodiment of the present application, the X / Y / Z grid size can be set to 0.02mm. It should be noted that the 0.02mm is only an exemplary description, and the grid size is not limited to this in the specific implementation. Then, in the simulation software, based on the selected grid type and grid size, the computational domain is globally meshed to obtain a globally meshed computational domain.

[0090] Step 2033: Perform local mesh refinement on the globally meshed computational domain to obtain a local mesh refined computational domain.

[0091] Specifically, first determine the area that needs local refinement, that is, the refinement area, according to the simulation requirements. The refinement area may include: key areas of fluid flow or heat transfer, such as near the wall, flow separation area, etc. In the embodiment of the present application, fluid areas, solid areas, and fluid / solid boundary areas can be selected as refinement areas. In other words, the local refined grid mainly refines the fluid grid level, refines the solid grid level, and refines the grid level at the fluid / solid boundary. Then the grid refinement parameters can be set, for example, to determine the grid size and density of the refinement area. Usually, the grid size of the refinement area is much smaller than the global grid to improve local accuracy. Then, in the selected refinement area, local grid refinement is performed based on the grid refinement parameters to obtain the calculation domain of the local grid refinement.

[0092] Step 2034: According to the calculation domain of the local mesh refinement, the simulation calculation target in the simulation process is set.

[0093] The simulation calculation target refers to the control parameters used to control the simulation process and results during the simulation process. These control parameters ensure that the simulation is technically feasible and physically reasonable, thereby obtaining reasonable simulation results. The simulation software has a window for setting the simulation calculation target, through which the simulation calculation target can be entered.

[0094] Exemplarily, the simulation calculation target includes: a simulation calculation completion target, which is used to describe the solution completion condition of the simulation process. The solution completion condition refers to the process of judging when to end the simulation by monitoring certain key indicators during the simulation process. These key indicators are usually related to specific problems and are intended to ensure that the physical meaning of the simulation is met. In the embodiment of the present application, the key indicator monitored is the temperature change of each grounding component, that is, the temperature change of each grid in the calculation domain of the local grid refinement. And based on the three-dimensional simulation model of the grounding structure, the maximum temperature of the bolt body and the welding nut can be monitored in detail. When the grid area where the highest temperature is located is stable, it can be defined as the solution is completed.

[0095] Exemplarily, the solution completion conditions include: detecting the temperature convergence of the target monitoring point in the calculation domain, and the target monitoring point is located in the grid area where the bolt body or the weld nut is located. In simulation software, temperature convergence means that when performing thermal simulation calculations, the system temperature no longer changes significantly and reaches a state of equilibrium. In the embodiment of the present application, the temperature convergence of the target monitoring point can be understood as: the temperature of the target monitoring point no longer changes significantly in multiple iterations.

[0096] Optionally, the target monitoring point may be a point on the outer surface of the bolt body, or a point on the outer surface of the welding nut. Selecting a point on the outer surface as the target monitoring point makes it easier to measure the temperature.

[0097] Considering that the bolt body and the welding nut are the key grounding components in the grounding structure, their thermal stability may directly affect the performance of the entire grounding structure. The bolt body and the welding nut are often the hot spots in the grounding structure, and these components usually bear a large current. In addition, the bolt body and the welding nut are one of the main conduction paths of the current. When the current passes through these components, the Joule heating effect will be generated, resulting in a temperature increase. Therefore, in the embodiment of the present application, the temperature change of the bolt body and / or the welding nut is monitored, and the target monitoring point is set in the grid area where the bolt body or the welding nut is located, which is conducive to accurately evaluating the thermal distribution of the entire grounding structure and quickly judging whether the thermal management performance of the entire system meets the requirements.

[0098] Exemplarily, the simulation calculation target also includes: a simulation calculation end target and a simulation data preservation target.

[0099] The simulation calculation end target refers to the built-in standard for measuring whether to stop the solution process during the simulation. This built-in standard is called a target. Generally, the target convergence is set as one of the conditions for completing the calculation, that is, one of the conditions for stopping the solution process. In other words, the target setting refers to the termination conditions defined before the simulation starts. These conditions are used to determine when to end the simulation. These targets usually include a series of convergence criteria to ensure that the simulation results reach the expected accuracy.

[0100] The simulation data preservation target refers to the data preservation strategy during the simulation process. The embodiment of the present application can choose to save the completion result every 100 steps based on the number of iterations. The number of iterations can be understood as the number of calculations of the scanning grid.

[0101] It is understandable that the above simulation calculation end goal focuses on the mathematical convergence standard to ensure that the simulation results reach the expected accuracy and avoid invalid calculations. The above simulation calculation completion goal focuses on physical stability to ensure that the simulation results are physically reasonable and solve specific problems to ensure that the simulation results meet actual needs.

[0102] Step 2035: Run the simulation software according to the simulation parameters, and in the process of running the simulation software, perform simulation calculations according to the simulation calculation targets to obtain simulation data of the three-dimensional simulation model.

[0103] Specifically, in the process of running the simulation software, a gradient current from low to high can also be set to monitor the temperature changes of each grounding component in the grounding structure under different currents through the simulation software, and perform simulation calculations according to the simulation calculation target to obtain the simulation temperature under different currents. The temperature under each current can be calculated through the above-mentioned simulation calculation target. For example, in the simulation process for each current, when the temperature convergence of the target monitoring point is detected, the highest temperature of the grounding component at this time is used as the highest temperature of the grounding component under the current. It can be understood that the simulation software can obtain the temperature of each grid area in the calculation domain, so the highest temperature of the grounding component can be determined based on the temperature of each grid area. Based on this, the simulation data of the obtained three-dimensional simulation model can include: the highest temperature of each grounding component in the grounding structure under different currents.

[0104] In step 204, the maximum allowable current of the current grounding structure at a preset maximum temperature is determined according to the simulation results.

[0105] The preset maximum temperature can be determined based on the required ambient temperature and the maximum value of the temperature rise (i.e., the temperature rise amount) allowed for the grounding structure. Optionally, the preset maximum temperature can be equal to the sum of the required ambient temperature and the maximum value of the temperature rise allowed for the grounding structure. For example, if the required ambient temperature is 25°C, and it is required to avoid the temperature rise of the grounding structure exceeding 55°C, that is, the maximum value of the temperature rise allowed for the grounding structure is 55°C, then the preset maximum temperature is 25°C+55°C=80°C.

[0106] The above maximum allowable current represents the actual maximum current carrying capacity of the grounding structure at the preset maximum temperature. Since the simulation results include the maximum temperature of the grounding components in the grounding structure at different currents, the maximum allowable current of the grounding structure at the preset maximum temperature can be determined based on the simulation results. For example, if the simulation results just include the current corresponding to the preset maximum temperature, the corresponding current can be used as the maximum allowable current.

[0107] In some embodiments, the simulation results include: the maximum temperature of the grounding components in the grounding structure under different currents. An implementation method for determining the maximum allowable current of the current grounding structure at a preset maximum temperature based on the simulation results may include: performing curve fitting according to the maximum temperature of the grounding components in the grounding structure under different currents to obtain a curve equation corresponding to the grounding component; wherein the curve equation characterizes the relationship between the maximum temperature and current of the grounding component; substituting the preset maximum temperature into the above curve equation to calculate the maximum allowable current of the current grounding structure at the preset maximum temperature.

[0108] Specifically, for each grounding component in the grounding structure, the highest temperature corresponding to each current can be used as the horizontal and vertical coordinate values ​​of a fitting point, the current as the horizontal coordinate value, and the highest temperature corresponding to the current as the vertical coordinate value. Based on this, multiple fitting points can be obtained, and then a linear regression analysis can be performed based on the multiple fitting points to fit the curve equation of the grounding component. Then, the preset maximum temperature can be brought into the curve equation to calculate the maximum allowable current corresponding to the preset maximum temperature.

[0109] For example, the key grounding components in the grounding structure can be selected for fitting the curve equation, such as fitting the curve equation for the bolt body and / or the welded nut. The following takes the φ8 four-legged welded nut and the φ8 round fully welded nut as examples to illustrate the fitting of the curve equation and the solution of the maximum allowable current:

[0110] In a possible implementation, the welding nut in the current grounding structure is a φ8 four-legged welding nut. The simulation results include the maximum temperature of the φ8 four-legged welding nut under different currents. For example, different currents include: 80A, 100A, 120A, 140A, 160A, 180A, 200A. The highest temperatures corresponding to different currents are: 38.9°C, 46.3°C, 57.6°C, 70.4°C, 86.7°C, 102.1°C, 122°C. Based on this, the multiple fitting points obtained include: (80A, 38.9°C), (100A, 46.3°C), (120A, 57.6°C), (140A, 70.4°C), (160A, 86.7°C), (180A, 102.1°C), (200A, 122°C). According to the above multiple fitting points, the following curve equation is obtained by linear regression:

[0111] Tmax1=25.57-0.05357I+0.002679I 2 (Equation 1)

[0112] Where I is the continuous current in the grounding circuit, and Tmax1 is the maximum temperature of the φ8 four-pin welded nut. The curve corresponding to the curve equation of the φ8 four-pin welded nut can be found in Figure 3 . Figure 3 In the figure, the horizontal axis is the current, and the vertical axis is the maximum temperature of the φ8 four-pin welding nut ( Figure 3 The schematic diagram is as follows: Temperature - Four-corner welding)

[0113] If it is required to avoid the temperature rise of the grounding structure exceeding 55°C, the preset maximum temperature is required to be 80°C when the ambient temperature is 25°C. Substituting 80°C as Tmax1 into the above equation 1, it can be calculated that I=152.89A. This 152.89A is essentially the maximum allowable current of the φ8 four-legged welded nut at 80°C. In the embodiment of the present application, considering that the φ8 four-legged welded nut can be used as a key grounding component in the grounding structure, the maximum allowable current of the φ8 four-legged welded nut at 80°C can be used as the maximum allowable current of the grounding structure at 80°C.

[0114] In a possible implementation, the welding nut in the current grounding structure is a φ8 round all-welded nut, and the simulation results include the highest temperature of the φ8 round all-welded nut at different currents. For example, different currents include: 80A, 100A, 120A, 140A, 160A, 180A, 200A, and the highest temperatures corresponding to different currents are: 35.21°C, 41.33°C, 48.50°C, 57.36°C, 68.23°C, 81.85°C, 97.29°C. Based on this, the multiple fitting points obtained include: (80A, 35.21°C), (100A, 41.33°C), (120A, 48.50°C), (140A, 57.36°C), (160A, 68.23°C), (180A, 81.85°C), (200A, 97.29°C). According to the above multiple fitting points, the following curve equation is obtained through linear regression:

[0115] Tmax2=38.09-0.2435I+0.002708I 2 (Equation 2)

[0116] Where I is the continuous current in the grounding circuit, and Tmax2 is the maximum temperature of the φ8 round fully welded nut. The schematic diagram of the curve corresponding to the curve equation of the φ8 round fully welded nut can be found in Figure 4 . Figure 3 In the figure, the horizontal axis is the current, and the vertical axis is the maximum temperature of the φ8 round fully welded nut ( Figure 4 The schematic diagram is shown as: temperature - full welding).

[0117] If it is required to avoid the temperature rise of the grounding structure exceeding 55°C, the preset maximum temperature is required to be 80°C when the ambient temperature is 25°C. Substituting 80°C as Tmax2 into the above equation 2, it can be calculated that I=177.52A. This 177.52A is essentially the maximum allowable current of the φ8 circular fully welded nut at 80°C. In the embodiment of the present application, considering that the φ8 circular fully welded nut can be used as a key grounding component in the grounding structure, the maximum allowable current of the φ8 circular fully welded nut at 80°C can be used as the maximum allowable current of the grounding structure at 80°C.

[0118] Exemplarily, in order to further ensure the accuracy of the maximum allowable current of the current grounding structure at the preset maximum temperature, the curve fitting can be performed according to the maximum temperature of each grounding component in the grounding structure under different currents to obtain the curve equation corresponding to each grounding component. Combined with the method of determining multiple fitting points for the φ8 round fully welded nut and the φ8 four-legged welded nut described above, multiple fitting points can be determined for each grounding component in the grounding structure, so that curve fitting can be performed according to the multiple fitting points of each grounding component to obtain the curve equation corresponding to each grounding component. Then, the preset maximum temperature is respectively substituted into the curve equation corresponding to each grounding component to obtain the maximum allowable current of each grounding component at the preset maximum temperature. According to the maximum allowable current of each grounding component at the preset maximum temperature, the maximum allowable current of the grounding structure at the preset maximum temperature is determined.

[0119] Exemplarily, the minimum value of the maximum allowable current of each grounding component at a preset maximum temperature can be determined as the maximum allowable current of the grounding structure at the preset maximum temperature. For example, the maximum allowable current of each grounding component at the preset maximum temperature includes: the maximum allowable current 1 of the welding nut at the preset maximum temperature, the maximum allowable current 2 of the bolt body at the preset maximum temperature, the maximum allowable current 3 of the flat washer at the preset maximum temperature, and the maximum allowable current 4 of the spring washer at the preset maximum temperature. If the maximum allowable current 1 is the minimum value of these four maximum allowable currents, the maximum allowable current 1 can be determined as the maximum allowable current of the grounding structure at the preset maximum temperature.

[0120] In the embodiment of the present application, the minimum value of the maximum allowable current of each grounding component in the grounding structure at the preset maximum temperature is taken as the maximum allowable current of the grounding structure, which can ensure the safety of the entire grounding structure. Even at the preset maximum temperature, the maximum allowable current of any grounding component will not be exceeded, ensuring that the grounding component with the weakest current carrying capacity in the grounding structure will not become a safety hazard, thereby avoiding electrical failures or fire risks caused by insufficient current carrying capacity.

[0121] In step 205, the electrical components are: electrical components involved in the grounding circuit, that is, electrical components connected to the negative electrode of the battery through the grounding structure. Since the maximum allowable current can represent the actual current carrying capacity of the grounding structure, it can be determined based on the maximum allowable current whether the actual current carrying capacity of the grounding structure meets the power demand of the electrical components.

[0122] Exemplarily, judging whether the actual current carrying capacity of the grounding structure meets the power demand of the power-consuming components based on the maximum allowable current includes: determining the actual current demand of the power-consuming components. If the actual current demand is less than or equal to the maximum allowable current, then it is judged that the actual current carrying capacity of the grounding structure meets the power demand of the power-consuming components. If the actual current demand is greater than the maximum allowable current, then it is judged that the actual current carrying capacity of the grounding structure does not meet the power demand of the power-consuming components.

[0123] The actual demand current of the power-consuming components can be understood as the demand current calculated based on the maximum power of the power-consuming components. Therefore, the actual demand current can also be understood as the maximum demand current of the power-consuming components. If the grounding circuit involves multiple power-consuming components, the actual demand current is calculated based on the sum of the maximum powers of the multiple power-consuming components.

[0124] If the maximum demand current is less than or equal to the maximum allowable current of the above-mentioned grounding structure, it means that the current grounding structure has the ability to carry the maximum demand current, so it can be determined that the actual current carrying capacity of the current grounding structure meets the power demand of the electrical components, and further indicates that the current grounding structure does not need further adjustment. If the grounding structure does not need further adjustment, it can be determined that the selection process of the vehicle wiring harness and wiring harness terminal is completed to ensure that the selected vehicle wiring harness and wiring harness terminal are used in the actual vehicle application process, and there will be no risk of high temperature fire due to insufficient current carrying capacity of the grounding structure.

[0125] If the maximum demand current is greater than the maximum allowable current of the above-mentioned grounding structure, it means that the current grounding structure does not have the ability to carry the maximum demand current, and there is a risk of high-temperature ablation caused by insufficient current-carrying capacity of the grounding structure. Therefore, it is determined that the actual current-carrying capacity of the current grounding structure does not meet the power demand of electrical components, and further indicates that the current grounding structure needs to be further adjusted to further enhance the actual current-carrying capacity of the grounding structure.

[0126] In step 206, the actual current-carrying capacity of the enhanced grounding structure can be used as an adjustment target of the grounding structure to adjust the components in the grounding structure, for example, by increasing the conductive area of ​​the components, or changing the material of the components to a material with higher conductivity, etc., to adjust the components in the grounding structure. Then, simulation verification is performed again based on the adjusted grounding structure until the actual current-carrying capacity of the adjusted grounding structure meets the above-mentioned power demand. Performing simulation verification again can be understood as: using the adjusted grounding structure as the grounding structure in step 201, and re-executing steps 201 to 206. When the actual current-carrying capacity of the grounding structure after the final adjustment meets the above-mentioned power demand, it is determined that the selection process of the vehicle wiring harness and wiring harness terminal is completed to ensure that in the actual vehicle application process, the selected vehicle wiring harness and wiring harness terminal are used, and there is no risk of high-temperature fire due to insufficient current-carrying capacity of the grounding structure.

[0127] It is understandable that the heat generated by the grounding structure will directly affect the actual current carrying capacity of the grounding structure. By reducing the heat generation of the grounding structure, the current carrying capacity of the grounding structure can be significantly improved. According to the heat calculation formula Q=I*I*R, it can be seen that the heat Q is related to the current I and the resistance R. If you want to reduce the heat Q, you can do it by reducing the current I or the resistance R, but the current I is determined by the demand of the electrical components and cannot be reduced. Therefore, the heat reduction of the grounding structure can be achieved by reducing the resistance R. According to the calculation formula of the resistance R R=L*ρ / S, it can be seen that the resistance R is related to the resistivity ρ of the conductor, the conductive area S and the wire length L. Therefore, in order to reduce the resistance R, it can be achieved by increasing the conductive area S or reducing the resistivity ρ. Based on this, the implementation method of adjusting the grounding structure described in the embodiment of the present application may include: determining the target grounding component to be adjusted in the grounding structure; replacing the material of the target grounding component to reduce the resistivity ρ of the target grounding component; and / or, increasing the conductive area S of the target grounding component.

[0128] Among them, the target grounding component may be any grounding component in the grounding structure. For example, if the target grounding component is a welding nut or a bolt body, a welding nut or a bolt body with a larger conductive area can be reselected to replace the original welding nut or bolt body in the grounding structure, or a welding nut or a bolt body with a smaller resistivity can be reselected to replace the original welding nut or bolt body in the grounding structure.

[0129] In some embodiments, in order to more effectively select the target grounding component, the current density simulation results in the simulation results can be combined for selection. For example, according to the current density simulation results, the target area with the highest current density is determined in the calculation domain, and the grounding component that affects the current density of the target area is determined as the target grounding component, so that the current density of the target area can be reduced by increasing the conductive area of ​​the target grounding component. It is understandable that excessive current density may cause serious heating of the conductor, causing material performance degradation, insulation damage and even safety accidents. Therefore, by reducing the current density of the target area, it is beneficial to reduce the heat of the target area, so as to improve the actual current carrying capacity of the grounding structure to a certain extent.

[0130] In some embodiments, if the heat generation of the grounding structure is reduced by replacing the material of the target grounding component to reduce the resistivity ρ of the target grounding component, the cost of the material and the hardness of the material can be further combined. For example, for the resistivity of the material: the resistivity of iron> the resistivity of aluminum> the resistivity of copper, for the cost of the material: the cost of copper> the cost of aluminum> the cost of iron, and for the hardness of the material, the hardness of iron> the hardness of aluminum> the hardness of copper. Based on this, when replacing the material of the target grounding component, the cost and hardness of the material can also be combined to reduce the resistivity of the target grounding component while controlling the cost increase not to be too large and the hardness not to be reduced too much.

[0131] In summary, considering that electrical fires account for as much as 38% of the current causes of automobile fires. However, due to the lack of design standards, it is often difficult to identify the risk of ablation due to the loosening of the bolt body in the grounding structure of the vehicle wiring harness, which leads to a fire with a virtual connection. In the embodiment of the present application, by establishing a three-dimensional simulation model of the grounding structure and performing simulation, a method for quickly and accurately identifying the high-temperature fire risk of the grounding structure during the product data design stage is provided. Through the simulation software, the maximum temperature of each grounding component is simulated at the maximum design current of the grounding circuit, thereby avoiding the risk of high-temperature loosening of the bolt body or the grounding nut in the grounding structure, virtual connection of the wiring harness terminal, and then causing a vehicle fire.

[0132] Figure 5 It is a structural schematic diagram of a vehicle simulation test device provided in an embodiment of the present application.

[0133] For example, Figure 5 As shown, the vehicle simulation test device 500 includes:

[0134] A three-dimensional modeling module 501 is used to perform three-dimensional modeling of the grounding structure of the wiring harness terminal after selecting a vehicle wiring harness and a wiring harness terminal of the vehicle wiring harness, so as to obtain a three-dimensional simulation model of the grounding structure; a simulation parameter setting module 502 is used to set the simulation parameters of the three-dimensional simulation model in the simulation software; an operation module 503 is used to run the simulation software according to the simulation parameters to obtain the simulation results of the three-dimensional simulation model; a determination module 504 is used to determine the maximum allowable current of the current grounding structure at a preset maximum temperature according to the simulation results; a judgment module 505 is used to judge whether the actual current carrying capacity of the grounding structure meets the power demand of electrical components according to the maximum allowable current; an adjustment module 506 is used to adjust the grounding structure if not, and perform simulation verification again based on the adjusted grounding structure until the actual current carrying capacity of the adjusted grounding structure meets the power demand.

[0135] In one possible implementation, the simulation results include: the maximum temperature of the grounding components in the grounding structure under different currents; the determination module 504 is specifically used to: perform curve fitting according to the maximum temperature of the grounding components in the grounding structure under different currents to obtain a curve equation corresponding to the grounding components; wherein the curve equation characterizes the relationship between the maximum temperature of the grounding components and the current; the preset maximum temperature is substituted into the curve equation to calculate the maximum allowable current of the current grounding structure at the preset maximum temperature.

[0136] In one possible implementation, the judgment module 505 is specifically used to: determine the actual demand current of the electrical components; if the actual demand current is less than or equal to the maximum allowable current, determine that the actual current carrying capacity of the grounding structure meets the power demand of the electrical components; if the actual demand current is greater than the maximum allowable current, determine that the actual current carrying capacity of the grounding structure does not meet the power demand of the electrical components.

[0137] In one possible implementation, the adjustment module 506 is specifically used to: determine the target grounding component to be adjusted in the grounding structure; replace the material of the target grounding component to reduce the resistivity of the target grounding component; and / or increase the conductive area of ​​the target grounding component.

[0138] In one possible implementation, the grounding components in the grounding structure include: welding nuts and body sheet metal; the three-dimensional modeling module 501 is specifically used to: establish a three-dimensional coordinate system with the center position of the through hole of the body sheet metal welded by the welding nut as the coordinate origin, the first direction as the x-axis direction, the second direction as the y-axis direction, and the third direction as the z-axis direction; based on the three-dimensional coordinate system, import the grounding components in the grounding structure to obtain a three-dimensional simulation model of the grounding structure.

[0139] In one possible implementation, the simulation parameter setting module 502 is specifically used to: set the first type of simulation parameters and the second type of simulation parameters of the three-dimensional simulation model in the simulation software; wherein the first type of simulation parameters includes: general simulation parameters preliminarily set for the three-dimensional simulation model; the second type of simulation parameters includes: target attribute parameters set for each grounding component in the three-dimensional simulation model, and the target attribute parameters include attribute parameters related to heat generation and attribute parameters related to heat dissipation.

[0140] In a possible implementation, the running module 503 is specifically used to determine the computational domain of the three-dimensional simulation model; perform global grid division on the computational domain to obtain a globally gridded computational domain; perform local grid refinement on the globally gridded computational domain to obtain a locally grid refined computational domain; set a simulation calculation target in the simulation process according to the locally grid refined computational domain; run the simulation software according to the simulation parameters, and perform simulation calculations according to the simulation calculation targets during the running of the simulation software to obtain simulation data of the three-dimensional simulation model.

[0141] In one possible implementation, the grounding components in the three-dimensional simulation model include: a bolt body and a welding nut, and the simulation calculation target includes: a simulation calculation completion target; the simulation calculation completion target is used to describe the solution completion condition of the simulation process, and the solution completion condition includes: detecting the temperature convergence of the target monitoring point in the calculation domain, and the target monitoring point is located in the grid area where the bolt body or the welding nut is located.

[0142] Figure 6 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application.

[0143] For example, Figure 6 As shown, the electronic device 600 includes: a memory 601 and a processor 602, wherein the memory 601 stores an executable program code 6011, and the processor 602 is used to call and execute the executable program code 6011 to perform a vehicle simulation test method.

[0144] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform a vehicle simulation test method provided by an embodiment of the present application.

[0145] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0146] In the case of dividing each functional module according to each function, the device may also include a three-dimensional modeling module, a simulation parameter setting module, an operation module, a determination module, a judgment module, and an adjustment module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, and will not be repeated here.

[0147] It should be understood that the device provided in this embodiment is used to execute the above-mentioned vehicle simulation test method, and thus can achieve the same effect as the above-mentioned implementation method.

[0148] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to an electronic device, the processing module may be used to control and manage the actions of the electronic device. The storage module may be used to support the electronic device in executing related program codes, etc.

[0149] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in conjunction with the disclosure of the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0150] In addition, the device provided in the embodiments of the present application may specifically be a chip, component or module, and the chip may include a connected processor and memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a vehicle simulation test method provided in the above embodiment.

[0151] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is executed on a computer, the computer executes the above-mentioned related method steps to implement a vehicle simulation test method provided in the above embodiment.

[0152] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement a vehicle simulation test method provided in the above embodiment.

[0153] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0154] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0155] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0156] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A vehicle simulation test method, characterized in that: The method comprises: When a vehicle wiring harness and a wiring harness terminal of the vehicle wiring harness are selected, a grounding structure of the wiring harness terminal is three-dimensionally modeled to obtain a three-dimensional simulation model of the grounding structure; Setting simulation parameters of the three-dimensional simulation model in simulation software; According to the simulation parameters, the simulation software is run to obtain the simulation result of the three-dimensional simulation model; Determine the maximum allowable current of the current grounding structure at a preset maximum temperature according to the simulation result; According to the maximum allowable current, determining whether the actual current carrying capacity of the grounding structure meets the power demand of the power-consuming components; If not, the grounding structure is adjusted, and simulation verification is performed again based on the adjusted grounding structure until the actual current carrying capacity of the adjusted grounding structure meets the power demand.

2. The method according to claim 1, characterized in that: The simulation results include: the maximum temperature of the grounding components in the grounding structure under different currents; Determining the maximum allowable current of the current grounding structure at a preset maximum temperature according to the simulation result includes: According to the maximum temperature of the grounding component in the grounding structure under different currents, curve fitting is performed to obtain a curve equation corresponding to the grounding component; wherein the curve equation represents the relationship between the maximum temperature of the grounding component and the current; The preset maximum temperature is substituted into the curve equation to calculate the maximum allowable current of the current grounding structure at the preset maximum temperature.

3. The method according to claim 1, characterized in that The step of judging whether the actual current carrying capacity of the grounding structure meets the power demand of the power-consuming components according to the maximum allowable current includes: Determining the actual current demand of the power-consuming components; If the actual required current is less than or equal to the maximum allowable current, it is determined that the actual current carrying capacity of the grounding structure meets the power demand of the power-consuming component; If the actual required current is greater than the maximum allowable current, it is determined that the actual current carrying capacity of the grounding structure does not meet the power demand of the power-consuming component.

4. The method according to claim 3, characterized in that The step of adjusting the grounding structure comprises: Determining a target grounding component to be adjusted in the grounding structure; The material of the target grounding component is replaced to reduce the resistivity of the target grounding component; and / or the conductive area of ​​the target grounding component is increased.

5. The method according to claim 1, characterized in that The grounding components in the grounding structure include: welding nuts and body sheet metal; The three-dimensional modeling of the grounding structure of the wiring harness terminal to obtain a three-dimensional simulation model of the grounding structure includes: A three-dimensional coordinate system is established with the center position of the through hole of the body sheet metal welded by the welding nut as the coordinate origin, the first direction as the x-axis direction, the second direction as the y-axis direction, and the third direction as the z-axis direction; Based on the three-dimensional coordinate system, each grounding component in the grounding structure is imported to obtain a three-dimensional simulation model of the grounding structure.

6. The method according to claim 1, characterized in that Setting simulation parameters of the three-dimensional simulation model in the simulation software includes: Setting the first type of simulation parameters and the second type of simulation parameters of the three-dimensional simulation model in the simulation software; The first type of simulation parameters include: general simulation parameters preliminarily set for the three-dimensional simulation model; The second type of simulation parameters includes: target attribute parameters set for each grounding component in the three-dimensional simulation model, and the target attribute parameters include attribute parameters related to heat generation and attribute parameters related to heat dissipation.

7. The method according to claim 1, characterized in that The step of running the simulation software according to the simulation parameters to obtain simulation data of the three-dimensional simulation model includes: Determining a computational domain of the three-dimensional simulation model; Performing global grid division on the computational domain to obtain a globally gridded computational domain; Performing local mesh refinement on the global meshed computational domain to obtain a local mesh refined computational domain; According to the calculation domain of the local mesh refinement, a simulation calculation target is set in the simulation process; The simulation software is run according to the simulation parameters, and during the running of the simulation software, simulation calculation is performed according to the simulation calculation target to obtain simulation data of the three-dimensional simulation model.

8. The method according to claim 7, characterized in that The grounding parts in the three-dimensional simulation model include: a bolt body and a welding nut, and the simulation calculation target includes: a simulation calculation completion target; The simulation calculation completion target is used to describe the solution completion conditions of the simulation process, and the solution completion conditions include: detecting the temperature convergence of the target monitoring point in the calculation domain, and the target monitoring point is located in the grid area where the bolt body or the welding nut is located.

9. An electronic device, characterized in that: The electronic device comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory, so that the electronic device executes the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 8 is implemented.

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