A battery pack structure safety verification method and related device, and a storage medium

Abstract

The application discloses a battery pack structure safety verification method and related device and storage medium, and the method comprises the steps of: constructing a simulation model of a target battery pack; wherein the simulation model comprises a box main structure system model, a cell system model, an electrical system model and a thermal management system model of the target battery pack; simulating each target simulation item by using the simulation model of the target battery pack, to obtain the current simulation result corresponding to each target simulation item; wherein the target simulation item comprises modal simulation, random vibration simulation, bottom ball impact simulation, cell swelling cycle life simulation and bonding performance simulation; judging whether the current simulation result corresponding to each target simulation item is qualified; if the current simulation result corresponding to any target simulation item is unqualified, optimizing the simulation model of the target battery pack, and returning to re-simulate until the current simulation result corresponding to each target simulation item is qualified, and ending the simulation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power battery development, and in particular relates to a battery pack structure safety verification method and related device and storage medium. BACKGROUND

[0002] With the increasing proportion of new energy vehicles in the entire automobile market, the structural safety of vehicle-mounted power batteries has become the focus of attention. There are many factors affecting the safety of power batteries, such as impact, vibration, expansion, etc., so the structural safety of power batteries is very complex.

[0003] Currently, in order to ensure the structural safety of power batteries, the power batteries are mainly developed and designed based on previous experience. Then, the physical sample of the power battery pack is made according to the current design scheme, and the safety of the specified structure of the power battery is tested by using the physical sample of the power battery pack, and the parameters of the design are adjusted according to the test results until the power battery pack passes the safety test.

[0004] However, since the power battery is in the design and development stage, the design is not finalized, and the design scheme is not necessarily accurate, so the corresponding sample may not be made, and the test cannot be performed, and only the design scheme can be continuously adjusted. Moreover, the sample making is not only high in cost, but also complex, and it is difficult to ensure accuracy, and the current test is not comprehensive, so the current method not only makes the development efficiency of the power battery low, but also makes it difficult to ensure the safety of the structure of the power battery pack. SUMMARY

[0005] Based on the deficiencies of the prior art, the present application provides a battery pack structure safety verification method and related device and storage medium to solve the problems of low efficiency and inability to ensure structural safety of the prior art.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme:

[0007] The first aspect of the present application provides a battery pack structure safety verification method, comprising:

[0008] S101, modeling a target battery pack to obtain a simulation model of the target battery pack; wherein the simulation model of the target battery pack includes a box body structure system model, a cell system model, an electrical system model and a thermal management system model of the target battery pack;

[0009] S102, for each target simulation item, using the current simulation model of the target battery pack to simulate the target simulation item, and obtaining the current simulation result corresponding to the target simulation item; wherein, the target simulation item includes modal simulation, random vibration simulation, bottom ball impact simulation, cell swelling cycle life simulation, and bonding performance simulation; the modal simulation is performed with the simulation result of the target pre-stress as the initial physical field boundary condition of the modal simulation; the target pre-stress is the reaction compression force of the battery pack box frame structure after being pressed by the cell module swelling force; the random vibration simulation is performed with the structural damping and material damping as the modal damping of the battery pack; the bottom ball impact simulation includes simulation of ball impact on the bottom of the battery pack by using different energy extrusion heads of various shapes; the cell swelling cycle life simulation simulates the fatigue strength of a plurality of specified components in the battery pack when the swelling force cyclically changes during the battery charging and discharging process; and the bonding performance simulation simulates the bonding performance of each bonding interface in the battery pack under the swelling and mechanical impact of the battery pack.

[0010] S103, judging whether the current simulation results corresponding to each target simulation item are all qualified;

[0011] S104, if it is judged that the current simulation result corresponding to any one of the target simulation items is unqualified, optimizing the current simulation model of the target battery pack, and returning to execute the simulation of each target simulation item using the optimized simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item;

[0012] S105, if it is judged that the current simulation results corresponding to each target simulation item are all qualified, ending the simulation of the target battery pack.

[0013] Optionally, in the battery pack structure safety verification method described above, the modeling of the target battery pack to obtain the simulation model of the target battery pack comprises:

[0014] S201, removing the small chamfer on the box body structure of the target battery pack by geometric cleaning, extracting the middle surface of the sheet metal part, establishing a weld according to the welding position, and setting a regular circular hole grid in the locking area of the bolt, to obtain the box body structure system model of the target battery pack;

[0015] S202, establishing the model of each component of the cell of the target battery pack, and simulating the mechanical assembly connection relationship between each component, to obtain the cell system model of the target battery pack;

[0016] S203, solidifying digital-analog of each electrical component of the target battery pack, and then performing three-dimensional tetrahedral solid modeling to obtain a model of each electrical component, and extracting middle surfaces of various electrical connector components, and simulating mechanical assembly through motion coupling constraints to obtain an electrical system model of the target battery pack;

[0017] S204, extracting shells of the cold plate of the target battery pack, and planning feature lines of flow channels, non-flow channels, and brazing areas, and performing solid modeling on foam, structural adhesive, and thermal conductive adhesive of the thermal management system to obtain a thermal management system model of the target battery pack;

[0018] S205, simulating the connection relationship between the thermal management system of the target battery and the main body structure system of the box according to the installation process of the cold plate of the target battery.

[0019] Optionally, in the battery pack structure safety verification method described above, when the target simulation item is the modal simulation, the simulation of the target simulation item using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item comprises:

[0020] S301, performing simulation analysis of the target prestress on the assembly simulation working condition containing the target prestress;

[0021] S302, based on the physical field obtained by completing the simulation analysis of the target prestress, performing modal simulation analysis on the simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item.

[0022] Optionally, in the battery pack structure safety verification method described above, when the target simulation item is the random vibration simulation, the simulation of the target simulation item using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item comprises:

[0023] S401, setting the structural damping of the target battery pack and the material damping of the components as the modal damping of the target battery pack, and setting the vibration frequency spectrum loading curve of the target battery pack;

[0024] S402, performing random vibration simulation using the simulation model of the target battery pack according to the modal damping and the vibration frequency spectrum loading curve of the target battery pack to obtain the current simulation result corresponding to the random vibration simulation.

[0025] Optionally, in the battery pack structure safety verification method described above, when the target simulation item is the bottom ball impact simulation, the simulation of the target simulation item using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item comprises:

[0026] S501, for each ball strike combination, respectively, on the basis of the simulation model of the target battery pack, the simulation model corresponding to the ball strike combination is established, and the simulation initial boundary condition corresponding to the ball strike combination is set; wherein one ball strike combination includes an extrusion head with a certain shape and an extruded energy;

[0027] S502, according to the simulation initial boundary condition corresponding to each ball strike combination, the bottom ball strike simulation of the battery pack is carried out through the simulation model corresponding to each ball strike combination, and the current simulation result corresponding to the bottom ball strike simulation is obtained.

[0028] Optionally, in the battery pack structure safety verification method described above, when the target simulation item is the cell expansion cycle life simulation, the simulation of the target simulation item by using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item comprises:

[0029] S601, using the current simulation model of the target battery pack, the expansion force of the target components of the target battery pack in the charging and discharging process is simulated;

[0030] S602, according to the maximum expansion force and the minimum expansion force of each target component obtained by simulation, the stress amplitude of each target component is calculated;

[0031] S603, by comparing the stress amplitude of each target component with the fatigue strength of the material of each target component, the current simulation result corresponding to the cell expansion cycle life simulation is determined.

[0032] Optionally, in the battery pack structure safety verification method described above, when the target simulation item is the adhesion performance simulation, the simulation of the target simulation item by using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item comprises:

[0033] S701, setting the expansion coefficient and the initial temperature on the simulation model of the target battery pack;

[0034] S702, using the simulation model of the target battery pack to simulate the expansion force and the mechanical impact, and obtaining the stress of each adhesive interface of the target battery pack;

[0035] S703, respectively, the maximum stress in the stress of each adhesive interface is compared with the adhesive peel strength of the adhesive of each adhesive interface, and the current simulation result corresponding to each adhesive interface is determined;

[0036] S704, calculating stress averages of each of the adhesive interfaces, and determining adhesive failure degrees of each of the adhesive interfaces according to the stress averages of each of the adhesive interfaces.

[0037] The second aspect of the present application provides a battery pack structure safety verification device, comprising:

[0038] A modeling unit is configured to model a target battery pack by using a mechanical model to obtain a simulation model of the target battery pack; wherein the simulation model of the target battery pack comprises a box body structure system model, a cell system model, an electrical system model, and a thermal management system model of the target battery pack.

[0039] A simulation unit is configured to, for each target simulation item, simulate the target simulation item by using the current simulation model of the target battery pack to obtain a current simulation result corresponding to the target simulation item; wherein the target simulation item comprises modal simulation, random vibration simulation, bottom ball impact simulation, cell swelling cycle life simulation, and adhesive performance simulation; the modal simulation is performed by using a simulation result of a target pre-stress as an initial physical field boundary condition of the modal simulation; the target pre-stress is a counter-pressing force on a cell surface generated by a battery pack box frame structure after being pressed by a cell module swelling force; the random vibration simulation is performed by using structural damping and material damping as modal damping of the battery pack; the bottom ball impact simulation comprises simulating a ball impact on the bottom of the battery pack by using multiple extrusion heads with different energies and shapes; the cell swelling cycle life simulation simulates the fatigue strength of multiple specified components in the battery pack when the swelling force cyclically changes during the battery charging and discharging process; and the adhesive performance simulation simulates the adhesive performance of each adhesive interface in the battery pack under battery swelling and mechanical impact.

[0040] A judgment unit is configured to judge whether the current simulation results corresponding to each of the target simulation items are all qualified.

[0041] An optimization unit is configured to, when it is judged that the current simulation result corresponding to any one of the target simulation items is unqualified, optimize the current simulation model of the target battery pack, and return the simulation unit to perform the simulation of each target simulation item by using the optimized simulation model of the target battery pack to obtain the current simulation result corresponding to each target simulation item.

[0042] An ending unit is configured to, when it is judged that the current simulation results corresponding to each of the target simulation items are all qualified, end the simulation of the target battery pack.

[0043] The third aspect of the present application provides an electronic device, comprising:

[0044] The memory and the processor;

[0045] The memory is configured to store a program.

[0046] The processor is configured to execute the program, and the program, when executed, is specifically configured to implement the battery pack structure safety verification method according to any one of the preceding embodiments.

[0047] The fourth aspect of the present application provides a computer storage medium configured to store a computer program, and the computer program, when executed by a processor, is configured to implement the battery pack structure safety verification method according to any one of the preceding embodiments.

[0048] The application provides a battery pack structure safety verification method. A target battery pack is subjected to mechanical model modeling to obtain a simulation model of the target battery pack. The simulation model of the target battery pack includes a box main body structure system model, a cell system model, an electrical system model and a thermal management system model of the target battery pack, so that a complete battery pack model is constructed, and the conditions of each system in the verification process are determined subsequently. Then, for each target simulation item, the simulation of the target simulation item is performed by using the simulation model of the current target battery pack to obtain the current simulation result corresponding to the target simulation item. The target simulation item includes modal simulation, random vibration simulation, bottom ball impact simulation, cell swelling cycle life simulation and bonding performance simulation. The modal simulation is performed by taking the simulation result of the target prestress as the initial physical field boundary condition of the modal simulation. The target prestress is the counteracting compression force of the battery pack box frame structure to the cell surface after being compressed by the cell module swelling force. The random vibration simulation is performed by taking the structural damping and material damping as the modal damping of the battery pack. The bottom ball impact simulation includes the simulation of the bottom ball impact of the battery pack by using the extrusion heads with different energy and shapes. The cell swelling cycle life simulation simulates the fatigue strength of a plurality of specified components in the battery pack when the swelling force cyclically changes in the battery charging and discharging process. The bonding performance simulation simulates the bonding performance of each bonding interface in the battery pack under the swelling and mechanical impact of the battery pack, so that the comprehensive simulation verification of the target battery pack is realized. Then, it is judged whether the current simulation results corresponding to each target simulation item are all qualified. If it is judged that the current simulation result corresponding to any one target simulation item is unqualified, the simulation model of the current target battery pack is optimized, and the simulation of each target simulation item is performed by using the simulation model of the optimized target battery pack to obtain the current simulation result corresponding to the target simulation item, so that the battery design can be continuously optimized until it passes the safety verification. If it is judged that the current simulation results corresponding to each target simulation item are all qualified, the simulation of the target battery pack is ended, so that the modal simulation, random vibration simulation, bottom ball impact simulation, cell swelling cycle life simulation and bonding performance simulation of the battery are performed by using the constructed simulation model of the battery pack, the comprehensive verification of the safety of the structure of the battery pack can be realized without constructing the battery pack sample, the development efficiency of the battery is effectively improved, and the safety of the structure of the developed battery pack is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, brief descriptions will be given to the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0050] Figure 1 A flowchart of a battery pack structure safety verification method provided for an embodiment of the present application;

[0051] Figure 2 A flowchart of a method for establishing a simulation model of a target battery pack provided for an embodiment of the present application;

[0052] Figure 3 A flowchart of a method for modal simulation of a battery pack provided for an embodiment of the present application;

[0053] Figure 4 A flowchart of random vibration simulation of a battery pack provided for an embodiment of the present application;

[0054] Figure 5 A flowchart of bottom ball impact simulation of a battery pack provided for an embodiment of the present application;

[0055] Figure 6 A flowchart of a method for cell swelling cycle life simulation of a battery pack provided for an embodiment of the present application;

[0056] Figure 7 A flowchart of a method for bonding performance simulation of a battery pack provided for an embodiment of the present application;

[0057] Figure 8 An architectural schematic diagram of a battery pack structure safety verification device provided for an embodiment of the present application;

[0058] Figure 9 An architectural schematic diagram of an electronic device provided for an embodiment of the present application. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0060] In this application, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "including a" does not exclude the presence of additional same elements in the process, method, article or equipment including the element.

[0061] The embodiment of the present application provides a battery pack structure safety verification method, as shown in the figure, which comprises the following steps. Figure 1

[0062] S101, a mechanical model of a target battery pack is modeled to obtain a simulation model of the target battery pack.

[0063] The target battery pack can be any battery pack that needs to be simulated.

[0064] In order to establish an accurate mechanical model of the target battery and determine the conditions of each system of the target battery pack in the simulation process, the simulation model of the target battery pack includes a box body structure system model of the target battery pack, a cell system model, an electrical system model and a thermal management system model.

[0065] Specifically, the box body structure system model of the target battery pack, the cell system model, the electrical system model and the thermal management system model of the target battery pack can be respectively constructed according to the design parameters of each system of the target battery pack, and the connection relationship between each system is constructed, so that each system constitutes a whole target battery pack.

[0066] Optionally, in another embodiment of the present application, a specific implementation of step S101 comprises the following steps, as shown in the figure. Figure 2

[0067] S201, through geometric cleaning, remove the small chamfer on the box body structure of the target battery pack, extract the middle surface of the sheet metal part, establish the weld according to the welding position, and set a regular circular hole grid in the locking area of the bolt to obtain the box body structure system model of the target battery pack.

[0068] Specifically, the simulation modeling of the box body structure system mainly removes the small chamfer through geometric cleaning, extracts the middle surface of the sheet metal part, establishes the weld according to the actual welding position, and specially designs a regular circular hole grid in the locking area of the bolt of the battery pack.​​

[0069] S202, a model of each component of the target battery pack is established, and the mechanical assembly connection relationship between each component is simulated to obtain a battery cell system model of the target battery pack.

[0070] Specifically, the modeling of the simulation model of the battery cell system mainly establishes the models of the battery cell shell, the battery cell winding, the battery cell pole, the battery cell gasket, the silicon foam, the insulating PC, or the aerogel, the mica, and other components between the battery cells, and as much as possible to simulate the mechanical assembly connection relationship between each component. Among them, the two ends of the various fillers between the battery cells can be specifically treated as TIE contact connection.

[0071] S203, after the real block digital model of each electrical component of the target battery pack is obtained, a three-dimensional tetrahedral solid modeling is performed to obtain the model of each electrical component, and the middle surface of each type of electrical connector is extracted, and the mechanical assembly is simulated through motion coupling constraint to obtain an electrical system model of the target battery pack.

[0072] Specifically, the simulation modeling of the electrical system of the battery pack mainly performs 3D tetrahedral solid modeling on the electrical component real block digital model of various contactors, fuses, BMS, BDU, etc. After the injection molding shell is adjusted, the material density is the same as the actual weight. Then simulate the mechanical assembly through motion coupling constraint. Among them, the middle surface of the copper wire harness and the thin shell metal support used for binding and fixing is extracted, and the mechanical assembly is simulated through motion coupling constraint.

[0073] S204, the cold plate of the target battery pack is extracted, and the feature lines of the flow channel, the non-flow channel, and the brazing area are planned, and the foam, the structural adhesive, and the thermal conductive adhesive of the thermal management system are modeled to obtain a thermal management system model of the target battery pack.

[0074] Specifically, for the thermal management system of the battery pack, the cold plate is extracted, and the feature lines of the flow channel and the non-flow channel, and the brazing area are reserved, and the foam and the structural adhesive and the thermal conductive adhesive of the thermal management system are modeled.

[0075] S205, according to the installation process of the cold plate of the target battery pack, the connection relationship between the thermal management system of the target battery and the main structure system of the box body is simulated.

[0076] Among them, if it is friction stir welding, a common node solid weld is modeled, and if it is FDS process, screws of each FDS flow drill hole are established.

[0077] S102, for each target simulation item, the current simulation model of the target battery pack is used to simulate the target simulation item to obtain the current simulation result corresponding to the target simulation item.

[0078] Among them, the target simulation items include modal simulation, random vibration simulation, bottom ball impact simulation, cell expansion cycle life simulation, and bonding performance simulation, that is, in order to comprehensively test the structural safety of the target battery pack, the simulation models of the target battery pack are respectively used to perform the above-mentioned simulation.

[0079] It should be noted that the current battery pack modal simulation generally only considers the fixed constraint of the fixed point of the battery pack. The stiffness change of the entire cell module after the battery pack box structure is affected by the expansion pressure of the cell in the actual charge and discharge cycle is not considered, which causes a large difference between the simulation and the actual stress boundary, the simulation structure precision is slightly poor, and the state of the actual product cannot be accurately predicted, thereby causing the design failure of the product and the repeated test and verification of the sample. Therefore, in the embodiment of the present application, the target prestress is introduced. The target prestress is the counteracting compression force of the cell large face after the battery pack box frame structure is extruded by the expansion force of the cell module. Therefore, the modal simulation is performed with the simulation result of the target prestress as the initial physical field boundary condition.

[0080] The current simulation method lacks consideration of the large difference in vibration attenuation characteristics of different component materials, and only the same quantitative parameters are assigned, thereby causing low simulation progress. Therefore, in the embodiment of the present application, the structural damping and material damping are used as the modal damping of the battery pack in the random vibration simulation, which can more accurately predict the safety of the battery pack structure vibration and avoid the vibration structure failure problem of the designed battery pack in the subsequent vibration test and actual use condition.

[0081] For the bottom ball impact simulation, in order to consider various harsh publics of the bottom protection of the battery pack, the structural safety of the bottom protection is more applicable, so in the embodiment of the present application, the bottom ball impact simulation includes the simulation of the bottom of the battery pack by the extrusion head of different energy and various shapes.

[0082] The existing expansion force test only considers the structural strength at the peak value of the cell expansion force, and ignores the fact that the battery pack undergoes the expansion force cycle from the lowest SOC charge to the highest SOC, and then discharges from the highest SOC to the lowest SOC. That is, the cycle life of the cell expansion force is not considered and is not included in the check. Therefore, in the embodiment of the present application, the fatigue strength when the expansion force cycle changes is considered on the basis of the existing expansion force check. Therefore, the cell expansion cycle life simulation in the embodiment of the present application simulates the fatigue strength of multiple specified components in the battery pack when the expansion force cycle changes in the battery charge and discharge process.

[0083] With the increasing integration of power batteries, CTP technology uses a large amount of adhesion to improve the structural strength of the battery pack, so the adhesion of the battery pack is an important structural safety investigation item for the long-life service of the vehicle in various harsh working environments. At present, there is basically no simulation technology disclosed for this simulation condition. Therefore, in the embodiment of the present application, on the basis of the existing expansion force and mechanical impact simulation technology, a bonding performance simulation is proposed. The bonding performance simulation simulates the bonding performance of each bonding interface in the battery pack under the expansion and mechanical impact of the battery pack.

[0084] Optionally, in another embodiment of the present application, when the target simulation item is modal simulation, a specific implementation of step S102, i.e., a specific implementation of modal simulation of the battery pack, as shown in Figure 3

[0085] S301, target pre-stress simulation analysis is performed on the assembly simulation condition containing the target pre-stress.

[0086] S302, on the basis of the physical field obtained by completing the target pre-stress simulation analysis, modal simulation analysis is performed on the simulation model of the target battery pack, to obtain the current simulation result corresponding to the target simulation item.

[0087] Specifically, in the embodiment of the present application, the assembly simulation condition of the target pre-stress is introduced, and after completing this pre-stress analysis, modal simulation analysis is performed on the basis of the physical field result, so that the simulation result of the target pre-stress is taken as the initial physical field boundary condition of the modal simulation, which is equivalent to completing the mechanical environment simulation of the battery pack in the real installation and tooling environment. Through this simulation method, the simulation accuracy and the consistency with the actual product test results are improved.

[0088] For example, as shown in Table 1 below, the modal analysis result of the pre-stress loading is compared with the modal result without pre-stress loading and the test data, and it can be seen that the pre-stress loading model analysis method has higher accuracy.

[0089] Table 1

[0090]

[0091] Optionally, in another embodiment of the present application, when the target simulation item is random vibration simulation, a specific implementation of step S102, i.e., a specific implementation of random vibration simulation of the battery pack, as shown in Figure 4

[0092] S401, the structural damping of the target battery pack and the material damping of the components are set as the modal damping of the target battery pack, and the vibration frequency spectrum loading curve of the target battery pack is set.

[0093] ​​S402, according to the modal damping of the target battery pack and the vibration frequency spectrum loading curve, a random vibration simulation is performed on the simulation model of the target battery pack to obtain a current simulation result corresponding to the random vibration simulation.

[0094] Specifically, the modal damping of the battery pack and the vibration frequency spectrum loading curve received by the battery pack are set, and then random vibration simulation analysis is submitted to perform random vibration simulation.

[0095] Optionally, in another embodiment of the present application, when the target simulation item is a bottom ball impact simulation, a specific implementation of step S102, i.e., a specific implementation of the bottom ball impact simulation of the battery pack, as shown in Figure 5 , includes:

[0096] S501, for each ball impact combination, a simulation model corresponding to the ball impact combination is established based on the simulation model of the target battery pack, and a simulation initial boundary condition corresponding to the ball impact combination is set.

[0097] Among them, a ball impact combination includes an extrusion head of a certain shape and an extruded energy. Optionally, the ball impact combination can include: 120J energy D25 half ball head cylinder, 240J energy mountain-shaped extrusion head, 240J energy Ф10 flat head cylinder, 240J energy D25 half ball head cylinder. Of course, other combinations can also be set according to requirements.

[0098] S502, according to the simulation initial boundary condition corresponding to each ball impact combination, the bottom ball impact simulation of the battery pack is performed through the simulation model corresponding to each ball impact combination to obtain each current simulation result corresponding to the bottom ball impact simulation.

[0099] Optionally, in another embodiment of the present application, when the target simulation item is a cell swelling cycle life simulation, a specific implementation of step S102, i.e., a specific implementation of the cell swelling cycle life simulation of the battery pack, as shown in Figure 6 , includes:

[0100] S601, using the current simulation model of the target battery pack, the swelling force of a plurality of target components of the target battery pack during the charging and discharging process of the target battery pack is simulated.

[0101] Among them, the target component is a component that needs to be tested.

[0102] S602, according to the maximum swelling force and the minimum swelling force of each target component obtained by simulation, the stress amplitude suffered by each target component is calculated.

[0103] Wherein, the maximum expansion force is the expansion force when the battery has the maximum electricity, usually the expansion force when the SOC is 100%. The minimum expansion force is the expansion force when the battery has the minimum electricity, usually the expansion force when the SOC is 3%. The stress amplitude can be obtained by subtracting the minimum expansion force from the maximum expansion force.

[0104] S603, determine the current simulation result corresponding to the battery cell expansion cycle life simulation by comparing the stress amplitude of each target component with the fatigue strength of the material of each target component.

[0105] Wherein, when the stress amplitude of the target component is less than the fatigue strength of the material of the target component, it is determined that the battery cell expansion cycle life simulation of the target component is qualified. Specifically, the simulation results of each target component can be combined to form the current simulation result corresponding to the battery cell expansion cycle life simulation. Alternatively, the current simulation result corresponding to the battery cell expansion cycle life simulation can be determined according to the simulation results of each target component, for example, if the simulation results of each target component are all qualified, it is determined that the current simulation result corresponding to the battery cell expansion cycle life simulation is qualified. If the simulation result of any target component is not qualified, it is determined that the current simulation result corresponding to the battery cell expansion cycle life simulation is not qualified.

[0106] Alternatively, in another embodiment of the present application, when the target simulation item is the bonding performance simulation, one specific implementation of step S102, i.e. one specific implementation of the bonding performance simulation of the battery pack, as shown in Figure 7 includes:

[0107] S701, set the expansion coefficient and the initial temperature on the simulation model of the target battery pack.

[0108] S702, perform expansion force simulation and mechanical impact simulation using the simulation model of the target battery pack, and obtain the stress of each bonding interface of the target battery pack.

[0109] Wherein, each bonding interface can be all bonding interfaces, or a few most important bonding interfaces, or the weakest bonding interface.

[0110] Specifically, a changing temperature curve is loaded on the battery cell to simulate the thermal expansion process of the whole battery pack. When the battery cell reaches the expected maximum expansion force, the expansion force simulation condition is stopped, and under the premise of applying the maximum restraint force of the physical field to the beam of the battery pack at the maximum expansion force condition, the impact curve required by the national standard or the enterprise standard is set to perform mechanical impact simulation analysis.

[0111] S703, compare the maximum stress in the stress of each bonding interface with the bonding peel strength of the bonding glue of each bonding interface respectively, and determine the current simulation result corresponding to each bonding interface.

[0112] S704, calculate the stress average of each bonding interface, and determine the adhesive failure degree of each bonding interface according to the stress average of each bonding interface.

[0113] S103, judge whether the current simulation results corresponding to each target simulation item are qualified.

[0114] If it is judged that the current simulation results corresponding to any one target simulation item are not qualified, it means that there is still a safety problem, so the step S104 is performed at this time. If it is judged that the current simulation results corresponding to each target simulation item are qualified, the step S105 can be performed.

[0115] S104, optimize the simulation model of the current target battery pack.

[0116] Specifically, the design of the target battery pack can be adjusted according to the qualified target simulation item, and then the simulation model of the current target battery pack is optimized according to the design adjustment.

[0117] It should be noted that after the step S104 is performed, since the design of the target battery pack is adjusted, in order to verify the structural safety of the adjusted target battery, the simulation model of the optimized target battery pack is returned to perform the step S102 at this time.

[0118] S105, end the simulation of the target battery pack.

[0119] Since the target battery pack at this time passes the verification of each target simulation item, the parameters of the simulation model of the current target battery pack can be outputted to generate the target battery pack according to these parameters.

[0120] The embodiment of the application provides a battery pack structure safety verification method, a mechanical model of a target battery pack is modeled, and a simulation model of the target battery pack is obtained. The simulation model of the target battery pack includes a box main body structure system model, a cell system model, an electrical system model and a thermal management system model of the target battery pack, so that a complete battery pack model is constructed, and the conditions of each system in the verification process are facilitated to be determined subsequently. Then, for each target simulation item, the simulation of the target simulation item is performed by using the simulation model of the current target battery pack, and the current simulation result corresponding to the target simulation item is obtained. The target simulation item includes modal simulation, random vibration simulation, bottom ball impact simulation, cell swelling cycle life simulation and bonding performance simulation. The modal simulation is performed by taking the simulation result of the target prestress as the initial physical field boundary condition of the modal simulation. The target prestress is the counter-pressing force of the battery pack box frame structure to the cell surface after being pressed by the cell module swelling force. The random vibration simulation is performed by taking the structural damping and material damping as the modal damping of the battery pack. The bottom ball impact simulation includes the simulation of the bottom ball impact of the battery pack by using the extrusion heads with different energy and shapes. The cell swelling cycle life simulation simulates the fatigue strength of a plurality of specified components in the battery pack when the swelling force cyclically changes in the battery charging and discharging process. The bonding performance simulation simulates the bonding performance of each bonding interface in the battery pack under the swelling and mechanical impact of the battery pack, so that the comprehensive simulation verification of the target battery pack is realized. Then, it is judged whether the current simulation results corresponding to each target simulation item are all qualified. If it is judged that the current simulation result corresponding to any one target simulation item is unqualified, the simulation model of the current target battery pack is optimized, and the simulation of the target simulation item is performed by using the simulation model of the optimized target battery pack, so that the current simulation result corresponding to the target simulation item is obtained, so that the battery design can be continuously optimized until it passes the safety verification. If it is judged that the current simulation results corresponding to each target simulation item are all qualified, the simulation of the target battery pack is ended, so that the modal simulation, the random vibration simulation, the bottom ball impact simulation, the cell swelling cycle life simulation and the bonding performance simulation of the battery are performed by using the constructed simulation model of the battery pack, the safety of the structure of the battery pack can be comprehensively verified without constructing the battery pack sample, the development efficiency of the battery is effectively improved, and the safety of the structure of the developed battery pack is ensured.

[0121] It should be noted that the various target simulation items in the present application have an internal relationship and depend on each other. The modal simulation provides a basis for the random vibration simulation; the bonding performance simulation can ensure the overall stiffness of the battery pack, so that each component remains relatively stable during the impact process, reduces local stress concentration, and improves the impact resistance of the battery pack. In the bottom ball impact process, the bonding layer will participate in energy absorption and transmission. If the bonding performance is poor, part of the energy may be concentrated at the bonding interface, increasing the risk of damage to the bonding layer, and thus affecting the overall performance of the battery pack. The two can be verified and calibrated with each other; the cell swelling cycle life simulation can provide dynamic data of cell swelling for the prestress simulation, and the prestress simulation can verify the influence of cell swelling on the battery pack structure. The two complement each other and jointly guide the design and optimization of the battery pack. In actual application, the prestress simulation can be performed first to determine the prestress distribution of the structure; then the random vibration simulation is performed to analyze the performance of the battery pack in the vibration environment; then the bottom ball impact simulation is performed to ensure the safety of the battery pack when it is impacted; at the same time, the cell swelling cycle life simulation is performed to predict the life of the battery; finally, the bonding performance simulation is performed to evaluate the performance of the bonding agent in the battery pack. In this way, the simulation efficiency, as well as the reliability and safety of the battery pack simulation, can be improved.

[0122] Another embodiment of the present application provides a battery pack structure safety verification device, as shown in the accompanying drawings, comprising: Figure 8

[0123] The modeling unit 801 is configured to model the target battery pack as a mechanical model to obtain a simulation model of the target battery pack.

[0124] The simulation model of the target battery pack includes a box body structure system model, a cell system model, an electrical system model, and a thermal management system model of the target battery pack.

[0125] The simulation unit 802 is configured to perform simulation of each target simulation item by using the current simulation model of the target battery pack to obtain a current simulation result corresponding to the target simulation item.

[0126] ​The target simulation items include modal simulation, random vibration simulation, bottom ball impact simulation, cell swelling cycle life simulation, and bonding performance simulation. The modal simulation is performed by taking the simulation result of the target prestress as the initial physical field boundary condition of the modal simulation. The target prestress is the reaction compression force on the cell surface generated by the battery pack box frame structure after being pressed by the cell module swelling force. The random vibration simulation is performed by taking the structural damping and material damping as the modal damping of the battery pack. The bottom ball impact simulation includes the simulation of the ball impact on the bottom of the battery pack by using multiple extrusion heads with different energy and shapes. The cell swelling cycle life simulation simulates the fatigue strength of multiple specified components in the battery pack when the swelling force cyclically changes during the battery charging and discharging process. The bonding performance simulation simulates the bonding performance of each bonding interface in the battery pack under the battery swelling and mechanical impact.

[0127] The judgment unit 803 is configured to judge whether the current simulation results corresponding to each target simulation item are all qualified.

[0128] The optimization unit 804 is configured to, when it is judged that the current simulation result corresponding to any one target simulation item is unqualified, optimize the simulation model of the current target battery pack, and return the simulation unit to perform the simulation of each target simulation item by using the simulation model of the optimized target battery pack to obtain the current simulation result corresponding to the target simulation item.

[0129] The ending unit 805 is configured to, when it is judged that the current simulation results corresponding to each target simulation item are all qualified, end the simulation of the target battery pack.

[0130] Optionally, in the battery pack structure safety verification device provided in another embodiment of the present application, the modeling unit comprises:

[0131] The box modeling unit is configured to remove the small chamfers on the main body structure of the target battery pack by geometric cleaning, extract the middle surface of the sheet metal part, establish a weld according to the welding position, and set a regular circular hole grid in the locking area of the bolt, to obtain the main body structure system model of the target battery pack.

[0132] The cell modeling unit is configured to establish the model of each component of the cell of the target battery pack, simulate the mechanical assembly connection relationship between each component, and obtain the cell system model of the target battery pack.

[0133] The electrical modeling unit is configured to perform three-dimensional tetrahedral solid modeling on the solid model of each electrical component of the target battery pack, to obtain the model of each electrical component, extract the middle surface of each type of electrical connector, and simulate the mechanical assembly by motion coupling constraint, to obtain the electrical system model of the target battery pack.

[0134] The management system modeling unit is configured to perform shell extraction on the cold plate of the target battery pack, plan feature lines of flow channels, non-flow channels and brazing areas, and perform entity modeling on the foam, structural adhesive and thermal conductive adhesive of the thermal management system to obtain a thermal management system model of the target battery pack.

[0135] The connection unit is configured to simulate the connection relationship between the thermal management system of the target battery pack and the main body structure system of the box according to the installation process of the cold plate of the target battery pack.

[0136] Optionally, in the battery pack structure safety verification device provided in another embodiment of the present application, when the target simulation item is modal simulation, the simulation unit is configured to:

[0137] perform simulation analysis on the target pre-stress under the assembly simulation working condition containing the target pre-stress.

[0138] On the basis of the physical field obtained by completing the simulation analysis on the target pre-stress, modal simulation analysis is performed on the simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item.

[0139] Optionally, in the battery pack structure safety verification device provided in another embodiment of the present application, when the target simulation item is random vibration simulation, the simulation unit is configured to:

[0140] set the structural damping of the target battery pack and the material damping of the components as the modal damping of the target battery pack, and set the vibration frequency spectrum loading curve of the target battery pack.

[0141] According to the modal damping and the vibration frequency spectrum loading curve of the target battery pack, random vibration simulation is performed on the simulation model of the target battery pack to obtain the current simulation result corresponding to the random vibration simulation.

[0142] Optionally, in the battery pack structure safety verification device provided in another embodiment of the present application, when the target simulation item is bottom ball impact simulation, the simulation unit is configured to:

[0143] For each ball impact combination, a simulation model corresponding to the ball impact combination is established on the basis of the simulation model of the target battery pack, and a simulation initial boundary condition corresponding to the ball impact combination is set. One ball impact combination includes an extrusion head with a certain shape and an extrusion energy.

[0144] According to the simulation initial boundary condition corresponding to each ball impact combination, battery pack bottom ball impact simulation is performed through the simulation model corresponding to each ball impact combination to obtain each current simulation result corresponding to the bottom ball impact simulation.

[0145] Optionally, in the battery pack structure safety verification device provided in another embodiment of the present application, when the target simulation item is cell swelling cycle life simulation, the simulation unit is configured to:

[0146] The expansion forces of the plurality of target components of the target battery pack during the charging and discharging process of the target battery pack are simulated by using the simulation model of the target battery pack.

[0147] The stress amplitudes of the target components are calculated according to the maximum expansion force and the minimum expansion force of each target component obtained by simulation.

[0148] The current simulation result corresponding to the simulation of the cycle life of the cell expansion is determined by comparing the stress amplitude of each target component with the fatigue strength of the material of each target component.

[0149] Optionally, in the battery pack structure safety verification device provided by another embodiment of the present application, when the target simulation item is the bonding performance simulation, the simulation unit is configured to:

[0150] The expansion coefficient and the initial temperature are set on the simulation model of the target battery pack.

[0151] The expansion force simulation and the mechanical impact simulation are performed by using the simulation model of the target battery pack, and the stress of each bonding interface of the target battery pack is obtained.

[0152] The maximum stress in the stress of each bonding interface is compared with the bonding peel strength of the bonding glue of each bonding interface to determine the current simulation result corresponding to each bonding interface.

[0153] The stress average of each bonding interface is calculated, and the glue failure degree of each bonding interface is determined according to the stress average of each bonding interface.

[0154] It should be noted that the specific working process of each unit provided by the above embodiments of the present application can be correspondingly referred to the implementation process of the corresponding steps in the above method embodiments, which will not be described here.

[0155] Another embodiment of the present application provides an electronic device, as shown in the figure, comprising: Figure 9

[0156] The memory 901 and the processor 902.

[0157] The memory 901 is configured to store a program.

[0158] The processor 902 is configured to execute the program stored in the memory 901, and the program is executed to implement the battery pack structure safety verification method provided by any one of the above embodiments.

[0159] ​Another embodiment of the present application provides a computer storage medium for storing a computer program, which, when executed by a processor, is used to implement the battery pack structure safety verification method according to any one of the above.

[0160] Computer storage media includes permanent and non-permanent, removable and non-removable media, which can be implemented by any method or technology to store information. The information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device. According to the definition herein, computer readable media does not include transitory computer readable media, such as modulated data signals and carriers.

[0161] The skilled person can further realize that the units and algorithm steps of various examples described in connection with the embodiments disclosed herein can be realized in electronic hardware, computer software, or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of various examples have been described in general terms above. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0162] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery pack structure safety verification method, characterized by, The method comprises the following steps: S101, modeling a target battery pack by a mechanical model to obtain a simulation model of the target battery pack; wherein the simulation model of the target battery pack comprises a box body structure system model, a cell system model, an electrical system model and a thermal management system model of the target battery pack; S102, for each target simulation item, performing simulation of the target simulation item by using the current simulation model of the target battery pack to obtain a current simulation result corresponding to the target simulation item; wherein the target simulation item comprises modal simulation, random vibration simulation, bottom ball impact simulation, cell swelling cycle life simulation and bonding performance simulation; the modal simulation is performed with the simulation result of a target prestress as the initial physical field boundary condition of the modal simulation; the target prestress is the counter-pressing force of the battery pack box frame structure after being pressed by the cell module swelling force; the random vibration simulation is performed with structural damping and material damping as the modal damping of the battery pack; the bottom ball impact simulation comprises simulation of ball impact on the bottom of the battery pack by using multiple extrusion heads with different energy and shapes; the cell swelling cycle life simulation simulates the fatigue strength of multiple specified components in the battery pack when the swelling force cyclically changes during the battery charging and discharging process; the bonding performance simulation simulates the bonding performance of each bonding interface in the battery pack under the swelling and mechanical impact of the battery pack; S103, judging whether the current simulation results corresponding to each target simulation item are all qualified; S104, if it is judged that the current simulation result corresponding to any one of the target simulation items is unqualified, optimizing the current simulation model of the target battery pack, and returning to perform the simulation of each target simulation item by using the optimized simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item; S105, if it is judged that the current simulation results corresponding to each target simulation item are all qualified, ending the simulation of the target battery pack.

2. The method of claim 1, wherein, The modeling of the target battery pack by the mechanical model to obtain the simulation model of the target battery pack comprises: S201, removing the micro chamfer on the box body structure of the target battery pack by geometric cleaning, extracting the middle surface of the sheet metal part, establishing a weld according to the welding position, and setting a regular circular hole grid in the locking area of the bolt to obtain the box body structure system model of the target battery pack; S202, establishing the model of each component of the cell of the target battery pack, and simulating the mechanical assembly connection relationship between each component to obtain the cell system model of the target battery pack; S203, performing three-dimensional tetrahedral solid modeling on each electrical part of the target battery pack after real block digital modeling, obtaining the model of each electrical part, and extracting the middle surface of each type of electrical connector and simulating mechanical assembly by motion coupling constraint to obtain the electrical system model of the target battery pack; S204, the cold plate of the target battery pack is taken out of the shell, and the feature lines of the flow channel, the non-flow channel, and the brazing area are planned, and the foam, structural adhesive, and thermal conductive adhesive of the thermal management system are physically modeled to obtain a thermal management system model of the target battery pack; S205, according to the installation process of the cold plate of the target battery pack, the connection relationship between the thermal management system of the target battery and the main body structure system of the box is simulated.

3. The method of claim 1, wherein, When the target simulation item is the modal simulation, the simulation of the target simulation item is performed by using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item, which includes: S301, performing simulation analysis of the target prestress on the assembly simulation working condition containing the target prestress; S302, based on the physical field obtained by completing the simulation analysis of the target prestress, performing modal simulation analysis on the simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item.

4. The method of claim 1, wherein, When the target simulation item is the random vibration simulation, the simulation of the target simulation item is performed by using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item, which includes: S401, setting the structural damping of the target battery pack and the material damping of the components as the modal damping of the target battery pack, and setting the vibration frequency spectrum loading curve of the target battery pack; S402, according to the modal damping and the vibration frequency spectrum loading curve of the target battery pack, performing random vibration simulation by using the simulation model of the target battery pack to obtain the current simulation result corresponding to the random vibration simulation.

5. The method of claim 1, wherein, When the target simulation item is the bottom ball strike simulation, the simulation of the target simulation item is performed by using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item, which includes: S501, for each ball strike combination, respectively, on the basis of the simulation model of the target battery pack, a simulation model corresponding to the ball strike combination is established, and a simulation initial boundary condition corresponding to the ball strike combination is set; wherein one ball strike combination includes an extrusion head of one shape and an extruded energy; S502, according to the simulation initial boundary condition corresponding to each ball strike combination, the battery pack bottom ball strike simulation is performed by using the simulation model corresponding to each ball strike combination to obtain each current simulation result corresponding to the bottom ball strike simulation.

6. The method of claim 1, wherein, When the target simulation item is the cell swelling cycle life simulation, the simulation of the target simulation item is performed by using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item, which includes: S601, using the current simulation model of the target battery pack, simulating the swelling force of a plurality of target components of the target battery pack during the charging and discharging process of the target battery pack; S602, according to the maximum swelling force and the minimum swelling force of each target component obtained by simulation, the stress amplitude suffered by each target component is calculated. S603, determine the current simulation result corresponding to the cycle life simulation of the battery cell expansion by comparing the stress amplitude of each target component with the fatigue strength of the material of each target component.

7. The method of claim 1, wherein, When the target simulation item is the bonding performance simulation, the simulation of the target simulation item by using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item, includes: S701, set the expansion coefficient and the initial temperature on the simulation model of the target battery pack; S702, perform expansion force simulation and mechanical impact simulation by using the simulation model of the target battery pack, and obtain the stress of each bonding interface of the target battery pack; S703, compare the maximum stress in the stress of each bonding interface with the bonding peel strength of the bonding glue of each bonding interface respectively, and determine the current simulation result corresponding to each bonding interface; S704, calculate the average stress of each bonding interface, and determine the glue failure degree of each bonding interface according to the average stress of each bonding interface.

8. A battery pack structure safety verification apparatus characterized by comprising: It includes: The modeling unit is used for modeling the target battery pack to obtain the simulation model of the target battery pack; wherein the simulation model of the target battery pack includes the main structure system model of the battery pack, the cell system model, the electrical system model and the thermal management system model of the target battery pack; The simulation unit is used for respectively for each target simulation item, the simulation of the target simulation item by using the current simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item; wherein the target simulation item includes modal simulation, random vibration simulation, bottom ball impact simulation, cycle life simulation of battery cell expansion, bonding performance simulation; the modal simulation is carried out with the simulation result of the target pre-stress as the initial physical field boundary condition of modal simulation; the target pre-stress is the counter pressure of the battery pack box frame structure after being extruded by the battery cell module expansion force; the random vibration simulation is carried out with the structural damping and material damping as the modal damping of the battery pack; the bottom ball impact simulation includes the simulation of the bottom of the battery pack by using the extrusion head with different energy and various shapes; the cycle life simulation of battery cell expansion simulates the fatigue strength of multiple specified components in the battery pack when the expansion force cycles change during the battery charging and discharging process; the bonding performance simulation simulates the bonding performance of each bonding interface in the battery pack under the expansion and mechanical impact of the battery pack; The judgment unit is used for judging whether the current simulation result corresponding to each target simulation item is qualified or not; The optimization unit is used for optimizing the simulation model of the target battery pack when it is judged that the current simulation result corresponding to any one of the target simulation items is unqualified, and returning the simulation unit to execute the simulation of the target simulation item by using the simulation model of the target battery pack to obtain the current simulation result corresponding to the target simulation item after optimization. A termination unit is configured to terminate the simulation of the target battery pack when it is determined that the current simulation results corresponding to each of the target simulation items are all qualified.

9. An electronic device, comprising: Comprise: A memory and a processor; The memory is configured to store a program; The processor is configured to execute the program, and the program, when executed, is specifically configured to implement the battery pack structure safety verification method in any one of claims 1 to 7.

10. A computer storage medium, characterized in that, A computer program is stored, and the computer program, when executed by a processor, is configured to implement the battery pack structure safety verification method in any one of claims 1 to 7.

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