A design method and system for explosion-proof power battery pack

Abstract

The present invention relates to the technical field of battery structure design, and specifically to a design method and system for an explosion-proof power battery pack. The method of this scheme first creates a first finite element model based on the CAD geometric model of the battery pack, and then performs a topological optimization analysis on the first finite element model to obtain the arrangement and position of the reinforcement ribs on the outer surface of the battery pack frame, and then performs a size optimization analysis on the first finite element model to determine the parameters of the battery pack components and obtain the optimal component thickness size, so as to design the battery pack structure. By adopting the above scheme of the present application, it can be ensured that the battery pack structure design is lightweight while meeting the explosion-proof performance, which can not only reduce the manufacturing cost of the power battery pack, but also reduce the weight and improve the vehicle-related performance.

Description

Technical Field

[0001] The present invention relates to the technical field of battery structure design, and in particular to a design method and system for an explosion-proof power battery pack. Background Art

[0002] Developing new energy vehicles is one of the important means to ease energy pressure and reduce environmental pollution. For new energy vehicles, the power battery pack is its key core component, and its performance affects driving safety and driving range. At present, the volume and weight of the explosion-proof power battery pack of mining new energy vehicles are generally large. Under the premise that the battery module and its core are difficult to change, it is particularly important to optimize the lightweight design of its frame structure.

[0003] At present, the structural design of explosion-proof power battery packs for mining is mainly designed based on human experience. For example, the position and size of the reinforcing ribs on the external shell are determined manually based on experience. In order to meet the explosion-proof requirements, the battery pack frame structure is designed to be thicker, resulting in a larger overall mass of the battery pack frame structure and a large redundancy in the structural design. Summary of the invention

[0004] The present invention provides a method and system for designing an explosion-proof power battery pack, which effectively solves the problem in the prior art that the structure design of the explosion-proof power battery pack for mining is heavy, has large redundancy, and leads to large overall quality.

[0005] According to the first aspect, an embodiment provides a method for designing an explosion-proof power battery pack, including:

[0006] Get the CAD geometric model of the battery pack;

[0007] Establishing a first finite element model of the battery pack according to the CAD geometric model;

[0008] Performing a topology optimization analysis on the first finite element model to obtain a first analysis result;

[0009] Performing a first round of reconstruction on the CAD geometric model of the battery pack according to the first analysis result, and creating a second finite element model according to the CAD geometric model reconstructed in the first round;

[0010] Performing a size optimization analysis on the second finite element model to obtain a second analysis result;

[0011] A component size design plan for the battery pack is determined based on the second analysis result.

[0012] In an achievable implementation, after obtaining the second analysis result, the method further includes:

[0013] Performing a second round of reconstruction on the CAD geometric model reconstructed in the first round according to the second analysis result, and creating a third finite element model according to the CAD geometric model reconstructed in the second round;

[0014] The third finite element model is subjected to static pressure condition analysis and verification to determine whether the maximum structural stress in the third finite element model is less than the material yield strength. If so, the optimization is completed; otherwise, the second finite element model is subjected to size optimization analysis again.

[0015] In an achievable implementation, establishing a first finite element model of the battery pack according to the CAD geometric model includes:

[0016] Filling the CAD geometric model of the battery pack with structural materials;

[0017] A first finite element model of the battery pack is established based on the CAD geometric model after the structural material is filled.

[0018] In an achievable implementation, performing topology optimization analysis on the first finite element model to obtain a first analysis result includes:

[0019] Performing topology optimization analysis on the first finite element model through a density-stiffness interpolation model to obtain a first analysis result;

[0020] After obtaining the first analysis result, the method further includes:

[0021] The arrangement position, size, thickness and quantity of the reinforcing rib structure on the shell of the battery pack are determined according to the first analysis result.

[0022] In an achievable implementation, the first round of reconstruction of the CAD geometric model of the battery pack according to the first analysis result includes:

[0023] Designing a reinforcing rib structure on the shell of the battery pack;

[0024] The first round of reconstruction is performed on the CAD geometric model of the battery pack based on the designed reinforcing rib structure.

[0025] In an achievable implementation manner, performing size optimization analysis on the second finite element model to obtain a second analysis result includes:

[0026] The second finite element model is subjected to size optimization analysis by means of a random sampling high-dimensional model representation method to obtain a second analysis result.

[0027] According to the second aspect, an embodiment provides a design system for an explosion-proof power battery pack, including:

[0028] An acquisition module is used to acquire the CAD geometric model of the battery pack;

[0029] A first creation module, configured to establish a first finite element model of the battery pack according to the CAD geometric model;

[0030] A topology optimization analysis module, used to perform topology optimization analysis on the first finite element model to obtain a first analysis result;

[0031] A second creation module, configured to perform a first round of reconstruction on the CAD geometric model of the battery pack according to the first analysis result, and create a second finite element model according to the CAD geometric model reconstructed in the first round;

[0032] A size optimization analysis module, used for performing size optimization analysis on the second finite element model to obtain a second analysis result;

[0033] The scheme design module is used to receive the user's input operation based on the second analysis result to obtain the component size design scheme of the battery pack.

[0034] In an achievable implementation, the system further includes a third creation module and a verification module;

[0035] The third creation module is used to perform a second round of reconstruction on the CAD geometric model reconstructed in the first round according to the second analysis result, and create a third finite element model according to the CAD geometric model reconstructed in the second round;

[0036] The verification module is used to perform static pressure condition analysis and verification on the third finite element model to determine whether the maximum structural stress in the third finite element model is less than the material yield strength. If so, the optimization is completed; otherwise, the size optimization analysis of the second finite element model is re-performed.

[0037] In an achievable implementation, the first creation module includes:

[0038] A filling unit, used to fill the CAD geometric model of the battery pack with structural materials;

[0039] A creation unit is used to establish a first finite element model of the battery pack according to the CAD geometric model after the structural material is filled.

[0040] According to a third aspect, an embodiment provides a computer-readable storage medium, on which a program is stored, and the program can be executed by a processor to implement the method as described above.

[0041] According to the above-mentioned embodiment, a method / system for designing an explosion-proof power battery pack is first created based on the CAD geometric model of the battery pack, and then a topological optimization analysis is performed on the first finite element model to obtain the arrangement and position of the reinforcement ribs on the outer surface of the battery pack frame, and then a size optimization analysis is performed on the first finite element model to determine the parameters of the battery pack components and obtain the optimal component thickness size, so as to design the battery pack structure. By adopting the above-mentioned scheme of the present application, it is possible to ensure that the battery pack structure design is lightweight while meeting the explosion-proof performance, which can not only reduce the manufacturing cost of the power battery pack, but also reduce the weight and improve the vehicle-related performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The process of designing a method for an explosion-proof power battery pack provided in this embodiment is Figure 1 ;

[0043] Figure 2 The process of the design method of the explosion-proof power battery pack provided in this embodiment Figure 2 ;

[0044] Figure 3 A flowchart for creating a first finite element model provided for this embodiment;

[0045] Figure 4 A flowchart of performing topology optimization analysis on a first finite element model provided in this embodiment;

[0046] Figure 5 (a), (b), and (c) are CAD geometric models of the initial battery pack from different perspectives provided in this embodiment;

[0047] Figure 6 (a), (b), and (c) are respectively the outer contour envelope models of the battery pack at different viewing angles provided in this embodiment;

[0048] Figure 7 (a), (b), and (c) are CAD geometric models of the battery pack after the first round of reconstruction from different perspectives provided in this embodiment;

[0049] Figure 8 A schematic diagram of the structure of a design system for an explosion-proof power battery pack provided in this embodiment.

[0050] Figure numerals: 10, acquisition module; 20, first creation module; 30, topology optimization analysis module; 40, second creation module; 50, size optimization analysis module; 60, scheme design module. DETAILED DESCRIPTION

[0051] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0052] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0053] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0054] Since the market segment for mining new energy explosion-proof vehicles is relatively small, there are relatively few businesses that design mining explosion-proof power battery packs. The biggest difference between mining explosion-proof power battery packs and ordinary passenger car power battery packs is the explosion-proof requirements. Mining explosion-proof power battery packs must meet relevant standards, requiring the power source explosion-proof structure, performance and markings to meet the requirements of GB3836.1~4-2010, where the explosion-proof cavity where the battery is placed should be able to withstand a static pressure test of not less than 1.5MPa; that is, the battery module inside the power battery pack will not be permanently deformed after the explosion of the battery pack external frame structure, and the corresponding test is that the internal cavity of the battery pack should be able to withstand a static pressure test of not less than 1.5MPa; the specific operation of the static pressure test is to fill the empty battery pack structure without the battery module installed with water, and after filling with water, the water pressure is pressurized to 1.5MPa. Even if the inner surface of the battery pack is subjected to a uniform pressure of 1.5MPa, the battery pack will not leak after 10s and the frame structure will not be permanently deformed after the pressure is released, which means that the test has passed.

[0055] At present, the structural design of explosion-proof power battery packs for mining is mainly designed based on human experience. For example, the position and size of the reinforcing ribs on the external shell are determined by human experience. In order to meet the explosion-proof requirements, the battery pack frame structure is designed to be thicker, resulting in a larger overall mass of the battery pack frame structure, which affects the performance. In view of this, the present application proposes a design method and system for explosion-proof power battery packs to solve the problems existing in the above-mentioned prior art.

[0056] like Figure 1 As shown, this embodiment provides a design method for an explosion-proof power battery pack, comprising the following steps:

[0057] Step 100: Obtain the CAD geometric model of the battery pack through the acquisition module. Figure 5 The CAD geometric model of the battery pack obtained in this step is the CAD geometric model of the initial battery pack.

[0058] Step 200: Create a first finite element model of the battery pack according to the CAD geometric model through a first creation module. Specifically, a roughened finite element model of the battery pack, i.e., the first finite element model, is created according to the initial CAD geometric model of the battery pack. Figure 3 As shown, the specific steps include:

[0059] Step 201: Fill the CAD geometric model of the battery pack with structural materials.

[0060] Step 202: Establish a first finite element model of the battery pack according to the CAD geometric model filled with structural materials.

[0061] Specifically, for Figure 5 (a) Figure 5 (b) Figure 5 The geometric model of the initial battery pack shown in (c) is used to create a corresponding CAE finite element model, and a simulation analysis of the static pressure condition is performed. The weight reduction optimization design space is evaluated based on the simulation results of the initial structural strength of the battery pack. Among them, the static pressure condition refers to the requirement that the mining battery pack must meet the "Technical Requirements for Safety of Mining Explosion-proof Lithium-ion Battery Power Sources (Trial)" (No.: AQYQ-AAC-2021-01), which stipulates that the battery module inside the battery pack will not be permanently deformed after the explosion of the battery pack external structure. The corresponding test is that the internal cavity of the battery pack should be able to withstand a static pressure test requirement of not less than 1.5MPa. The evaluation standard of the CAE simulation results is that the maximum structural stress does not exceed the yield strength of the battery pack material of 1200MPa.

[0062] As a specific implementation method of this embodiment, after the first finite element model is created, an initial static pressure condition simulation analysis is performed on the first finite element model. According to the initial static pressure condition simulation analysis, the maximum stress of the original structure is 755MPa, which is much smaller than the material yield strength of 1200MPa. It is judged that the static pressure condition meets the strength requirements and there is a large margin. Therefore, there is a large room for weight reduction optimization and further lightweight design.

[0063] Then, the external structural material is filled into the initial battery pack CAD geometric model, and the outer contour of the original battery pack is enveloping to form the following Figure 6 (a) Figure 6 (b) Figure 6 The new geometric model shown in (c) in the figure has the internal cavity structure unchanged, and the entire battery pack is basically simplified into a cube from the external perspective. Then, a CAE finite element model is created for the simplified cube, i.e., the outer contour envelope model, to obtain the first finite element model.

[0064] Step 300: Perform topology optimization analysis on the first finite element model through the topology optimization analysis module to obtain the first analysis result. Based on the static pressure analysis condition, the SIMP method is used to create optimization variables, optimization constraints and optimization targets for the battery pack finite element model (i.e., the first finite element model) and perform topology optimization analysis. The density of the battery pack material can be optimized through topology optimization analysis, and the density of the unit with less impact on the static pressure analysis is reduced to 0, that is, the unit is deleted. Finally, the optimal material distribution is formed through multiple rounds of iterations. According to the optimal material distribution, it can be determined which positions have a higher density, that is, reinforcing ribs need to be arranged at these positions.

[0065] like Figure 4 As shown, the specific steps include:

[0066] Step 301: Perform topology optimization analysis on a first finite element model using a density-stiffness interpolation model to obtain a first analysis result.

[0067] After obtaining the first analysis result, the method further includes step 302: determining the arrangement position, size, thickness and quantity of the reinforcing rib structure on the shell of the battery pack according to the first analysis result.

[0068] Topology optimization is a mathematical method that optimizes the distribution of materials in a given area according to given load conditions, constraints and performance indicators, also known as structural layout optimization. With material distribution as the optimization object, through topology optimization, the best material distribution scheme can be found in the design space of uniformly distributed materials. The topology optimization analysis in this step mainly performs topology optimization on the rib area around the outside of the battery pack. The purpose is to find the best arrangement of the ribs around it, including size, position, quantity, etc., while meeting the requirements of static pressure analysis. Therefore, before performing topology optimization, the geometric model of the battery pack should be filled, the rib structure around the original outer surface should be deleted, and the surrounding space should be filled with materials to a height that is the same as the original rib height, forming an outer contour envelope model of the battery pack, which is equivalent to thickening the shell thickness around it without any ribs. Then, a corresponding CAE roughened finite element model is created for this outer contour envelope CAD model of the battery pack for subsequent topology optimization analysis.

[0069] Specifically, the variable density method is an effective method for solving the topology optimization of continuum structures. This method introduces an imaginary material whose density is variable. The relationship between material parameters and material density is also artificially assumed. Density is taken as the design variable during topology optimization design. The optimization result is the optimal distribution of the material, that is, the optimal topology of the structure. This optimization adopts the Solid Isotropic Material with Penalization model (SIMP), which is a density-stiffness interpolation model commonly used in topology optimization problems. This model assumes that the material density is a constant within the unit and is used as a design variable. The material properties are simulated using an exponential function of the unit density, which has the advantages of simple calculation and high efficiency.

[0070] The specific steps of topology optimization analysis are as follows: (1) Define the design domain, specify the optimization and non-optimization areas, define the optimization design constraints, boundary conditions such as loads, and the optimized material volume fraction. The relative density of the units in the design domain can change with the iteration process, while the relative density of the units in the non-design domain is constant; (2) Based on the finite element mesh of the design domain, calculate the unit stiffness matrix before optimization; (3) Initialize the unit design variables, that is, give each unit in the design domain an initial relative density; (4) Calculate the material property parameters of each discrete unit, calculate the unit stiffness matrix, assemble the total stiffness matrix of the structure, and calculate the node displacement; (5) Calculate the strain energy and sensitivity of the overall structure and solve the Lagrangian factor; (6) Apply the optimization criterion method based on SIMP weighted strain energy minimization to iterate the design variables, including the iteration of the Lagrangian factor. The Lagrangian factor at this time is related to the volume constraint; (7) Check whether the volume constraint is satisfied. If not, return to step 6 for iterative calculation. If satisfied, continue; (8) After each unit iteration, a new set of iterative values ​​of the design variables is obtained; (9) Check the convergence of the results. If not, go to step 4 for loop iteration. If converged, continue to the next step. The convergence check can be carried out by the following method: taking the maximum components of two adjacent design variables respectively, and using the absolute difference between the two components as the criterion, or using the absolute difference between two adjacent design objective functions as the criterion; (10) generating the optimal topological form of the structure.

[0071] The optimization design domain of the topology optimization analysis is the structural filling area to which the reinforcement ribs on the outer surface of the original battery pack belong, that is, only the outer filling area is optimized, the optimization design variable is the unit density of the design domain, the optimization constraint is that the volume fraction is reduced by no less than 70%, and the optimization goal is to minimize the static strain energy of the overall structure. Through topology optimization analysis, the unit density of the battery pack design domain can be optimized. Under the condition of meeting the optimization goal, the unit density with less influence on the static pressure analysis is reduced to 0, that is, the unit is deleted, and the unit density with greater influence is 1, that is, the unit is retained; finally, the optimal unit density distribution is formed through multiple rounds of iterations. According to the optimal unit distribution, it can be determined which positions have a larger unit density, that is, it is necessary to arrange reinforcement ribs at this position.

[0072] According to the topology optimization results, areas with higher unit density can be obtained. Based on the area of ​​these areas and taking into account the processing requirements of parts, the layout position of the reinforcement ribs as well as the size, thickness and quantity of the reinforcement ribs can be preliminarily determined.

[0073] Step 400: The second creation module performs a first round of reconstruction on the CAD geometric model of the battery pack according to the first analysis result, and creates a second finite element model according to the CAD geometric model reconstructed in the first round.

[0074] Among them, the first round of reconstruction of the CAD geometric model of the battery pack is performed according to the first analysis result, specifically including: designing the reinforcing rib structure on the shell of the battery pack; and performing the first round of reconstruction of the CAD geometric model of the battery pack according to the designed reinforcing rib structure.

[0075] Based on the topology optimization analysis results, the new rib structure is dimensionally designed while meeting the requirements of component processing technology, and then the initial battery pack CAD geometric model is reconstructed to form the following Figure 7 (a) Figure 7 (b) Figure 7 The new power battery pack CAD structural geometry model shown in (c).

[0076] After forming a new CAD structural geometry model of the power battery pack, a corresponding second finite element model is created based on the model, and a static pressure condition analysis is performed on it. The evaluation criteria for the simulation results are that the maximum stress of the structure does not exceed the yield strength of the battery pack material of 1200MPa; the maximum stress of the reconstructed battery pack structure is 915MPa, which is still less than the material yield strength. The static pressure condition meets the analysis requirements, and there is room for further weight reduction optimization, so subsequent lightweight design, namely size optimization analysis, can be further performed. In addition, even if the reconstructed results do not meet the stress requirements, subsequent size optimization analysis can still be performed. Through size optimization analysis, the optimal structural size combination solution that meets the stress requirements can be obtained.

[0077] Step 500: The size optimization analysis module performs size optimization analysis on the second finite element model to obtain a second analysis result. Specifically, the size optimization analysis is performed on the second finite element model by a random sampling high-dimensional model representation method to obtain the second analysis result.

[0078] The thickness of the parts to be optimized is taken as the design parameter, the structural mass is reduced by at least 20% as the optimization constraint, and the minimum structural stress is taken as the optimization goal. The size optimization analysis is carried out based on the random sampling high-dimensional model representation method (RS-HDMR). The optimal size combination scheme of the parts is obtained while meeting the requirements of explosion-proof performance, namely static pressure analysis.

[0079] As a specific implementation method, according to the actual parts processing technology and assembly requirements, the size design parameters of the battery pack are determined as the thickness of 12 parts, namely the top plate, bottom plate, left plate, right plate, top horizontal rib, top vertical rib, side horizontal rib, side vertical rib, bottom straight rib, front cavity cover, rear cavity cover and top cavity cover, i.e., the design variables. Among them, the optimization design range of 7 design parameters, namely, the top plate, bottom plate, left plate, right plate, front cavity cover, rear cavity cover and top cavity cover, is 0mm to 4mm, i.e., the thickness can be reduced by at least 0mm and at most 4mm; the optimization design range of 5 design parameters, namely, the top horizontal rib, top vertical rib, side horizontal rib, side vertical rib and bottom straight rib, is -0.5mm to 2mm, i.e., the thickness can be increased by at most 0.5mm and reduced by at most 2mm.

[0080] According to the optimization objectives and constraints, a result with minimum mass and stress that meets the requirements of static pressure analysis can be obtained through several rounds of optimization iterations.

[0081] After determining the required optimization design input, the RS-HDMR method is used to perform size optimization analysis based on the static pressure condition. The RS-HDMR method is a random sampling high-dimensional model representation method, a mathematical model modeling method, which converts complex high-dimensional problems into the sum of a series of low-dimensional problems through the construction of a hierarchical structure, and uses fewer sample points to obtain a higher-precision approximate model to improve the calculation efficiency. RS-HDMR is used to construct an approximate model of battery pack structural stress. Monte Carlo random sampling is performed on each design variable within its optimization design interval. The number of points is determined based on whether the required accuracy is achieved when constructing the approximate model. The true response value at the sample point is calculated through numerical simulation of the established finite element model. In order to ensure the approximate accuracy of the model, the approximate model is extended to the second-order term, and the maximum degree of the fitted polynomial is quadratic. The square of the relative error is used as an evaluation index to check the error between the constructed approximate model and the true response function. Through data analysis, it can be seen that RS-HDMR can reflect the characteristics of the true model under the condition of 600 training sample points, with high fitting accuracy and significantly reduced calculation time. Based on the analysis results of 600 samples, the optimal combination of design parameters that meets the optimization objectives and constraints can be obtained.

[0082] Step 600: The solution design module determines a component size design solution for the battery pack according to the second analysis result.

[0083] According to the size optimization analysis in the previous step, the optimal size combination solution can be obtained through multiple iterations. The final optimization results are as follows: the top plate is reduced by 1.5mm, the bottom plate is reduced by 2.4mm, the left plate is reduced by 2.8mm, the right plate is reduced by 2.6mm, the top transverse rib is reduced by 0.0mm, the top vertical rib is reduced by 0.5mm, the side transverse rib is reduced by 0.7mm, the side vertical rib is increased by 0.2mm, the bottom straight rib is reduced by 0.0mm, the front cavity cover is reduced by 4.3mm, the rear cavity cover is reduced by 3.2mm, and the top cavity cover is reduced by 2.8mm. The maximum stress of the optimized structure is 1091MPa, which is less than the material yield strength of 1200MPa, and the static pressure condition meets the analysis requirements. The total mass of the battery pack can be reduced by 139.7kg. Compared with the original weight of 587kg, the overall weight of the battery pack structure is reduced by 23.8%. Experiments have shown that the solution of this application can ensure that the battery pack structure design is lightweight while meeting the explosion-proof performance.

[0084] If the battery pack has not been optimized by CAE, the structural design will be relatively redundant, and there is a large space for lightweight design. Therefore, this application can ensure that the battery pack structure design is lightweight while meeting the explosion-proof performance through CAE optimization design, which can not only reduce the manufacturing cost of the power battery pack, but also reduce weight and improve vehicle-related performance.

[0085] In this embodiment, if the stress in the last step of the optimization iteration does not meet the analysis requirements of the static pressure condition, the following solution can be adopted. Figure 2 As shown, after obtaining the second analysis result, the design method of the explosion-proof power battery pack of this embodiment further includes the following steps:

[0086] Step 700: The third creation module performs a second round of reconstruction on the CAD geometric model reconstructed in the first round according to the second analysis result, and creates a third finite element model according to the CAD geometric model reconstructed in the second round.

[0087] Step 800: Perform static pressure condition analysis and verification on the third finite element model through the verification module to determine whether the maximum structural stress in the third finite element model is less than the material yield strength. If so, execute step 900 to confirm that the optimization is completed. Otherwise, return to step 500 and re-perform size optimization analysis on the second finite element model.

[0088] Based on the size optimization analysis results, while meeting the requirements of component processing technology and battery pack structure assembly, the third creation module reconstructs the CAD geometric model reconstructed in the first round according to the second analysis results to form a new battery pack CAD geometric model (that is, the CAD geometric model reconstructed in the second round). The new sizes of all optimized design components undergo thickness changes on the outer surface of the battery pack structure, that is, the internal cavity structure of the optimized battery pack does not produce volume changes, which can ensure that the installation space of internal parts is not affected.

[0089] Based on the second round of reconstructed CAD geometric model of the reconstructed battery pack, the corresponding CAE finite element model (i.e., the third finite element model) is recreated for subsequent static pressure condition verification through the verification module.

[0090] The verification module performs static pressure condition analysis on the third finite element model to check whether the reconstructed structure meets the static pressure condition requirements. The static pressure analysis shows that the maximum stress of the battery pack is 1139MPa, which is less than the material yield strength of 1200MPa. Therefore, the static pressure condition meets the analysis requirements, and this size optimization scheme is the final optimal combination scheme. The battery pack topology / size integrated optimization design is completed. If the static pressure condition after verification does not meet the explosion-proof performance requirements, that is, the maximum stress of the battery pack structure exceeds the material yield strength of 1200MPa, then return to step 500, reselect the size optimization iteration, and determine a new size combination scheme until the optimal size combination scheme that meets the requirements is found.

[0091] like Figure 8 As shown, the present embodiment provides a design system for an explosion-proof power battery pack, including an acquisition module 10, a first creation module 20, a topology optimization analysis module 30, a second creation module 40, a size optimization analysis module 50, and a scheme design module 60. Among them, the acquisition module 10 is used to acquire the CAD geometric model of the battery pack; the first creation module 20 is used to establish a first finite element model of the battery pack according to the CAD geometric model; the topology optimization analysis module 30 is used to perform a topology optimization analysis on the first finite element model to obtain a first analysis result; the second creation module 40 is used to perform a first round of reconstruction on the CAD geometric model of the battery pack according to the first analysis result, and create a second finite element model according to the first round of reconstruction of the CAD geometric model; the size optimization analysis module 50 is used to perform a size optimization analysis on the second finite element model to obtain a second analysis result; the scheme design module 60 is used to receive the input operation performed by the user based on the second analysis result, and obtain the size design scheme of the components of the battery pack.

[0092] The design system of the explosion-proof power battery pack of this embodiment includes an acquisition module 10, a first creation module 20, a topology optimization analysis module 30, a second creation module 40, a size optimization analysis module 50 and a scheme design module 60. Specifically, the functions and effects of each module have been described in detail in the embodiment of the design method of the explosion-proof power battery pack, and this embodiment will not be repeated in detail here.

[0093] The design system of the explosion-proof power battery pack of this embodiment further includes a third creation module and a verification module;

[0094] The third creation module is used to perform a second round of reconstruction on the CAD geometric model reconstructed in the first round according to the second analysis results, and to create a third finite element model based on the CAD geometric model reconstructed in the second round; the verification module is used to perform static pressure working condition analysis and verification on the third finite element model to determine whether the maximum structural stress in the third finite element model is less than the material yield strength. If so, the optimization is completed; otherwise, the size optimization analysis of the second finite element model is re-performed.

[0095] Based on the size optimization analysis results, while meeting the requirements of component processing technology and battery pack structure assembly, the third creation module reconstructs the CAD geometric model reconstructed in the first round according to the second analysis results to form a new battery pack CAD geometric model (that is, the CAD geometric model reconstructed in the second round). The new sizes of all optimized design components undergo thickness changes on the outer surface of the battery pack structure, that is, the internal cavity structure of the optimized battery pack does not produce volume changes, which can ensure that the installation space of internal parts is not affected.

[0096] Based on the second round of reconstructed CAD geometric model of the reconstructed battery pack, the corresponding CAE finite element model (i.e., the third finite element model) is recreated for subsequent static pressure condition verification through the verification module.

[0097] The verification module performs static pressure condition analysis on the third finite element model to check whether the reconstructed structure meets the static pressure condition requirements. The static pressure analysis shows that the maximum stress of the battery pack is 1139MPa, which is less than the material yield strength of 1200MPa. Therefore, the static pressure condition meets the analysis requirements, and this size optimization scheme is the final optimal combination scheme. The battery pack topology / size integrated optimization design is completed. If the static pressure condition after verification does not meet the explosion-proof performance requirements, that is, the maximum stress of the battery pack structure exceeds the material yield strength of 1200MPa, then reselect the size optimization iteration and determine a new size combination scheme until the optimal size combination scheme that meets the requirements is found.

[0098] As a further improvement of this embodiment, the first creation module 20 includes a filling unit and a creation unit. The filling unit is used to fill the CAD geometric model of the battery pack with structural materials; the creation unit is used to establish a first finite element model of the battery pack according to the CAD geometric model filled with structural materials.

[0099] Specifically, the external structural material is filled into the CAD geometric model of the initial battery pack through the filling unit, and the outer contour of the original structure of the battery pack is enclosed to form the following Figure 6 The new geometric model shown in the figure has an unchanged internal cavity structure, and the entire battery pack is basically simplified into a cube from an external perspective. Then, the creation unit creates a CAE finite element model for the simplified cube, i.e., the outer contour envelope model, to obtain a first finite element model.

[0100] This embodiment provides a computer-readable storage medium, on which a program is stored, and the program can be executed by a processor to implement the above method. In view of the fact that the design method of the explosion-proof power battery pack has been described in detail in the above embodiment, this embodiment will not be repeated in detail here.

[0101] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0102] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A design method for an explosion-proof power battery pack, characterized in that: The explosion-proof power battery pack is applied to a mining vehicle, and the method comprises: Get the CAD geometric model of the battery pack; The original reinforcing rib structure around the outer surface of the CAD geometric model of the battery pack is deleted, and then the CAD geometric model of the battery pack is filled with structural material to a height up to the height of the original reinforcing rib structure, so that the battery pack is simplified into a cube, and a first finite element model of the battery pack is established according to the CAD geometric model after the structural material is filled; Performing a topology optimization analysis on the first finite element model through a density-stiffness interpolation model to obtain a first analysis result; determining the arrangement position, size, thickness and quantity of the reinforcing rib structure on the shell of the battery pack according to the first analysis result; the optimization design domain of the topology optimization analysis is the filling area of ​​the original reinforcing rib structure of the battery pack; Designing a reinforcing rib structure on the shell of the battery pack; performing a first round of reconstruction on the CAD geometric model of the battery pack according to the designed reinforcing rib structure, and creating a second finite element model according to the first round of reconstructed CAD geometric model; Performing a size optimization analysis on the second finite element model to obtain a second analysis result; wherein the components to be optimized in the second finite element model include: a top plate, a bottom plate, a left side plate, a right side plate, a top transverse rib, a top vertical rib, a side transverse rib, a side vertical rib, a bottom straight rib, a front cavity cover plate, a rear cavity cover plate, and a top cavity cover plate; reducing the structural mass by at least 20% is used as an optimization constraint of the size optimization analysis, and minimizing the structural stress is used as an optimization goal; A component size design plan for the battery pack is determined based on the second analysis result.

2. The method for designing an explosion-proof power battery pack according to claim 1, characterized in that: After obtaining the second analysis result, the method further includes: Performing a second round of reconstruction on the CAD geometric model reconstructed in the first round according to the second analysis result, and creating a third finite element model according to the CAD geometric model reconstructed in the second round; The third finite element model is subjected to static pressure condition analysis and verification to determine whether the maximum structural stress in the third finite element model is less than the material yield strength. If so, the optimization is completed; otherwise, the second finite element model is subjected to size optimization analysis again.

3. The method for designing an explosion-proof power battery pack according to claim 1, characterized in that: The performing size optimization analysis on the second finite element model to obtain a second analysis result includes: The second finite element model is subjected to size optimization analysis by means of a random sampling high-dimensional model representation method to obtain a second analysis result.

4. A design system for an explosion-proof power battery pack, characterized in that: The explosion-proof power battery pack is applied to mining vehicles, and the system comprises: An acquisition module is used to acquire the CAD geometric model of the battery pack; A first creation module includes a filling unit and a creation unit, wherein the filling unit is used to delete the original reinforcing rib structure around the outer surface of the CAD geometric model of the battery pack, and then fill the CAD geometric model of the battery pack with structural material, and the filling height is to the height of the original reinforcing rib structure, so that the battery pack is simplified into a cube; the creation unit is used to establish a first finite element model of the battery pack according to the CAD geometric model after the structural material is filled; A topology optimization analysis module, which performs a topology optimization analysis on the first finite element model through a density-stiffness interpolation model to obtain a first analysis result; and determines the arrangement position, size, thickness and quantity of the reinforcing rib structure on the shell of the battery pack according to the first analysis result; and the optimization design domain of the topology optimization analysis is the filling area of ​​the original reinforcing rib structure of the battery pack; A second creation module is used to design a reinforcing rib structure on the shell of the battery pack; perform a first round of reconstruction on the CAD geometric model of the battery pack according to the designed reinforcing rib structure, and create a second finite element model according to the first round of reconstructed CAD geometric model; A size optimization analysis module is used to perform size optimization analysis on the second finite element model to obtain a second analysis result; wherein the components to be optimized in the second finite element model include: a top plate, a bottom plate, a left side plate, a right side plate, a top transverse rib, a top vertical rib, a side transverse rib, a side vertical rib, a bottom straight rib, a front cavity cover plate, a rear cavity cover plate, and a top cavity cover plate; reducing the structural mass by at least 20% is used as an optimization constraint of the size optimization analysis module, and minimizing the structural stress is used as an optimization goal; The scheme design module is used to receive the user's input operation based on the second analysis result to obtain the component size design scheme of the battery pack.

5. The design system for explosion-proof power battery pack according to claim 4, characterized in that: The system also includes a third creation module and a verification module; The third creation module is used to perform a second round of reconstruction on the CAD geometric model reconstructed in the first round according to the second analysis result, and create a third finite element model according to the CAD geometric model reconstructed in the second round; The verification module is used to perform static pressure condition analysis and verification on the third finite element model to determine whether the maximum structural stress in the third finite element model is less than the material yield strength. If so, the optimization is completed; otherwise, the size optimization analysis of the second finite element model is re-performed.

6. A computer-readable storage medium, characterized in that: The medium stores a program, which can be executed by a processor to implement the method according to any one of claims 1 to 3.

Images