| In recent years,electric vehicles have developed rapidly because of their advantages of zero pollution,low noise,efficient and convenient,and have been favored by the majority of consumers.As the only source of power of the electric vehicle,the power battery pack plays a key role in the performance of the electric vehicle.However,the endurance capacity of electric vehicles is quite different from traditional fuel vehicle,and the introduction of power battery pack also greatly increases the quality of electric whole vehicle.Same as the fuel vehicles,power consumption and weight of electric vehicles are closely related,the weight vehicle weight is lighter,its endurance is higher,thus reducing the number of replacement of power battery and saving the cost of use effectively.Therefore,it is of great significance to the lightweight design of power battery pack.This article takes the power battery pack of a pure electric vehicle as the research object,uses the finite element method to optimize different structural parts in the battery pack,and discusses the change of the overall static and dynamic performance of the battery pack after the structural parts are optimized and the impact of optimization of structural parts on vehicle safety performance.Its main research content is as follows:Firstly,according to the analysis needs,the use of CATIA for the pure electric vehicle power battery pack structure to simplify.At the same time,based on the finite element modeling principle of the vehicle,the finite element model of the battery pack is established by using the HyperMesh.Secondly,the use of MSC.Nastran solver for battery package static analysis and modal analysis.Through analysis,it can be seen that the stress and strain of the structural parts of battery pack are within the safe range under various working conditions,and the stress is much lower than the yield strength of structural material,which means that the structural components of the battery pack are too thick and conservative.In addition,the first-order modal frequency of the battery pack is very close to the excitation frequency of the electric vehicle,and it is easy to generate a large-scale vibration.Therefore,it is necessary to further optimize the structure of the battery pack in order to achieve a reduction in the weight and dynamic performance of the battery pack.Thirdly,according to the analysis result of the static and dynamic performance of the battery pack,Optistruct is used to optimize the power battery pack.By means of material replacement as well as size and topology optimization of the battery pack,the weight reduction and improvement of the overall structural performance of the battery pack are achieved.Through optimization,the optimized power battery pack still has good static performance and its dynamic performance is significantly improved when the overall quality is reduced by 6.3%.From this,it can be inferred that this optimization scheme has certain feasibility.Finally,the collision model of an electric vehicle was established,and LS-Dyna solver was used to perform a collision simulation analysis of the model in accordance with safety crash regulations in order to verify the safety performance of the battery pack after optimization.The verification results show that the optimized structure of battery pack meets the safety performance requirements of the electric vehicle battery,and its inspection indicators are within the normal range.At the same time,it further proves the feasibility of this optimization design. |
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