Research On Optimal Design Of Battery Pack Structure For Pure Electric Vehicles

As the "heart" of a pure electric vehicle,the power battery pack is the main power source of the vehicle,which plays a decisive role in the performance of the vehicle,and the performance of the battery pack is affected by parameters such as the number of cells,energy density,and cabinet.Compared with traditional fuel vehicles,there is still a certain gap in the cruising range of pure electric vehicles,and the safety of battery packs is also a concern for users.Therefore,the research on the optimization design of the power battery pack structure of pure electric vehicles is of great significance.This paper designs and optimizes a new power battery pack based on the design requirements of a pure electric vehicle chassis for the battery pack.Use finite element technology to do corresponding simulation analysis of the battery pack,and combine topology optimization,shape and size optimization methods to optimize the battery pack structure,and study the development plan and process of finite element simulation-driven product design.The research content is as follows:(1)First,according to the design requirements provided by the vehicle model,combined with the research status,the basic parameters of the battery pack structure are preliminarily designed,including the weight,capacity,module and battery cell,box body and load beam and other parts of the size,materials and connection methods;Use Catia software to draw the parametric models of battery pack parts,and complete the assembly according to the constraint relationship.(2)Then use Hyper Mesh software to perform geometric cleaning,meshing,cell quality inspection,material attribute assignment,connection and contact settings on the 3D model of the battery pack,establish a simulation model,and use Opti Struct to simulate and calculate the battery pack’s braking,bumping and turning Static performance under extreme conditions,modal analysis calculates the various modes and modes of the battery pack structure,analyzes and evaluates its dynamic performance,and provides reference data for structural optimization.(3)According to the simulation and evaluation results,the topological optimization design of the load-bearing beam at the bottom of the battery pack is carried out,the distribution of the load-bearing beam axis is calculated,and the size is optimized to calculate the cross-sectional size of the beam;the rigidity of the box cover is insufficient,and the shape optimization adds stiffeners;Optimize the size of thin-walled parts,including the thickness of the lower cover,the thickness of the upper cover,and the thickness of the module fixing bracket as optimization variables to optimize the optimal thickness size.(4)Finally,complete the geometric reconstruction of the battery pack according to the optimized calculation results,and then perform simulation analysis of the corresponding working conditions to compare the analysis results before and after the optimization;on the premise that the battery pack capacity remains unchanged,the battery pack mass is reduced by 41.7kg(about 8.44%)),the maximum displacement under quasi-static conditions is reduced from 8.5861 mm to 3.5684 mm to improve the stress concentration of the load-bearing beam,and the first-order natural frequency is increased from 24.04 Hz to 40.71 Hz,avoiding the resonance frequency band.