Modularized Design And Simulation Analysis Of PEV Power Chassis Structure With Battery Pack

The special power chassis modularization is a key technical problem for the development of pure electric passenger vehicles that can significantly alleviate energy and environmental pressure.This paper adopts the combination of topology optimization and pedigree cluster analysis to carry out modular design of pure electric passenger vehicles.The research proposes a three-stage new power chassis module configuration with the length of the chassis module and the intermediate module before and after generalization,and optimizes the wall thickness of the main bearing member of the intermediate module through the collision safety simulation test.The compact design method under natural air cooling conditions has been explored,mainly solving the following key technical problems:(1)Decompose the function of the pure electric vehicle chassis according to the principle of independence and establish the correlation matrix R.The pedigree clustering method can be used to divide the chassis into three-stage new configuration with the length of the chassis module and the intermediate module before and after the generalization;For example,a compact car is used to establish a chassis topology optimization model under normal collision and rear-end conditions.The three-stage power chassis model is established according to the actual machining assembly function requirements and reference to the relevant models.(2)According to GB/T 31498-2015,the frontal crash simulation experiment is carried out on the modular chassis.When the thickness of the middle longitudinal beam is 4 mm,the collision acceleration is less than 50 g,the longitudinal intrusion of the front beam of the intermediate module is 5.40 mm,and the longitudinal compression of the longitudinal beam is the largest.5.72 mm.Based on the collision safety,the longitudinal beam of the intermediate module is lightly optimized.The thickness of the longitudinal beam is reduced to 2,3,and 2.5 mm,and the longitudinal compression of the longitudinal beam of the intermediate module is 24.52,6.94,and 9.38 mm,respectively.The longitudinal intrusion of the front beam is 10.02,5.80,5.95 mm.When the safety requirements are met,the wall thickness can be reduced from 4mm to 2.5mm,and the main longitudinal beam of the intermediate module is reduced by 37.5%.(3)A battery box configuration of a battery misaligned array composite concave and convex box wall is proposed.Under natural wind cooling conditions,the thermal simulation orthogonal test shows that the structural parameters affecting the heat dissipation effect are mainly the inlet diameter,the column spacing and the margin.The characteristic dimension design of the battery box layout structure is obtained by fitting the analog tuning function.The relative error between the verified design calculation result and the thermal simulation result is less than 5%,which can be used as a reference for the design of the battery box structure,combined with the local margin size and the box body.The optimization of the rounded corners finally achieves a compact battery box structure with a line spacing of 25 mm,a column moment of 30 mm and a minimum margin of 15 mm,which can achieve the goal of a battery operating temperature of 0 to 40°C and a temperature difference between modules of 5°C or less.