Simulation research on bottom crash test of power battery pack based on a specific vehicle

DAI Jiangliang; MENG Xiangyu; CHEN Qi

doi:10.16579/j.issn.1001.9669.2026.07.021

Abstract：[Objective]Significant stress and deformation characteristics are exhibited by power batteries during charging and discharging,and higher requirements are imposed on battery management and pack design accordingly.To accurately evaluate the structural strength state of power battery packs and the safety and health state of single cells in bottom impact tests,the critical intrusion amount that triggers fire and explosion of single cells under specific scenarios or working conditions shall be clearly defined.Accurate predictions of the structural strength state of power battery packs and the safety state of single cells in bottom impact tests were performed by means of simulation methods.Based on the numerical test model,the dynamic response characteristics and energy distribution laws during the impact process were thoroughly analyzed.[Methods]Firstly,a refined explicit dynamic finite element model for the bottom crash test of a power battery pack was established using Abaqus software.Secondly,the displacement,equivalent plastic strain,and energy distribution of the structures were calculated and evaluated.[Results]Simulation results show that the deformation shapes,intrusion amounts,and strength statuses of the impacted components are highly consistent with the test data.The simulation accuracies for the intrusion amounts of the bottom guard plate,liquid-cooled plate,and battery cell housing are 94.36％,98.80％,and 96.78％,respectively.The maximum impact force of the ball head reaches 27 299 N.Concurrently,80.96％of the total impact energy is converted into the strain energy of the main impacted components,and their energy absorption proportions correlate positively with the corresponding intrusion depths.These findings provide a valuable theoretical reference for the underbody safety protection design of battery packs.