Stress Prediction and Optimization of Power Battery Pack under Random Vibration

Aiming at the structural strength of the power battery pack of new energy vehicles under random vibration conditions, a finite element simulation method is used for analysis and optimization. Based on the geometric data of the power battery pack, a detailed finite element model is constructed, constraints are applied to the lug mounting points of the battery pack, and three-directional power spectrum loads are applied to simulate the complex vibration environment during vehicle driving. The simulation results show that the stress level of the module bracket and the upper box cover exceeds the material yield strength, and there is a problem of insufficient structural strength. The key components are optimized by increasing the thickness and adjusting the cross-section height through the optimization scheme. After optimization, the module bracket stress is reduced from 267.249 MPa to 201.648 MPa, with a decrease of $24.55 \%$; the upper box cover stress is reduced from $\mathbf{1 5 7. 0 5 4} \mathbf{~ M P a}$ to $\mathbf{6 0. 2 4 2}$ MPa, with a decrease of $61.65 \%$, which meets the design requirements. The optimization results show that the stress prediction under random vibration can be used in the conceptual design stage for the structural design of the power battery pack, which provides practical support for the design and optimization of the battery pack.