Lightweight Design of an Automotive Battery-Pack Enclosure via Advanced High-Strength Steels and Size Optimization

The battery packs are crucial components of electric vehicles and may severely affect the continue voyage course and vehicle safety. Therefore, design optimization of the battery-pack enclosure (BPE) is critical for enhanced mechanical and crashwrothiness performances. In this study, a lightweight design of an automotive BPE under the loading conditions is presented based on the advanced high-strength steels (AHSSs) and size optimization. A numerical analysis procedure is also introduced for the lightweight design. First of all, a nonlinear finite element (FE) BPE model was established and validated through the modal test. Secondly, the random vibration simulation was performed based on the sensitivity analysis to initially determine the AHSSs and thickness for the components of the BPE. Next, the material and thickness were determined by the fixed-frequency vibration analysis. Moreover, the mechanical shock and fatigue life were analyzed numerically. Finally, the crashworthiness of the optimized BPE model was verified by crash and crush simulations. The results show that the optimized BPE structure has a 10.41 % lightweight gain, while assuring enhanced dynamic performances. The introduced numerical procedure could be used to quickly determine the material and thickness of each component of BPE. The design optimization process was found beneficial to reduce the number of physical tests and product development cost and shorten product development cycles.