Static-Dynamic Coupled Lightweight Design and Multi-Objective Optimization Method for Aluminum Alloy Battery Enclosures of Electric Vehicles

The collaborative optimization of structural safety and lightweight design of battery enclosures is key to improving the driving safety and energy efficiency of electric vehicles. Aiming at the limitations of single-condition optimization and the lack of multi-physical field coupling analysis in the traditional design method, a static-dynamic coupled lightweight design and multi-objective optimization method for aluminum alloy battery enclosures of electric vehicles is proposed. Based on the modal test-validated high-fidelity finite element model of the original aluminum alloy battery enclosure, conduct modal and extrusion simulation analysis to clarify performance design indicators.Design of a new aluminum alloy battery enclosure and construction of a high-precision multi-physics simulation system covering modal, static strength, dynamic impact and extrusion conditions.Combining morphological optimization and RBF surrogate model, a multi-objective size optimization is realized based on the PSO-GA hybrid optimization algorithm. After optimization, the new enclosure mass is reduced by 11.6%, while maintaining the benchmark shock resistance performance, the first-order modal frequency is increased by 23.86%, and the static stiffness indicators are improved by 18.37%, 6.36%, and 25.26% respectively.The dynamic extrusion resistance performance is improved by 21.11% and 14.88% respectively. Compared with the original enclosure, mass is reduced by 17.7% and extrusion resistance performance is improved by 25.18% and 12.55% respectively. The complex nonlinear multivariate optimization problem under multi-physical field coupling of aluminum alloy structural design is solved, and the collaborative improvement of safety performance and energy consumption is realized.