On crashworthiness design of hybrid metal–composite battery-pack enclosure structure

Considering the crashworthiness and lightweight of the battery-pack enclosure structure (BPE), this article demonstrates multi-objective optimization design of BPE subjected to extrusion conditions by using a validated numerical model and an analytical approach. BPE is made with a unique combination of three materials: a high-strength steel (HSS) surrounding enclosure, an aluminum below enclosure, and a carbon fiber-reinforced polymer (CFRP) upper enclosure. First, the constitutive model of BPE material was determined based on the results obtained in material testing, meanwhile, the structural extrusion analysis of the initial BPE was performed and validated by the published experimental data. Second, a contribution analysis method based on modified TOPSIS (MTOPSIS) is adopted to screen the design parameters of the optimal structure. Based on this, the mass of the BPE and the maximum extrusion deformation of the BPE are employed as objectives to establish an optimization mathematical model. Furthermore, improved multi-objective particle swarm optimization (IMOPSO) has been exerted as the optimization algorithm to conduct optimization design, the results show the optimization model has a better optimization level and fitting ability. Finally, the performance comparison results before and after model optimization show the crashworthiness performance can be improved significantly, while the lightweight performance of BPE is ensured.