Integrated Structural and Impact Optimization for a Lightweight 6-Wheel Electric Truck Chassis.

This study presents a comprehensive optimization strategy for the chassis design of a 6-wheel electric vehicle (EV) truck, focusing on weight reduction while maintaining structural integrity and crash safety. Unlike previous studies that prioritize either weight minimization or static performance, this work integrates crashworthiness constraints to ensure occupant safety under dynamic impact scenarios. The proposed method optimizes the dimensions and positions of side rails and cross members, addressing critical constraints, such as bending stiffness, safety factor, and frontal crash deformation. Three optimization approaches are evaluated: Case I, which optimizes only side rails, achieves a minor 8 kg reduction; Case II, which extends optimization to cross members, leads to a 27.43% mass reduction but compromises crash safety. The proposed method strikes a balance, reducing chassis weight by 13.08% to 206 kg while meeting all structural and crash safety requirements. This study underscores the importance of a holistic optimization framework that simultaneously enhances weight efficiency and crashworthiness, contributing to the advancement of lightweight, safe EV truck designs.