Novel Steel Tubular Side Sill Reinforcement Design and Validation for Enhanced Crash Performance in EVs

Increased use of Electrical vehicles (EVs) brings in unique structural design challenges particularly in Side Impact scenarios when the battery pack is near the sill region therefore elevating the possibility of Electrical Module penetration and triggering thermal runway event resulting from the crash. Thus, Electric Vehicles present unique structural design challenges. This study intends to evaluate a novel tubular structure design for side sill reinforcement and its performance benefits over a traditional aluminum side sill reinforcement currently commonly utilized for battery protection in EV vehicles body components. The proposed Steel side sill design mainly focuses on structural rigidity and improved load transfer during side pole impact crash cases and address manufacturing complexity and cost reduction opportunity.  Multiple iterations for Steel side sill reinforcement design were carried out using finite element analysis with software like LSDYNA Hyper works to propose optimal design layout for the tubular structure targeting maximum load transfer and energy absorption. The study was conducted in two stages 1) CAE: Full vehicle and Component Simulation 2) Physical:  Component Test Validation. Initial design parameters derived from using full vehicle and component CAE, and then the design was validated using mechanical testing. The findings show that the proposed Steel tubular side sill reinforcement structure has similar performance characteristics compared to base Al design and indicate possibility of reduced manufacturing complexity, cost and mass saving opportunities. The results of this analysis confirmed that the proposed Novel side sill reinforcement applied to EV specific Body in White (BIW) helps to design safer vehicles and effectively meet both regulatory requirements and consumer expectations.