Design and reinforcement of vehicle side structure for vehicle crashworthiness and occupant protection under MDB side impact

Vehicle side impact accidents have high fatality rates due to limited deformation buffer and insufficient energy absorption of side structures. Simply enhancing structural stiffness and energy absorption characteristics may lead to increased occupant injury risk under side impact. To simultaneously improve side crashworthiness and occupant protection, this study proposes an origami-inspired honeycomb reinforced side structure and conducts systematic research. First, a full-scale finite element model of mobile deformable barrier (MDB) side impact has been established and verified with test data. Although besides impact simulation results reveal qualified structural crashworthiness, the occupant injury especially the head injury criterion (HIC15) is too high due to excessive intrusion of the vehicle body side structure. To address this problem, an origami-inspired honeycomb structure has been designed and embedded into the B-pillar and threshold beam. Then a meta-model based multi-objective optimization has been performed to improve the crashworthiness and occupant protection of the vehicle. Finally, crashworthiness comparison results demonstrate that the optimized reinforced structure significantly improved energy absorption and intrusion resistance, reducing occupant head and abdomen injuries.