The Effects of Small Seat Swiveling Angles on Occupant Responses during a Frontal Impact 2020-01-0571

In highly automated vehicles (HAVs), new seat configurations may be desirable to allow occupants to perform new activities. One of the current HAV concepts is the swiveled seat layout, which might facilitate communication between occupants. The main objective of this study was to investigate the effects of seat swiveling angles on occupant kinematics and injury risk predicted by a Human Body Model (HBM) during a frontal impact. A detailed 50th percentile male HBM (GHBMC M50-O) was subjected to two frontal crash pulses in a sled setup. The model was positioned on a semi-rigid seat and restrained using a pre-inflated airbag and a three-point seatbelt. Simulations included four seat swiveling angles (0, -10, -20, and -30 degrees), three occupant positions (Sedan driver, large VAN driver or Laptop user), two airbag initial locations (nominal or matching the head Y location), and the inclusion of lateral supports on the seat pan. The effects of the seat swiveling angle were similar for all occupant positions. With the airbag in the nominal location, higher seat swiveling angles led to a higher head lateral displacement and a higher risk of head injury, especially for the BrIC criterion. The Sedan driver position had higher BrIC and a larger head lateral excursion than the other two positions. This could be mitigated by aligning the airbag location with the head. Pelvic fractures were also predicted for the configurations with the highest swiveling angles. These fractures were limited by the use of seat pan lateral supports. Overall, the model responses were sensitive to both seating configurations and occupant postures, and the results suggest that swiveled seating may increase the injury risk, especially for the head and pelvis. However, simple countermeasures, such as adapted airbag location or adding lateral seat pan supports, seemed possible to mitigate the risk.