A Study on the Characteristics of Occupant Injury Severity at Different Positions of Seat Adjustments

Automobile seats provide comfort to passengers and play a crucial role of protecting occupants from a car accident. Seats also have many adjustment mechanism systems to provide various sized occupants with comfort and convenience. However, occupants who sit in out-of-position could be more severely injured from an accident. To enhance occupant's safety, precrash seat system is introduced and many different approaches are made to improve performance. Precrash seat system is an active safety system to give occupants warnings or to control the adjustment devices to move to a safer position before the event of car accident. In this study, occupant injury severities at different positions of seat adjustment systems are evaluated to find out safer locations of the seat in advance of studying precrash seat system. Finite element analysis (FEA) of the frontal collision at different seat adjusted positions is conducted using LS-DYNA FEA code and the occupant injury probabilities are evaluated based on the NCAP criteria. It is found that injury probabilities are lower at the midway of the fore-aft travel of the seat and at a less reclined angle of backrest. In addition, the deflated position of pneumatic thigh support provides lower probability of injuries.