The effect of a braking maneuver on the occupant’s kinematics of a highly reclined seating position in a frontal crash

Abstract

Objective This study aims to make the comparison of the kinematics and possible injury values of the occupant in the highly reclined seating position in two cases: the first case is without the braking maneuver prior to the frontal crash, and the second case is considering the braking maneuver prior to the impact. Methods This study used the MADYMO human body model 50th percentile mid-size male seated on the front passenger seat model with the seatback reclined rearward 53° (fully reclined seatback) to simulate the occupant biomechanics and behavior during a frontal collision. To achieve the study aim, two simulation models were created. The first model is called the non-precrash model (VaAM-O). It was set to simulate the occupant kinematics in the fully reclined initial seating posture in the 200 ms of a crash without the braking maneuver before the crash. The second model, called the precrash model (VaAM-I), identified the occupant’s initial position after the car model performed a 1s deceleration of a braking maneuver. VaAM-I has then also simulated the occupant kinematics in 200 ms of a crash. Results This study showed a significant difference in the occupant’s posture at the beginning of the crash phase in the two cases. The upper torso of VaAM-I rotated up and moved forward earlier than VaAM-O prior to the crash phase due to the influence of the braking maneuver, and at the 50 ms, when the airbag deployed completely, the head had no contact with the airbag, and the head in VaAM-I forwarded to the airbag closer than VaAM-O about 24% of the distance to the airbag. Conclusions This study supplements the value data for the study of the out-of-position OOP of the occupant in the frontal crash. The contact force and position contact between the head and the airbag could attract the audience’s attention. On the other hand, a comparison of the seatbelt force and the seatbelt contacts the body between the conventional seatbelt as in this study, and the seat-integrated seatbelt system in the case wherein the occupant seats on the front seat with a highly reclined seatback should be performed.