The Effect of Structural Stiffness on Occupant Response for a -Gx Acceleration Impact

This study relates the structural stiffness and kinetic energy of impact to the dynamic response of a belted vehicle occupant. Acceleration time histories of impact for structures with different stiffnesses were obtained by performing a finite element analysis using the LS-DYNA3D finite element program and a model representing a structural member made of AISI 4340 steel. For the human body dynamics analysis, the Articulated Total Body (ATB) computer program was used to perform six simulations of a 50 percentile male restrained by a 3-point seatbelt system for a co-linear -Gx impact.

The results of the study indicate: (1) an increase in the maximum acceleration and a decrease in the duration of the impact with the increase in structural stiffness (2) an increase in the maximum acceleration and duration of impact with the increase in kinetic energy of impact (3) an increase in load on the vehicle occupant's head and neck with an increase in acceleration and a decrease in duration of impact.