An overall improvement in the crash characteristics of vehicle body, occupant restraint devices (seat belt and air bag etc.) and energy absorption characteristics of the secondary impact objects (steering and instrument panels etc.) is essential for minimizing injuries to occupants when a vehicle gets involved in an accident. It is needless to say that striking proper balance among these is the main crux in designing. For this, it is necessary to analyze the behavior of occupants at the time of accident and the state of injuries they sustain so that the contribution of each factor to the injuries can be pinpointed.

This paper discusses the investigations carried out by the authors on the effects of crash characteristics of the vehicle body, position of the windshield glass and instrument panel and the rigidity of instrument panel and cross beam etc, on the injury values of the dummy, after analyzing the behavior of unrestrained dummy in the passenger seat during frontal collision at 30 MPH and 15 MPH by carrying out simulation with MVMA-2D program and by sled test.

This study enabled the authors to gain some significant information on the effects of internal fittings on the injury values of the dummy. Sled test carried out with vehicle modified on the basis of these data confirmed the validity of the findings.