The objective in this study was to determine how different car interior geometries and crash pulses would affect specific occupant responses during a head-on car crash. To study a 'worst-case scenario', the occupant was unbelted and there was no airbag. An experimentally validated MADYMO-PAMCRASH model was used to study the effect of the following 'input parameters' on the risk of knee injury and the kinetic energy of the upper body: instrument panel (IP)stiffness, seat height, knee-instrument panel distance, knee flexion angle, toe-pan angle, instrument panel angle, and crash pulse delta V (velocity change). It was found that the risk of knee injury was most sensitive to the lP stiffness, crash pulse delta V, and the precrash distance between the knee and lP. The kinetic energy of the upper body, however, was sensitive to the seat height and initial knee flexion angle, as well as the delta V and initial distance between the knee and lP. Regression models were developed which predicted the MADYMO-PAMCRASH femur loads, knee contact areas, and upper body kinetic energy as a function of the input parameters described. In conclusion, the study identifies key vehicle design and crashworthiness parameters which affect the risk of knee injury and the kinetic energy of the upper body.
Abstract