Search Results

Much of the design and development of the modern automobile is dedicated to protecting occupants or reducing vehicle damage during and after a crash. Although the primary function of the vehicle body structure in this respect is to dissipate the kinetic energy of the vehicle, effective protection depends upon careful management of this energy in order to achieve the optimum collapse mechanism. For conventional metal components, the art of creating such “crashworthy” performance is now well understood. However, more and more vehicles are turning to polymer-based composite materials in their structures and these exhibit a totally different type of behaviour in the way that they dissipate energy to the metals which they replace. This paper reviews the fracture mechanisms of these materials, in relation to different impact speeds, as they affect the vehicle designer.

Side impact crashworthiness presents a complex problem due to the dynamic interaction between the occupant and the intruding vehicle side structure. As there is a direct impact between the occupant, and the door and B-post trim, small variations in the vehicle structural behaviour can have a significant effect on the dummy response and injury levels. Significant variability in dummy response between crash tests causes problems when evaluating the vehicle side structure and development of side impact restraint systems. A programme of research tests has been conducted at the Motor Industry Research Association (MIRA) using the MIRA - Side Impact System (M-SIS) technique to evaluate the dynamic response of side impact dummies in actual side impact environments. With the implementation of the European side impact legislation in 1998 the effects of variations in dummy location and velocity profile need to be understood.