Several phenomena in structural impact and structural crashworthiness

This article discusses the dynamic plastic instability of various basic structural members, subjected to large axial impact loads, which is relevant to the fields of structural impact and structural crashworthiness. In particular, studies on the dynamic axial response of idealised elastic–plastic models, rods, cylindrical shells and square tubes, is discussed in some detail. The analyses for some of the rods, shells and tubes retain the simultaneous influence of elastic and plastic stress waves (axial inertia) and the structural response (lateral inertia). The predictions reveal the profound influence of stress wave propagation phenomena which explain the characteristics of many of the experimental results obtained in laboratories over the years. These more complete analyses are vital for the higher velocity impact scenarios encountered increasingly in designs and for comparing properly the relative merits of different ductile materials in potential energy absorbing systems.