Crumple Zones in Automobile Vehicles

Crumple Zones in Automobile Vehicles


INTRODUCTION  :

The optimization of automotive vehicles structure in order to improve the passenger safety ahs long been a priority in vehicle design. Vehicle crash is dynamic phenomenon featuring a complex interaction between structural and inertial behavior. In crash events, automotive structures are subjected to loading of high intensities, which includes transient deformations ranging from small deformation and small strain to large plastic permanent deformation with large strain.

In typical collision, it is the outer envelope, which experiences the impact and undergoes deformation locally in the impact region. The occupants only later experience the impact. Thus one can define the encounter of the outer envelope of an automotive vehicle with an external object at the first collision and the subsequent collision undergone by the occupants within the passenger compartments as the second collision. Obviously the severity of the second collision involving occupant motion is of the primary concern in occupant protection from injuries and collisions , in general severity of second collision is strongly related to first collision.

Therefore it has been desirable situation to design an automotive vehicle in such a way that during collision some portion of structure will be designed as energy absorbing zones to absorb the impact kinetic energy in predictable manner, while the passenger compartment retains it rigidity, as much as possible to reduce intrusion into areas occupied by vehicle occupant. These energy-absorbing zones are called crumple zones. Crumple zone analysis focuses on the prediction of large deformation of automotive structure subjected to collision.