How to conduct a crash test

During recent years the development of new vehicles has to deal with continuously emerging requirements to ensure pedestrian protection as well as improve vehicle damageability and repairability.

In low-speed vehicle crashes, vehicles must withstand the crash with minimum damage so that the repair cost incurred remain as low as possible. Vehicle bumper need to fulfill a number of functions such as pedestrian protection and better aerodynamic design. In addition to these two major functions, another important function of vehicle bumper system is to absorb most of the impact energy and protect the remaining structure of the vehicle from undergoing plastic deformation.

The energy absorption capability of the bumper system during a crash is evaluated by the load-displacement response. The area under the corresponding load-displacement curve is a measure of the energy absorbed (Fig. 1). In order to prevent the vehicle body structure being damaged by the impact, the maximum energy transmitted to the BIW must be limited, which means the area under the force-displacement curve should be maximized. Therefore, the ideal bumper system has a force-displacement curve similar to a step function. The force jumps to the maximum allowable value and remains there throughout the crash.