Abstract
There is a growing recognition by the auto makers of the benefits of aluminum for vehicle structures. While there is now no doubt that the structural demands of vehicles can be met with aluminum, it is less well appreciated that such structures can also be designed to provide a high level of crashworthiness.
This paper summarizes the basic work that has been carried out to demonstrate and quantify the behavior and energy absorption of aluminum vehicle structures under impact collapse conditions. Aluminum, like steel, collapses under high load conditions by folding and the resulting work of deformation absorbs the vehicle’s kinetic energy. It follows that most of the general rules for designing crashworthy structures in steel, in terms of ensuring progressive collapse, avoiding premature bending failures, and transferring load as the collapse event proceeds, apply equally well to aluminum structures. There are, however, differences from steel due to the greater thickness of aluminum material used. This increases resistance to local buckling, and results in larger volumes of the material becoming involved in the energy absorbing collapse events.
There are other material characteristics that have a bearing on developing crashworthy aluminum structures, and the paper covers the more significant material and related design guidelines that should be followed in the development of the main energy absorbing structural members in vehicle structures. Finally, reference is made to results from NHTSA’s NCAP program for appraising the crashworthiness of new vehicles. These have demonstrated in a very practical way the excellent crashworthiness of vehicles with well designed aluminum structures.
