Scale Model Experiments for Safety Car Development

Scale model tests are conducted to demonstrate the utility of modeling in the study of automobile impact problems. Specifically, the interaction of the bumper and energy-absorbing frame of an Experimental Safety Vehicle (ESV) during impact against a rigid pole at 50 mph is investigated with one-eighth scale models of the ESV. The models duplicate the mass and energy-absorbing characteristics of the ESV and the materials and important construction detail of full-scale bumpers. Aluminum alloy and high-strength steel bumpers with equivalent full-scale weights from 48-146 lb are tested. Acceleration to 50 mph is provided by a pneumatic launcher; impact is recorded by high-speed cameras.

Accuracy of the modeling technique is demonstrated by favorable comparison with full-scale experiments conducted by Ford Motor Co. The more extensive tests possible with the scale models show that the lightest successful bumpers are made of 7075-T6 aluminum and would weigh less than 64 lb in full scale.