Impact-With-Rebound: An Advanced Tool for Laboratory Crash Simulation 700406

This paper shows that the shock motion experienced by the passenger compartment during inelastic impact of an automobile into a barrier may be simulated in the laboratory by elastic impact between a test carriage and a reaction mass. Mathematical derivations show that impact-with-rebound is equivalent to the “impulse” (test specimen accelerated backward from rest) and impact-without-rebound simulation methods.Velocity, displacement, and dimension formulae are derived for all three test methods and are compared in terms of system performance and configuration. It is shown that for the same performance, the rebounding simulator requires less impact velocity (and therefore less total energy), less shock pulse programmer displacement, and shorter track length than the other systems.One type of rebounding shock pulse programmer is discussed in detail. It is explained how the force-versus-deflection characteristic can be controlled by adjusting internal gas pressures.A typical crash simulation system using the impact-with-rebound technique is briefly discussed.