A Method for Determining the Impact Force in Crash Testing


A method for measuring the impact force in crash testing is developed. In this method, a mass is made to collide with the object being tested and the instantaneous value of the impact force is measured as the inertial force acting on the mass. To realize linear motion with a sufficiently small friction acting on the mass, a pneumatic linear bearing is used, and the velocity and acceleration of the mass, the moving part of the bearing, are measured using an optical interferometer. The relative combined standard uncertainty in determining the impact force in a three point bending test is estimated to be 0.5~10-2 (0.5 %) of the maximum value of the impact force.