Comparison Testing of Bumper Isolators 1999-01-0096
The severity of low-speed front and rear impacts is commonly assessed through testing of the actual or exemplar vehicles or by comparison with available barrier test data. While tests conducted on actual or exemplar vehicles are most accurate, barrier testing also provides dynamic properties of the bumper isolators in a controlled manner.
The goal of this paper was to determine if barrier testing of a single isolator can be used to assess the behavior of an intact bumper on an actual vehicle. Replacement bumper isolators for 15 vehicles were individually mounted to a moving barrier and subjected to low-speed impacts with a fixed barrier to correlate their dynamic compression with impact severity. The single isolator results were compared with actual vehicle barrier test results. A total of 1624 tests were conducted.
A 2nd order linear spring-mass-damper model was used to predict impact severity characteristics of the actual vehicle from the single isolator data.
It is concluded that single isolator testing can be used to predict the speed change and change in kinetic energy for an actual vehicle in most cases, while the restitution can not be accurately predicted.