The Application of Elastomeric Buckling Columns in an Energy Management Bumper System

In an Energy Management Bumper System (EMBS) maximum energy-absorption efficiency is achieved with a “square wave” load/deflection response. The laboratory and barrier impact tests conducted in this study show that elastomeric columns provide essentially square wave response during the buckling stage of column deflection. Of the materials tested, high diene-low Mooney EPDM (terpolymer of ethylene, propylene and a diene) materials fabricated into hollow cube absorber units exhibited square wave efficiencies of 85-90% and were found to be the most suitable elastomers for an EMBS application.

The efficient use of the elastomeric absorbers in an EMBS was accomplished by placing a metal face plate in front of the units to distribute the impact force across the face of the vehicle. This concept was applied to an engineering design for a 3000 lb. vehicle EMBS that would handle impacts at 5 mph in compliance with Federal Motor Vehicle Safety Standard No. 215.