Experimental Evaluation of Rear Under-Run Protection Device

The heavy commercial vehicles are equipped with under-run protection devices (UPD) to enhance safety of occupants in small vehicles in the event of under-run. These UPD are popularly classified as RUPD (rear under-run protection devices), SUPD (side under-run protection devices), FUPD (front under-run protection devices). These devices primarily work to improve safety of smaller vehicles by changing its interaction with heavy vehicles thereby resulting in change in small vehicle structural engagement for energy absorption. Without UPD, smaller vehicle passenger compartment is likely to interact with stiff commercial vehicle chassis frame structures. However with UPD, the smaller vehicle front-end structure gets involved in the crash which helps in controlled energy absorption and safe-guards the passenger compartment.

At present, regulatory criteria have been defined for the minimum static strength, stiffness requirements at component level for these UPD besides dimensional requirements for their installations on the commercial vehicles. However, it was of interest to study the effectiveness of these devices for enhanced occupant safety in real-world accidents and significance of the regulatory structural requirements. The paper describes the assessments of dynamic crash tests of a passenger car and a stationary heavy truck fitted with and without RUPD. The assessment includes structural interactions and interactive forces between them.