‘Egg-box’ panel for commercial vehicle front – compressive loading tests

Abstract

The numbers of serious accidents and fatalities from accidents between commercial vehicles and vulnerable road users (VRUs) are still high and show no sign of declining. For pedestrians, this is traumatic due to high incompatibility of vehicle fronts. Hence, decisions have been made to implement countermeasures that have the potential for casualty reduction. This paper proposes an ‘egg-box’ energy-absorbing panel to be incorporated in a commercial vehicle's cab front and sides. As a consequence it is expected to reduce the load between vehicle and pedestrians, while at the same time eliminating the risk of serious injuries and fatalities. The egg-box panel herein has been compressed under quasi-static conditions in order to study the collapse mechanism of the structure and quantify the corresponding load regimes for various stages of collapse. An attempt has been made to understand the structure's energy-absorption capability from the resulting load-deflection curves. Also, a simple assessment of the structure's crashworthiness is discussed and comparison made to existing energy absorbers. The maximum load that a 30 mm high panel structure can withstand is approximately 18 kN. Unlike in a concertina tube where a sudden drop in load is observed after the formation of the first plastic hinge, there is no drastic fall in this load after the collapse has started. A steady load is observed with the progressing deformation. With the height reduced to 20 mm, the maximum load capacity increases by 20% approximately along with increase in the stiffness.

Keywords:

• crashworthiness
• aggressivity
• quasi-static
• frusta
• plastic hinge
• densification point

Acknowledgements

The authors are grateful to CELLBOND Ltd., Huntingdon (UK) for their collaboration with BAARG at University of Bolton and for supplying the specimens.