Development of Multi Aluminium Foam-filled Crash Box Systems to Improve Crashworthiness Performance of Road Service Vehicle

Honeycomb crash absorbers are known as mechanical energy-absorbing systems in both automotive and aerospace industries. However, the gap of knowledge in the transverse impacts of multi-foam-filled or stiffener-reinforced honeycombs is still unfilled. This paper investigates the energy absorption process in large crash boxes applied onto a road maintenance vehicle, exploring four aluminium honeycomb absorbers with design factors like added aluminium foam, corrugated sheet thicknesses, and stiffener reinforcements. The optimised foam-filled honeycomb structures are analysed for four crash scenarios in two different directions; frontal impact (T-direction) and lateral impact (L-direction) subjected to 50 km/hr crash speed. The objective of this research is to identify the most efficient design that achieves a maximum acceleration of up to 20g while absorbing a specific energy of 145 kJ. The FE models were developed in ABAQUS to explore various scenarios related to damage zones, impact energy capabilities, and multi-foam-filled crash boxes. Finally, the lightest design of honeycomb absorbers which can maximise energy absorption while maintaining acceleration below the specified threshold of 20g will be recommended.