Crash Response Optimisation of Helicopter Seat and Subfloor

This paper describes the integrated analysis of energy absorbing stages of seat and subfloor in helicopters during a crash landing, and their influence on the occupant's response. Their optimisation, when performed considering both the stages and their mutual interaction, leads to significant reductions of the occupant's injury levels. The study is based on validated numerical models of an anthropomorphic test device, seat and subfloor developed in a multi-body technique. Beyond the optimisations, a series of response surfaces were generated that show the max lumbar spine load, seat stroke and subfloor deflection as functions of mechanical parameters of the seat and subfloor, pointing out the design regions. Different impact speeds were considered. The results suggest that the mechanical properties of the solutions currently adopted for helicopter energy absorption could be easily re-tuned to further improve occupant's protection during a crash landing.