Large-Deflection Design Technique for Modelling the Collapse of Bus Frames Constructed from Thin Walled Tubes in Roll-Over Accidents.

摘要

A large-deflection design technique is presented for the thin-walled tubular frames which form the superstructure of passenger buses. This procedure could be used at the early stages of bus design so that potential designs can be quickly evaluated to ascertain whether they meet the legislated occupant protection requirements for roll-over accidents. The failure of such thin-walled frames can be quite sudden, the maximum load-carrying capacity not being sustained and a drooping load deflection curve characteristically being exhibited once the maximum load is passed. Consequently this design technique determines the complete load-deflection behaviour of a frame. This is because proper crashworthy design requires a determination of a bus frame's energy absorption capability and suddenness of collapse, not just its ultimate strength. The load-deflection behavior of a two dimensional frame was successfully modelled.