A new trigger mechanism for crushing square CFRP tubes

A low initial peak crushing force or a high crushing force efficiency of a vehicle crashworthy structure are desirable to minimise the occupants’ injury during a vehicle crushing deceleration. The aim of this study is to reduce the initial peak crushing and increase the energy dissipation of square CFRP tubes and aluminium sheet-wrapped square CFRP tubes. Manufactured platens with cutting blades were employed as new external trigger and energy dissipated mechanisms. These platens with cutting blades were specially designed to simultaneously cut and crush CFRP tubes to reduce the initial peak crushing force and achieve stable mixed deformation modes (cutting and progressive crushing). The results of tubes cut and crushed by platens with blades are compared with those of tubes crushed by only flat platens. It was found that CFRP tubes or aluminium sheet-wrapped CFRP tubes cut and crushed by platens with blades have a low peak crushing force, a high crushing force efficiency and a large mean crushing force and a high energy absorption compared with those for tubes under only crushing by flat loading platens.