Numerical modelling of the effect of non-propagating crack in circular thin-walled tubes under dynamic axial crushing

Circular thin-walled tubes have been adopted in vehicular structures to protect occupants and cargo in the events of crash. However, crack initiation on the tubes may pose a great threat to limiting their crashworthiness performance such as the mean crushing force, energy absorption capacity, crush force efficiency and specific energy absorption. This study investigates numerically the dynamic axial crushing of a strain rate sensitive circular thin-walled tube material made from A36 steel hot rolled carbon and modeled with a crack. Six different modeled tube geometries with non-propagating crack are studied and compared with the tube geometry without crack. Results of the crashworthiness parameters, deformation modes, damage morphologies and force-displacement history were obtained. The finite element study shows and establishes the undesirable effect of crack on the overall crashworthiness performance of circular thin-walled tubes.