Investigation of different geometric parameters effect on axial crushing of thin-walled conical tubes

Thin-walled structures have always been considered by designers as components with excellent energy absorption and high strength to weight. These structures are made in different shapes and geometries. Conical tubes are one of the types of thin-walled structures that deform the plastic and absorb energy under loading in different ways. The energy absorbed through plastic deformation depends on various factors such as the geometry of the tube, the volume, the angle of applied load and the materials. In this paper, a comprehensive study has been performed on thin-walled conical tubes as energy absorbers using numerical simulations. For this purpose, the effect of various parameters including the presence of the cap at the end of the tube, annular and longitudinal grooves, the creation of holes on the tube wall and loading angle has been investigated on the crushing mode and energy absorption. The results show that although the presence of annular, longitudinal grooves and creating holes on the tube wall leads to reduced energy absorption, but it causes a stable collapse and reduces the maximum crushing load and prevents the suddenly applied load to occupants and the main part of structures Also, the results showed that the number of holes did not have a significant effect on the collapse and the behavior of the load-displacement curve; while the shape of the hole geometry affects the collapse mode and the mean crushing load.