Numerical investigation of stepped concentric crash tubes subjected to axial impact: The effects of number of tubes

The purpose of this study is to examine the energy absorption characteristics of stepped concentric crash tubes subjected to an axial impact load. The stepped concentric tubes with circular cross section are analyzed numerically by using LS-DYNA. The total mass and volume are kept constant when the number of tubes is increased. As the number of concentric tubes is increased, it is observed a smooth transition of the peak forces during the impact. Also increasing the number of tubes reduces the maximum peak force and leads to a reduction of the initial peak force due to lower wall thickness of the tubes.