Energy absorption properties of dimpled circular tubes: Experimental and numerical studies

As an exemplary energy absorption structure, thin-walled metallic tubes have been extensively studied. Introducing dimple defects into the tube wall can induce the desired deformation in thin-walled metallic tubes to enhance their energy absorption performance. Existing research has only discussed dimpled tubes with relatively thin wall thicknesses and shallow dimples, which is insufficient to meet the demands of widespread applications. This study introduces two novel tubular structures by incorporating predefined dimples into the walls of smooth tubes. Through finite element simulation and experiment, the influence of wall thickness, dimple aspect ratio, and the orientation of the dimples on the energy absorption capacity of the structures is parametrically analyzed. A comparison with traditional smooth tubes is also conducted. The results indicate that the wall thickness, dimple aspect ratio, and orientation of the dimples have significant effects on reducing the initial peak force, enhancing specific energy absorption, and improving structural stability. By appropriately selecting geometric parameters, energy absorption tubular structures adaptable to various application scenarios can be designed. The two novel tubular structures proposed provide new design insights for the study of energy absorption in thin-walled metallic tubes.