Experimental and Numerical investigation of the Hole Effect on Collapse Properties of End-capped Conical Tubes under Axial Quasi-static Loading

In this study, the energy absorption characteristics of steel end-capped conical tubes, perforated in various states, under quasi-static axial loading have been studied both experimentally and numerically. In the experimental section, steel alloy was identified after making the ready cones. In order to determine the mechanical properties, dumbbell-shaped samples cut by wire-cut from the cones and tensile test was performed, then the stress-strain curves were obtained for them. The conical structures were simulated using finite element software LS-Dyna and the results were compared with data from experimental tests. There was good agreement between experimental and numerical results. In this paper, 48 various states were investigated and collapse features were extracted and compared. These 48 states include three angles for cone edge, four thicknesses and four different modes in terms of number of holes, so in this way mechanical behavior of perforated steel end-capped conical absorber in various states were studied. Studies show that increasing the number of holes in the absorber's body reduces the maximum force and leads to an increase in crush force efficiency. According to the results, perforated conical absorbers are a good alternative for the same samples with no holes.