Assessment of Energy Absorption and Crushing Performance of Perforated Thin-Walled AA6061-O Tubes with Irregular Holes Under Axial Compression Loading

Thin-walled tubes have a significant role in increasing the absorption of energy in an energy-absorbing system. Due to ease of production and non-complex geometry, holed thin-walled tubes are a proper candidate for use in energy-absorbing systems. This study presents a new irregular hole arrangement in the cylindrical thin-walled tubes made of AA6061-O to improve the energy absorption capability in terms of total absorbed energy (E_t), specific energy absorption (SEA), the initial crushing force (ICF), and the ratio of initial crushing force to mean crushing force (MCF). Aiming this, the Taguchi design of experiment method was used to determine optimum levels of the input parameters including the number of hole rows, the number of holes in each row, the diameter of the small hole, and the diameter coefficient. To examine the efficiency of the new proposed hole arrangement, the crushing performance of the optimum irregular sample (C3) was compared with cylindrical tubes without holes (S1) and with regular holes (T1). The results illustrated that the C3 tube has a higher SEA of 19% and 26% compared to S1 and T1 tubes, respectively. On the other hand, the ratio of ICF to MCF in the C3 tube decreases by 17% and 19%, respectively, compared to S1 and T1 tubes.