Improving energy absorption of AA6061 holed thin-walled cylindrical tubes

Thin-walled tubes play a significant role in increasing the energy absorption in energy absorbing systems. Holed thin-walled tubes are a suitable option for use in these systems due to the ease of production and the lack of geometry complexity. In this paper, a new geometric pattern for holed thin-walled cylindrical tubes made of aluminum alloy 6061 is presented, to improve the energy absorption characteristics. To this aim, the Taguchi design of experiment method has been used to find the optimal levels of the geometrical parameters of the tube to achieve the maximum energy-to-weight ratio and the minimum effective equivalent strain. The number of rows of holes, the number of holes in each row, the diameter of the small hole and the diameter coefficient of the small hole were considered as the geometric (input) parameters of the tubes. The initial crushing force, the total absorbed energy, the ratio of energy to weight and the ratio of the maximum initial force to the average force were compared for the optimal layouts. Examining the results showed that the arrangement of the holes in the middle with 3 rows of holes, 8 holes in each row, diameter of the small hole of 5 mm and the diameter coefficient of 1.2 (the large diameter is 6 mm) will lead to the best energy absorption result.