FE Investigation on Behaviour of Al-Alloy Tubes Subjected to Axial Impact

For designers, it is a challenging task to design or develop an efficient product and shock absorber which also fulfils the primary requirements in terms of crashworthiness, lightweight, material optimization, and of course economy too. Under impact loading, the thin-walled cylindrical tubes are employed as primary energy-absorbing elements in automotive and some other industries. Therefore, in the present paper, the performance of the aluminium tubes was investigated against their varying thickness (2 and 3 mm) and length (130–170 mm) under impact loading. The effect of variation of length-to-diameter ratio of the tube has been studied. The numerical simulations were carried out using Abaqus Explicit. The metal-plasticity constitutive model was employed for modelling the ductile aluminium alloy. The tubes were fixed at the bottom during the impact, and a known mass was dropped on the other end of the tube with a velocity of 10 m/s. The axial crushing length of the specimen was found to be directly proportional to the length-to-thickness (h/t) ratio. The maximum value of axial crushing length was found to be 151.6 mm for a tube-5 which has 2 mm thickness, 170 mm length, and 50 mm diameter. The initial peak crushing force (IPCF) of the 2 mm cylindrical tube specimens was 35–40% lesser than the 3 mm thick cylindrical specimens. It was found that the specific energy absorption was increased with an increase in the thickness of the tube. The number of folds was also increased under impact with an increase in the tube length.