Blast energy absorption of recyclable beverage cans

Before designing the sacrificial cladding structure in full-scale the knowledge of the energy absorption of an individual core member (empty cola can) is very important. Small-scale axial impact tests (drop weight test) and close-range free air blast tests have been conducted (with 20g of C4 with a stand-off distance of
30cm) to understand the crushing behaviour of the empty cola cans. To conduct such axial impact tests and air blast tests special small scale test set-ups were designed and manufactured. Using these test setups different parameters such as initial impact velocity, inertia of the outer skin, surface roughness, area of the skin plate on the energy absorption of the inner core were studied. In order to understand the crushing behaviour of the cola can in detail numerical models were developed for impact and blast loading conditions. Results from the impact simulations correlated well with the experimental results. However, the results from the blast simulation using experimentally measured pressure-time histories
showed much higher deformation length of the cola cans which is observed in the experimental results. These results motivated us to study the interaction of the blast pressure waves with the blast experimental set-up. The numerical study of the interaction of pressure waves with the experimental set-up was carried out using “Hydrocodes”. The results from the Hydrocodes simulation showed the effect of diffraction and the ground reflection on the deformation length and the corresponding energy absorption of the empty cola cans. Based on the results of Hydrocodes simulation the de-coupled analysis was carried out in ABAQUS V6.7-3 using the experimentally measured pressure-time histories. To capture the strain rate sensitivity of the cola can the “Johnson-Cook” material model was used. The results from these analyses were compared with the experimental data. Finally this study also shows the effect of initial geometric imperfections on the energy absorption of empty cola cans.