Testing and modelling of stiffened aluminium panels subjected to quasi-static and low-velocity impact loading

The behaviour and failure of stiffened panels made of the aluminium alloy AA6082-T6 is investigated under quasi-static and low-velocity impact loading conditions. The strain rate and inertia effects are found to be negligible suggesting that quasi-static tests might be representative for low-velocity impacts where a large mass is placed on the impactor. A simplified approach to the finite element modelling of aluminium panels under impact loading, including a regularised failure criterion, is proposed and validated against the experimental data. The effect of mesh size is investigated with shell elements of various sizes in the range from 1 to 5 times the thickness. A good correlation is obtained between experiments and simulations for fine meshes, while large shell elements have difficulties to initiate and propagate properly the observed cracks. (C) 2017 Elsevier Ltd. All rights reserved.