Structural response of monolithic and multi-stacked AA2014-T6 sheet specimens subjected to shock loading

Abstract

Experimental and numerical investigations of the shock response of AA2014-T6 sheets are presented in the current study. A double-stage shock loading apparatus is utilized for loading the simply supported specimens under the shock loading. The experiments are performed on two different sheet thicknesses i.e., 1 mm and 2 mm. The spatial out-of-plane displacement of the specimens is obtained using 3D digital image correlation (DIC) technique. ABAQUS/Explicit is utilized for finite element (FE) modelling and simulating the shock loading event. A modified loading function is incorporated in the FE model to approximate the change in the specimen loading area and shock loading magnitude for the deformable specimens. The experimentally and numerically obtained out-of-plane displacement of the specimens are compared and agreement between both is quantified using Russell error technique. A series of experiments are conducted to investigate the effect of change in shock loading magnitude on the deformation phenomenon and corresponding energy dissipation. Alloy sheet of 2 mm thickness is observed to be better shock resistant than 1 mm sheet as the plastic dissipation energy per unit mass is higher for 2 mm thick sheet. Additionally, the shock behaviour of layered targets is also investigated for effective thicknesses of 2 mm and 3 mm. The performance of monolithic sheet of 2 mm is observed to be better than layered configuration of (1 + 1) mm. For the effective thickness of 3 mm, the order of decreasing shock performance is observed as (2 + 1) mm, (1 + 2) mm, and (1 + 1 + 1) mm.