Parametric study of re-entrant honeycomb cored auxetic sandwich panel exposed to blast loading

Abstract

The protection of military vehicles and critical infrastructure against Improvised Explosive Devices (IED) has become a significant challenge due to frequent terrorist attacks. Sandwich panel with periodic lattice structures as a core material has gained the attention of researchers for blast resistant applications because of their lightweight and high energy absorption capability. Auxetic structures are a class of lattice structures that possess a negative Poisson's ratio (NPR) owing to their topology as a consequence that it undergoes lateral contraction upon compression. Due to this lateral contraction, additional material movement takes place in the impact zone offering more resistance to the localized loading. Near field detonation of explosives imposes localized loading on the structures. The sandwich panel with an auxetic mechanism in the core provides maximum resistance at the point of loading by recruiting more material in the impact zone. The purpose of this study is to numerically investigate the performance of re-entrant honeycomb cored sandwich panels (RHSP) subjected to blast loading. It is followed by a parametric study for optimizing the energy absorption by the core and the force transmitted to the protected structure. Effects on the performance of RHSP for the variation in geometrical parameters, charge mass, and the number of core layers are discussed. Effective Poisson's ratio (EPR) is evaluated for quantifying the lateral contraction in the auxetic structure.