Finite element simulations of blast loading on sandwich structure

Abstract

The threat posed by terrorist activities and explosive devices necessitates the continuous evolution of protective technologies, including blast-resistant materials and structures. Specifically, in the context of footwear for soldiers exposed to the risks of landmines and other explosive devices, optimizing blast-resistant sandwich structures is crucial. These structures typically consist of layered compositions designed to absorb shock waves and attenuate pressure generated by explosions. The core materials used in these structures are, generally, honeycomb, and auxetic/meta-structured cores which offer distinct advantages in terms of energy absorption and structural stability. Among the various cores, honeycomb have gathered attention for blast loading due their high energy absorption characteristics. There are various length scales associated in these honeycomb such as cell wall thickness, cell size. In addition, the loading orientations (in-plane and out-of-plane) has also shown to influence the energy absorption greatly. In order to determine, the optimum shape, size and loading direction for specific loading conditions, a detailed study is needed. There are few studies undertaken in this direction, but a very little efforts has been made to understand the deformation behavior of sandwich structure subjected to near-field blast. Therefore, continuum simulations of near-field blast loading have been undertaken in this study. Results shows that thinner shells are better in attenuating pressure but in turn absorbs lesser energy hence optimum thickness is found, further the decrease in cell size leads to greater energy absorption and effective pressure attenuation capability, additionally it is found that the combination of square out-of-plane honeycomb and auxetic in-plane honeycomb cores shows better blast resistance than structures with only in-plane auxetic honeycomb cores, in terms of both energy absorption and pressure attenuation, specifically when the in-plane auxetic honeycomb core is placed on the blast side.