A finite element analysis of a lightweight blast proof sandwich structure

Abstract

The objective of this study is to analyze the performance of a blast-proof composite material upon impact loading subjected under blast. The material that is currently being used for blast protection is armored steel. Although it has high strength and toughness its strength to weight ratio is low which limits the applications of armored steel. Hence to overcome this limitation a sandwich composite was considered as an alternative to steel for blast protection. The sandwich composite had the top layer as Ceramic matrix composite to withstand high temperatures, core as a honeycomb structure and bottom layer as polymer matrix composite to stop the core from deforming excessively. The composite was modeled in Abaqus/Explicit and with the help of literature, the blast load was simulated as a triangular pulse in the form of the number of Tri Nitro Toluene (TNT) exploded. The performance of the composite was investigated by analyzing the amount of energy absorbed by the material upon impact and was compared with the performance of armored steel. The results showed that the sandwich composite was able to perform better than or equal to steel up to the explosion of 3 kg of TNT. But beyond 3 kg TNT its performance degrades and becomes lower than steel. Beyond explosion of 3 kg TNT the top layer, Ceramic matrix composite fails which exposes the inner core to the blast environment. As the amount of explosive increases, the core starts to undergo excess deformation and after a certain load, the deformation exceeds the limit of the bottom layer leading to the failure of the polymer matrix composite. Therefore, the proposed sandwich composite performs better than steel within a given working condition but beyond its working condition, its performance degrades resulting in failure of sandwich composite.