On the blast response of sandwich aerospace composites

Abstract

Aircraft floors are a typical example of an advanced sandwich composite structure. Although not structurally loaded due to flight loads, they play an important role on passenger survivability. Additionally, due to their connection with the lower aircraft structural components, in the case of an extreme loading scenario, such as an explosion in the aircraft cabin, it is possible to transfer loads beyond the operational levels to the airframe. The present paper aims to compare the contribution of different core configurations to the accelerations exerted to the frame due to blast loading by numerical analysis. Two different core materials are investigated, bearing similar densities, namely aluminium and Nomex paper honeycomb. The hydrodynamic code LS-DYNA is used in order to model the fluid structure interaction associated with blast loading by an ALE scheme and strain rate dependent material properties are incorporated. The skins of the considered aircraft sandwich floor are made of GFRP. Accelerations are extracted on the connection points of the specified floor. Moreover, the damage modes of the structure’s constituents are considered (skin, core) and direct comparisons are made on blast energy absorption capacity.