Ballistic performance and energy dissipation characteristics of cylindrical honeycomb sandwich structure

Abstract

The energy absorption (EA) and ballistic behaviour of the cylindrical sandwich shells, which comprised of honeycomb core (AL-3003 H18) and cylindrical face sheets (AL-1100 H12), were investigated by carrying out experiments and numerical simulations. Two distinct nosed shapes, ogive and hemispherical shape impactor of mass 52.5 gram, length 50.8 mm and diameter 19 mm, were impacted normally at the outer curved surface of the sandwich structure. A compressed air gun was used for experiments and the incidence velocities of both the impactor were kept within the range of 50 -146 m/s. The results in the form of ballistic limit, local and global deformation and the failure modes of the sandwich structure were reproduced through numerical simulations which were carried out through commercially available finite element code Abaqus/Explicit. Johnson cook material model was used for the face sheet whereas for the honeycomb core and the adhesive layers, ductile damage material model was employed. The validated numerical model was further extended to discover the influence of facesheet thickness, side length, curvature and cell wall thickness on the ballistic resistance, deformation, failure mode and EA of the sandwich shell structure. The influence of the face sheet thickness on the performance of the cylindrical sandwich structure was more significant compared to the honeycomb core geometric parameters. However, decreasing the side length, and increasing cell wall thickness and curvature enhanced the EA and ballistic resistance marginally.