Performance evaluation of reinforced honeycomb structure under blast load

Abstract

Numerical simulations were carried out in this study to explore the response of the reinforced honeycomb sandwich structure with varying cell sizes (7, 10, and 15 mm), node lengths (25, 37.5, and 50 mm), and cell wall thicknesses (0.1, 0.2, 0.3, and 0.4 mm). The honeycomb structure made of aluminum alloy 8011 was subjected to low intensity blast loads by varying masses of TNT (10 g, 15 g, 20 g, and 25 g) and standoff distances (200 mm, 250 mm, and 300 mm). Commercial finite element code LS-DYNA was employed to carry out numerical simulations for both conventional and reinforced honeycomb sandwich structures keeping identical geometrical and blast load parameters. The deformation of the back facesheet was a major parameter to establish blast resistance of the core. Failure mechanisms of reinforced honeycomb were characterized as fully folded region, partially folded region, and clamped region. Reinforced honeycomb sandwich outperformed the conventional honeycomb sandwich structure of identical geometry parameters under similar blast loads. The increase in cell-wall thickness and node length enhanced the blast resistance, whereas the increment in cell size reduced the blast resistance of the reinforced honeycomb sandwich structure.