Performance Analysis and Multilayer Design of Curved Honeycomb Sandwich Panels with Different Cell Arrays Under Projectile Impact

Abstract

The cell array type significantly affects the global stresses in curved honeycomb sandwich panels. In this study, the curved sandwich panels with the out-plane honeycomb core (COP) and the in-plane honeycomb core (CIP) are proposed. Their local impact resistance is numerically investigated using finite element simulation calibrated with air cannon test results. Various impact scenarios including different projectile diameters, different impacting velocities, angles, as well as locations are considered. The performances of the COP and CIP panels with similar overall mass and relative density are compared by evaluating their impact histories and energy absorption properties. It is demonstrated that the CIP panel shows improved impact mitigation and energy absorption property under local impact. However, its overall displacement is significantly larger than that of the COP panel. Based on the impact behavior of COP and CIP panels, the hybrid two-layer structures (HOI and HIO) are designed. It is found that the HIO panel shows an increase in energy absorption of approximately 3% over the COP and CIP panels and a reduction in the overall displacement of at least 28% over the CIP panel. Moreover, HIO configuration with the thinner cell wall thickness of the upper core demonstrates improved impact mitigation.