Mean in-plane plateau stresses of hexagonal honeycomb cores under impact loadings

Double-walled hexagonal honeycomb cores (DHHCs) are important cushioning materials and their configuration parameters and impact velocities have effects on their impact properties. In this paper, the finite element (FE) model by using ANSYS/LS-DYNA was to investigate the relations between configuration parameters of DHHCs and their mean in-plane plateau stresses at impact velocities from 3 to 250 m/s. When all configuration parameters are kept constant, mean in-plane dynamic plateau stresses are proportional to the square of impact velocities. For the given impact velocity, mean in-plane dynamic plateau stresses are related to the ratios between cell wall thicknesses and cell edge length by power laws, to cell edge length ratios by exponential laws and to expanding angels by conic curves. Based on the FE calculated results, many empirical formulas and a feasible method to be used to calculate mean in-plane dynamic and static plateau stresses of DHHCs are suggested.