Analysis of in-plane elastic modulus for a hexagonal honeycomb core: Effect of core height and proposed analytical method

In this study, the effect of height h of a hexagonal honeycomb core on the elastic modulus was studied by using numerical results of finite element method (FEM). The cell walls of a honeycomb subjected to in-plane loading are deformed in the height direction due to the effect of Poisson’s ratio. Since these deformations differ between adjacent cell walls if they are not joined along their common edge, the in-plane stiffness should be analyzed in three-dimensions to ensure that deformations in the height direction are considered. In addition, it is shown that the elastic modulus of honeycomb core is independent of height under the plane strain condition. Based on this, an equation is proposed that can be used to calculate the elastic modulus in the direction of the vertical cell wall E2 from the elastic moduli under the plane strain condition. The validity of this equation was verified by the results of a FEM analysis.