Analysis of in-plane mechanical response of hexagonal honeycomb core: Effect of node bond adhesive and proposed analytical method

Abstract

In this study, the development of an analytical model to predict the homogenized in-plane stress-strain behavior of hexagonal honeycomb core under large deformations is presented. Unlike in traditional models, the detailed geometric features of a commercial hexagonal honeycomb core cell such as cell wall curvatures, node bond adhesive layer, and node bond fillets are included in the analysis. In the analytical model, the honeycomb core is modeled to be of unit thickness under plane-strain conditions, and classical beam theory is applied to model the behavior of the cell walls. The homogenized stress-strain curves predicted by the analytical model for uniaxial tension loading along the transverse and ribbon directions are compared with test data for a commercial hexagonal honeycomb core (Hexcel HRP-3/8-4.5), as well as the predictions from a finite element model. The predictions of the proposed analytical model are in good agreement with the test data and predictions of the finite element model.