Mechanical behaviors of inner and outer sidewalls of honeycomb cores subjected to out-of-plane compression

Abstract

The mechanical behaviors of honeycomb cores subjected to out-of-plane compressive loading were studied based on the deformation of cell walls. Four types of honeycomb structures, with and without panels, were experimentally, theoretically, and numerically investigated, respectively. In addition to the deformation of outer sidewalls, the stereovision three-dimensional digital image correlation (3D-DIC) method was first applied to determine the deformation process of the inner sidewalls. A coaxial 3D-DIC was developed to obtain the full-field displacements and strain distributions of the inner sidewalls. The compression strength of the structures was predicted successfully by the theoretical elastic buckling strength. Moreover, the onset of the damage process was simulated with finite element calculations, which agreed well with experimental data. Therefore, this study provides a better understanding on the behavior of honeycomb structures from the deformation of outer and inner surfaces.