Longitudinal shear strength and failure process of honeycomb cores

The longitudinal shear deformation behavior and failure process of aluminum alloy honeycomb cores are investigated by the single block shear test in this paper. The load-displacement curve that is obtained from the shear test at the room temperature shows that the shear load increases to a peak value and then tends rapidly to a constant. The shear deformation process of honeycomb cores may be approximately categorized into four stages, namely elastic deformation, plastic deformation, fracture of cell wall and debonding of honeycomb cores/ facesheets. On the other hand, the longitudinal shear strength of honeycomb cores also is studied by experiment and theory. According to the elastic shear buckling theory of cell wall and the compatible uniform strain field assumption, it is found that the theoretical result is more acceptable, although it is only about half of the experimental result.