A theoretical and experimental study on metal hexagonal honeycomb crushing under quasi-static and low velocity impact loading

In the study of honeycomb crushing under quasi-static loading, two parameters are important; the mean crushing stress and the wavelength of the folding mode. On the other hand, the kinetic energy absorbed by the honeycomb is investigated in the impact loading. In this paper, through fully considering the cylindrical curvature effects and implementing the energy method, a new theoretical model for the estimation of the mean crushing stress and the wavelength of the folding mode of the metal hexagonal honeycomb is presented. Afterwards, developing this static model to the dynamic state, a theoretical model for study of the behavior of these energy absorbers, in the low velocity impact loading, is proposed and the required initial velocity of the impactor, for creation of the desired folding length in these structures, is determined, analytically. The presented theoretical models have been compared with experimental results obtained from experiments on three kinds of honeycomb with the various minor diameters and thicknesses of the cell walls under quasi-static and low velocity impact loading in the axial direction. Excellent correlation has been observed between the theoretical and experimental results.