Document Type : Research Article
Mechanical Engineering Department, Amirkabir University of Technology, Tehran, Iran
Energy absorption capacity of metal hexagonal honeycomb under out of plane local quasi-static loading is investigated, experimentally. Effects of geometrical parameters, such as the cell size and wall thickness of the honeycomb, punch shape and diameter, specimen height, and loading speed on the perforated zone and the absorbed energy are studied. Perforated zone of the honeycomb has not perfectly the same shape of punch, but it can be assumed as a skew polygon or ellipse, extended in the direction of the honeycomb dual walls. Results show that changing the punch shape from flat nose to a sphere decreases the absorbed energy approximately to the half value. Multiplying the punch diameter by two increases the mean crushing load of the metal hexagonal honeycomb less than four times. The honeycomb local energy absorption capacity is not perfectly independent of sample height and loading speed. Increasing the height of the core decreases slightly the energy absorption capacity of metal hexagonal honeycomb under out of plane local quasi-static loading. Difference between the perforated zone and punch cross section increases by increasing the loading speed, as the polygon changes to a rhombus and the difference between the major and minor diameters of ellipse increases. Finally, a theoretical model for the estimation of mean crushing force of a metal hexagonal honeycomb loaded by a flat punch is presented.