Out of Plane Punch of Aluminum Hexagonal Honeycomb Using Flat Nose and Spherical Projectiles

The 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, projectile shape and projectile diameter, specimen height, and the loading speed on the perforated zone and the absorbed energy are studied. The perforated zone of the honeycomb has not perfectly the same shape of the projectile, 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 projectile shape from a flat nose to a sphere decreases the absorbed energy approximately to the half value. Multiplying the projectile diameter by two increases the mean crushing load of the metal hexagonal honeycomb less than four times. On the other hand, it was shown that the honeycomb local energy absorption capacity is not perfectly independent of sample height and loading speed. Furthermore, based on the modified Wierzbicki’s model in the global loading, a simple theoretical model for the estimation of the mean crushing load of a metal hexagonal honeycomb loaded by a flat projectile is presented. Good agreement between the theoretical and experimental results is illustrated.