Strength enhancement of aluminium honeycombs caused by entrapped air under dynamic out-of-plane compression

The out-of-plane crushing behaviour of aluminium hexagonal honeycombs containing different percentages of holes (i.e., the fraction of penetrated cells to the total) was extensively investigated over a wide range of strain rates where each test was conducted at constant compression velocity. Strength enhancement due to the increase of the strain rate and the entrapped air was studied. It is found that the strain hardening of honeycomb structures...