Synergistic energy absorption in the axial crush response of filled circular cell honeycombs

In the present investigation, the axial static crush response of circular cell, filled honeycombs is studied. Polycarbonate honeycombs with circular cells are used as the base material. Polyurethane, a soft elastomer is used as the filler material. Filled 3-cell, 7-cell and 19-cell honeycombs were subjected to uniaxial, quasi-static, out-of-plane compressive loading. The experimental results show a synergistic energy absorption event, leading to an amplification of crush energy absorption in the filled honeycombs due to a change in the deformation mode (in comparison against unfilled honeycombs). Moreover, it is seen that the initial failure is a stable collapse unlike the abrupt first failure seen in unfilled honeycombs. An explicit finite element solver is used to quantitatively understand the experimental results, thus validating its usefulness as an engineering design tool.