Study on three-point bending behavior of sandwich beams with novel auxetic honeycomb core

Abstract

To further enhance the impact resistance of honeycomb sandwich beams, an auxetic honeycomb core is proposed by introducing rhombic structure into the concave hexagonal honeycomb, thus obtaining a new auxetic honeycomb core sandwich beam (NDH). The bending resistance of NDH is investigated through numerical simulations. The analysis confirms that the NDH has better bending resistance and energy-absorbing properties than the internally concave hexagonal honeycomb sandwich beam (REH). Furthermore, the stable plastic deformation and high energy absorption is closely related to the bearing position and structural parameters. When the punch is directly above the new honeycomb cell (T-position), NDH shows better bearing capacity. In addition, increasing the panel thickness is conducive to enhancing the bending resistance of sandwich beam. The panel thickness arrangement with tf/tb > 1 has better bending resistance than other arrangements under the same total front and rear panel thickness. The composite proportional assessment method (COPRAS) is further used to set affect weights of structure parameters on its bending resistance. It is proved that the bending resistance of NDH may be rapidly enhanced by thickening new honeycomb cells. This research provides some perspectives and methods for the future research on the impact resistance for sandwich panels with novel honeycomb core.