面内冲击荷载下半凹角蜂窝的抗冲击特性

The semi re-entrant honeycombs presented unique deformation modes due to its characteristic of zero Poisson's ratio. The impact resistance of the semi re-entrant honeycombs under in-plane impact load was compared with that of the traditional positive Poisson's ratio (regular hexagon) honeycombs and negative Poisson's ratio (re-entrant) honeycombs, and the effects of zero Poisson's ratio on its dynamic performance were revealed. Given cellular geometric parameters (cell wall's aspect ratio), the deformation behaviors of three honeycomb configurations under different impact velocities were analyzed. It is concluded that dominant local deformation band of the semi re-entrant honeycomb is "I" type because of the zero Poisson ratio. According to the one-dimensional shock wave theory, a theoretical formula of the average dynamic crushing strength of semi re-entrant honeycombs was derived and compared with the finite element results to verify its effectiveness. Simultaneously, it was found that the impact resistance of semi re-entrant honeycombs was between regular hexagon honeycombs and re-entrant honeycombs. Therefore, a novel zero Poisson's ratio honeycomb was designed by adding a rib into every cell of the semi re-entrant honeycomb, and its impact resistance was improved. These results provide certain theoretical references for other structural optimization designs.