Analyses on the dynamic strength of honeycombs under the y-directional crushing

Based on the cells' collapse mechanisms revealed from the numerical simulations, analytical models are established to deduce the crushing strength of the honeycombs along the y-direction with wide range of impact velocity, which express crushing strength as a function of the impact velocity, the cell size, the cell-wall angle, and the mechanical properties of the base material. The analytical predictions are in good agreement with the numerical simulation results. The optimal cell-wall angle of the honeycomb is analytically obtained as about 45 degrees, which provides a theoretical confirmation on the finding from the numerical simulations. Moreover, a dynamic sensitivity index is proposed to quantitatively evaluate the sensitivity of the honeycombs' crushing strength to the impact velocity, which is expressed as a function of the cell-wall angle and the honeycomb's relative density. It is shown that the dynamic sensitivity of the honeycomb is reversely proportional to the honeycomb's relative density, while the crushing strength of the honeycomb with beta = 45 degrees is the least sensitive to the impact velocity. (C) 2013 Elsevier Ltd. All rights reserved.

基于数值模拟所揭示的胞元坍塌机制，建立了解析模型，以推导在较宽冲击速度范围内蜂窝沿y方向的抗压强度，该抗压强度被表示为冲击速度、胞元尺寸、胞壁角度以及基体材料力学性能的函数。解析预测与数值模拟结果吻合良好。通过解析得到蜂窝的最佳胞壁角度约为45度，这从理论上证实了数值模拟的结果。此外，提出了一个动态敏感度指标，用于定量评估蜂窝抗压强度对冲击速度的敏感度，它被表示为胞壁角度和蜂窝相对密度的函数。结果表明，蜂窝的动态敏感度与蜂窝的相对密度成反比，而β = 45度的蜂窝的抗压强度对冲击速度的敏感度最低。（C）2013爱思唯尔有限公司。保留所有权利。