负泊松比结构的三点弯曲性能研究

Research of structure with negative Poisson’s ratio under three-point bending

该文研究了内凹六边形负泊松比结构的三点弯曲力学性能,基于显式动力有限元ANSYS/LS-DYNA建立了该结构的有限元模型,进行了冲击试验仿真,并以单位质量吸能量(SEA)和碰撞力峰值(PCF)为评价指标,探究了胞元结构参数对其性能的影响。研究结果表明,胞元厚度增加或胞元高度降低,可使SEA与PCF同时增加;SEA随着胞元宽度的增大先升高后降低,而PCF则呈相反的趋势;SEA随着胞元内凹角的增大而减小,而PCF在内凹角较小及内凹角约45°时较大。因此,合理选择胞元参数对提高负泊松比结构的弯曲力学性能具有重要意义。

In order to study the crashworthiness of the concave hexagonal structure with negative Poisson ’ s ratio under three-point bending,the effect of cellular structure parameters including the thickness,the width,the height and the inner concave angle on the performance is focused using the explicit dynamic finite element ANSYS/LS-DYNA. The specific energy absorption(SEA)and the peak crushing force(PCF)are adopted as crashworthiness indices. The results show that the SEA and the PCF increase at the same time with the increase of the thickness of the cell and decrease of the cell height;With the increase of the cell width,the SEA increases first and then decreases,while the PCF presents the opposite trend. The SEA decreases with the increase of the inner concave angle. When the inner concave angle is small or about 45°,the PCF is higher. It is inportant to choose appropriate cellular parameters for improving bending performance of the structure.