双材料曲边内凹负泊松比多胞结构的力学性能研究

MECHANICAL PROPERTIES OF ARC CONCAVE MULTICELL STRUCTURES OF BIMATERIALS WITH NEGATIVE POISSON'S RATIO

  • 摘要: 该文提出一种双材料曲边内凹负泊松比胞元,利用能量法求得等效泊松比和等效弹性模量表达式,所得结果与有限元结果吻合较好。利用所得理论解,讨论了弧角、材料匹配和宽高比对结构等效泊松比的影响。基于提出的双材料曲边内凹胞元,构造了双材料多胞蜂窝结构。利用数值方法讨论了冲击载荷时多胞蜂窝结构的变形失效模式、动力响应曲线、单位体积能量吸收值和单位质量的能量吸收值。研究发现:胞元纵/横向模量比值越大,多胞蜂窝结构的负泊松比效应越明显;相较于单一材料多胞结构,双材料内凹多胞结构压塌时具有截然不同的变形失效模式;相对于单材料结构,双材料结构呈现出优异的吸能特性。

     

    Abstract: A bimaterial arc concave negative Poisson's ratio cell is proposed. The expressions for the equivalent Poisson's ratio and the equivalent elastic modulus are obtained by using the energy method. The present solution is in a good agreement with the finite element results. Using the obtained theoretical solution, discussed were the effects of arc angle, material matching and aspect ratio on the equivalent Poisson's ratio of the multicellular structure. Based on the proposed bimaterial arc concave cell, constructed was a bimaterial multicellular honeycomb structure. Using numerical methods, discussed were the deformation failure mode, dynamic response curve, energy absorption value per unit volume and energy absorption value per unit mass of the multicellular honeycomb structure under impact load. The results show that the higher the ratio of longitudinal/transverse modulus, the more obvious the negative Poisson's ratio effect is. Compared with the single-material multicellular structures, the bimaterial concave multicellular structures have different deformation failure mode during collapse. Compared with the single material structure, the bimaterial structures show excellent energy absorption characteristics.

     

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