正交各向异性Kagome蜂窝材料宏观等效力学性能

由于微结构的布局和尺寸的方向性,人造和天然的蜂窝材料都会不同程度呈现各向异性,其中正交各向异性的蜂窝材料较为常见.该文采用桁架模型推导了正交各向异性Kagome单胞蜂窝材料等效刚度和强度的解析表达式,给出了初始屈服函数和近似弹性屈曲强度,讨论了等效刚度与各向异性率和相对密度的关系.等效刚度的解析结果与单胞壁杆采用梁单元建模的刚架模型均匀化结果进行比较,结果令人满意.需要说明的是这类"组合蜂窝"材料具有多功能性和潜在的可设计性,正在受到人们关注.

EFFECTIVE MECHANICAL PROPERTIES OF ORTHOTROPIC KAGOME HONEYCOMB MATERIALS

As a result of the direction of the layout and size of micro-structures,almost all man-made and natural cellular materials are shown anisotropic in varying degrees,in which orthotropic cellular materials are more common. In-plane mechanical properties of periodic honeycomb structures with orthotropic i-sosceles triangle and Kagome cells are investigated in this paper. Effective elastic stiffness and initial yield strength as well as elastic buckling of these metal honeycombs under in-plane compression and shear are derived analytically. Good agreement is shown between the predictions of the effective stiffness from the analytical calculations based on the truss model and homogenization method based on the frame model on the orthotropic honeycomb material. Some issues related to the effective stiffness are discussed,including dependencies on relative density and shape anisotropy-ratio.