Size- and shape-dependent effective properties of single-walled super carbon nanotubes via a generalized molecular structure mechanics method

A super carbon nanotube (SCNT) is a cylinder rolled up from a super graphene (SG) layer which is built by connecting Y-type single walled carbon nanotube (SWCNT) junctions. The unique structure of the SCNT results in two determinants of radius of the SCNT, the number of junctions along the circumferential direction of the SCNT and length of the constituent SWCNTs. The mechanical behaviors of the SCNTs are investigated by using a generalized molecular structure mechanics (MSMs) method which is generated by combining the MSM method with the failure criterion of the carbon–carbon bonds. The results show that number of junctions along the circumferential direction of the SCNTs and length of the constituent SWCNTs both have obvious effect on deformation process of the SCNTs. Moreover, the size- and shape-dependence of the Young’s modulus and Poisson’s ratio of the SCNTs are calculated by the generalized MSM method. Exact relations between the mechanical properties of the SCNTs and their size which can reasonably fit the computed results are provided.