Impact energy absorption characteristics of single-walled carbon nanotubes

The excellent mechanics characteristics of carbon nanotubes make them potentially applicated in energy absorption, however, it is still difficult to be verified by nano-scale experiments. By integrating the principle of molecular structural mechanics into the nano-scale finite element method, the fracture process of single-walled carbon nanotubes (SWCNTs) under axial impact loads was simulated based on the principle of impact dynamics. The parametric structural model of SWCNTs was built by APDL language in ANSYS software. Meanwhile, the constitutive equation of C-C bond was obtained by the modified Morse potential function. According to the failure strain criterion, the energy absorption capability of SWCNTs with different diameter, length and chiral was investigated. The proposed simulation method can effectively predict the locations and directions of fracture in SWCNTs, and the growth process of rupture could also be visualized dynamically. It is demonstrated that the specific energy absorption of SWCNTs is much higher than that of similar tubes manufactured by other materials. In addition, the energy absorption of zigzag SWCNTs is higher than that of the armchair SWCNTs.