Investigation of length and chirality effects on Young’smodulus of heterojunction nanotube with FEM

In this paper, the influences of length and chirality on the Young’s modulus of hetero-junction carbon nanotubes (HJCNTs) are described. A three-dimensional finite element (FE) model for HJCNTs is proposed. The model development is based on the assumption that carbon nanotubes, when subjected to loading, behave like space-frame structures. The bonds between carbon atoms are considered as connecting load-carrying members, while the carbon atoms as joints of the members. The elastic moduli of beam elements are considered by using a linkage between molecular and continuum mechanics. Investigation includes two cases, variable length with constant chirality and variable chirality with constant length. It is found that the choice of length and chirality significantly affects the calculation of Young’s modulus. The results show that in the case of constant length, with increased chirality, the Young’s modulus of HJCNTs increases and in the case of constant chirality, with increased length, the Young’s modulus of HJCNTs decreases, but this decrease is weak. The presented results demonstrate that Young’s modulus of HJCNTs with chirality more than ((5, 5), (10, 10)), is larger than SWCNTs with same and larger chirality. The presented results demonstrate that the proposed FE model may provide a valuable tool for studying the mechanical behavior of hetero-junction carbon nanotubes (HJCNTs) and carbon nanotubes.

Hetero-junction carbon nanotubes (HJCNTs); Young’s modulus; Carbon nanotubes; Finite element model; Chirality