Boron nitride nanotubes (BNNTs) possess superior thermal conductivity and
mechanical/electrical properties, and are a suitable and favourable reinforcement for
binanocomposites. Experimental studies on nanoscale materials are time-consuming,
costly, and require accurate implementation. Therefore, a three-dimensional finite
element (FE) model of a space-frame structure is proposed for BNNTs, which is
based on molecular structural mechanics. The effects of length, chirality, diameter,
and defect on the elastic moduli of BNNTs are investigated. The results show that
defects in the nanotubes decrease the mechanical properties. The values of the
Young’s modulus and shear modulus of BNNTs without defects change from
to
and
from
to
,
respectively. It is found that, with increasing chirality and radius of BNNTs, the
Young’s modulus and shear modulus increase. As the length of zigzag and armchair
BNNTs increases, the Young’s modulus increases and the shear modulus decreases.
Also, it was observed that by using the finite element method (FEM) based on
molecular dynamics, one can accurately determine the mechanical properties of
BNNTs. The results demonstrate that the proposed FE model is a valuable tool for
studying the mechanical behaviour of BNNTs.
Keywords
elastic moduli, boron nitride nanotube, chirality, length,
finite element method