Abstract

Temperature effects on tensile and compressive behaviours of an (8,8) boron nitride nanotube (BNNT) were investigated via the molecular dynamics (MD) simulations with the Tersoff potential parameters determined by fitting the MD simulations results to those obtained from the density functional theory calculations. The force-matching method was employed in the fitting process. It was noticed that the failure strain of the BNNT decreases from 33.9% at temperature of 50 K to 26.7% at temperature of 300 K and the critical buckling strain degrades from 5.46% to 3.98%. No obvious yielding occurs before the tensile failure of the BNNTs. A chain-like tensile failure mode was observed prior to complete breaking of the BNNT. In addition, when the BNNT was loaded beyond the critical buckling strain it behaves in a symmetrical buckling mode with a flat cross section near the middle of the BNNT.

No abstract

Abstract

This paper used molecular dynamics (MD) simulations to investigate influences of cone arrangements (including the cone orientation, arrangement pattern and cone spacing) on hydrogen adsorption of open-tip carbon nanocone (CNC) arrays at temperatures of 100 and 300 K. To consider curvature effects for the cone structure of the CNCs, the curvature-modified Lennard-Jones potential parameters were adopted to describe the interactions between the hydrogen and carbon atoms. It was found that the cone orientation (aligned, opposite, and alternate) does not have obvious influences on hydrogen adsorption of the CNC arrays. The arrangement pattern (square and triangular), however, had significant influences on the hydrogen adsorption. The square-patterned CNC array was noticed to have higher storage weight percentage than the triangular-patterned one. Regarding to the influences of cone spacing, the storage weight percentage grew with the increase of the cone spacing and arrived at a stable value as the cone spacing reached a certain critical value. The influences cone arrangements could be ascribed to repulsive effects, which are evident as cone spacing become narrow.