Elastic properties of single-walled carbon nanotube clusters: Dependence on hydrostatic pressure

•A relation for collapse pressure as a function of SWCNT diameter was determined.•All five elastic properties of SWCNT clusters in zero pressure were calculated.•The impact of hydrostatic pressure on the elastic properties was considered.

Carbon nanotube (CNT) clusters have different properties from free-stand CNTs. This paper aims to investigate the effect of hydrostatic pressure on the elastic properties of single-walled carbon nanotube (SWCNT) clusters composed of armchair SWCNTs of diameters below 2 nm. A simple representative volume element in a periodic cell was constructed. Molecular mechanics (MM) was used to optimize the geometry and to evaluate the elastic properties in different pressure states. The results showed that the collapse pressure of SWCNT clusters varies exponentially with increasing the SWCNT diameter, that all elastic properties increase with the hydrostatic pressure rise, except the transverse Young’s modulus, and that the external pressure has the most impact on the out-of-plan shear modulus.