Papers by Author: Moones Rahmandoust

Abstract: In this study, single-walled carbon nanotubes were generated in their perfect state as finite element models in the MSC.Marc software. The buckling behaviour and resonant frequency modes of the two limiting cases of carbon nanotubes, i.e. the armchair and zigzag models, were studied. The obtained results were compared with the classical analytical solutions related to a similar continuum structure of a hollow cylinder. The buckling behaviour of single-walled carbon nanotubes under cantilever boundary conditions proved to be almost identical to the prediction of the classical Euler equation. Furthermore, there was very good agreement between the analytical and finite element results of the studied single-walled carbon nanotubes; though the achieved value of the first mode of frequency, obtained from the finite element results, was more accurate than the higher modes.

Abstract: In this study, a finite element model of a representative volume element that contains a hollow and filled single-walled Carbon nanotube (SWCNT) in two case studies was generated. It was assumed that the nanocomposites have geometric periodicity with respect to local length scale and the elastic properties can be represented by those of the representative volume element (RVE). Elastic properties in agreement with existing literature values for the Carbon nanotube and the matrix were assigned. Then for the two case studies, the tensile test was simulated to find the effect of the geometry, i.e. the volume fraction of matrix and SWCNT's properties variation, on the effective Young's modulus of the structure. In another approach, by applying perpendicular loading to the tube direction, the effect of matrix volume fraction on the transverse Young's modulus was studied. The investigations showed that for both RVEs with filled SWCNT and hollow SWCNT, the effective Young's modulus of the structure decreases approximately linear as the matrix volume fraction increases. The value of Young's modulus of the RVE with a filled Carbon nanotube was obtained to be higher than the RVE with the hollow Carbon nanotube. In addition, by increasing the tube diameter, the effective Young's modulus of the structure increases and the transverse Young's modulus decreases approximately linear for filled tubes but this parameter remains rather constant in the case of the hollow tube by increasing the matrix volume fraction.