Stress distribution of carbon nanotube reinforced polymer matrix composites under tensile stress

Abstract

A cylindrical representative volume element model of polymer nano-composites reinforced by carbon nanotubes under a fixed tension stress was developed. The stress distribution in each layer of carbon nanotubes was numerically studied through developing a shear lag model. Finite element analysis was adopted to validate the results obtained by shear lag analysis. The effects of layer numbers, aspect ratio, content of carbon nanotubes and three kinds of matrix materials of epoxy resin, nylon and polymethyl methacrylate on the stress distribution in each layer of carbon nanotubes were analyzed. The results show that the stress distribution in graphene sheets of carbon nanotubes is significant influenced by layer numbers and the aspect ratio of carbon nanotubes under a fixed tension stress. The saturation stress of carbon nanotubes is decreased with the increase of the layer numbers and the value correlated with the number of layers. Single-walled carbon nanotubes are observed to perform the best utilization of its properties. It is found that the effective length is increased with the increase of the aspect ratio of carbon nanotubes. Significant increase of the saturation stress and decrease of the effective length of carbon nanotubes are observed respectively with the decrease of the content of carbon nanotubes. It is also indicated that different polymer matrix materials play little effect on the stress distribution in carbon nanotubes.

Keywords

• carbon nanotube
• polymer matrix
• stress distribution
• shear-lag model
• finite element met-hod