Stress Transfer Characterization at Fiber Break in Carbon Nanotube-Reinforced Composites

The present work deals with the study of stress distribution in the vicinity of a broken carbon nanotube (CNT) in a CNT-based nanocomposite. A square representative volume element (RVE) having nine uniformly spaced CNTs in the matrix has been considered for the analysis. Three dimensional finite elements (FE) analysis has been carried out for the square RVE and the effect of a broken CNT on the adjacent CNTs and matrix has been studied. CNTs and matrix in a RVE are considered linearly elastic, isotropic, and homogeneous materials and a perfect bonding is assumed between the CNT and matrix. The axial normal stress in the broken CNT, interfacial shear stress at the interface of the broken CNT and matrix, and axial normal stress in the adjacent CNTs has been calculated for different volume fractions and the effect of volume fraction on the stress redistribution has also been investigated. Results obtained from the present study conclude that the ineffective length of the broken CNT is dependent on the volume fraction of the composites as well as on the type of matrix materials. Stress concentration in the vicinity of the broken CNT is also influenced by the fiber volume fraction and the type of matrix materials.