Load Transfer Analysis in Short Carbon Fibers with Radially-Aligned Carbon Nanotubes Embedded in a Polymer Matrix

Abstract

A novel shortfiber composite in which the microscopic advanced fiber reinforcements are coated with radially aligned carbon nanotubes (CNTs) is analyzed in this study. A shear-lag model is developed to analyze the load transferred to such coated fibers from the aligned-CNT reinforced matrix in a hybrid composite application. It is found that if the carbon fibers are coated with radially aligned CNTs, then the axial load transferred to the fiber is reduced due to stiffening of the matrix by the CNTs. Importantly, it is shown that at low loading of CNTs in the polymer matrix, there is a significant reduction in the maximum interfacial shear stress, e.g., at 1% CNTs, there is an ~25 % reduction in this maximum stress. Further, the modification in the load sharing between the fiber and the matrix plateaus at ~2% CNT matrix loading, indicating a small but critical window for engineering the interface in this manner. Effects of the variation of the aspect ratio of the fiber, CNT volume fraction and the application of radial load on the load transferred to such CNT coated fibers are also investigated.