Three-dimensional analysis of the interaction between a matrix crack and nanofiber

A three-dimensional study of interactions between a matrix crack and nanofibers is undertaken. The nanofibers considered in the study have a hollow structure and a certain wall thickness. The analytical study is performed by considering a penny-shaped crack propagating towards a pair of nanofibers placed symmetrically with respect to the crack. The three-dimensional study accounts for the influence of nanofiber hollow geometry and outer diameter on crack energetics. The effect of the mismatch between the elastic properties of nanofiber and matrix is also considered. Finally, the influence of the interphase between nanofiber and matrix on crack energetics is investigated. Energy release rates along the crack front of the penny-shaped crack are computed to understand the nature of the toughening effect of nanofibers. The results of the study indicate a significant influence of nanofiber wall thickness and longitudinal modulus on crack energetics. Also, the presence of an interphase between a nanofiber and matrix seems to alter the crack energetics considerably. Finally, the results of the study indicate that nanofiber diameter may have a positive or negative effect on resistance to crack propagation depending on nanofiber wall thickness. (C) 2009 Elsevier Ltd. All rights reserved.