Interaction between a nanofiber and an arbitrarily oriented crack

摘要

The interaction between a hollow cylindrical nanofiber and a crack in an infinite medium is investigated. The two-dimensional problem, when the crack lies in the cross-sectional plane of the fiber, is solved for a transversely isotropic fiber in an isotropic matrix phase. The reported work to date on crack-fiber interaction problems seems to be based on a conventional solid fiber cross-section, whereas in this study, a hollow fiber cross-section is considered. The crack is considered at various orientations with respect to the nanofiber. Mismatch between Young's modulus and Poisson's ratios of the fiber and matrix, fiber diameter, and fiber wall thickness, are some of the parameters in the study. Finite element method is used as the analysis tool to compute energy release rates in mixed mode conditions. Fiber-matrix interface tractions are also computed to investigate secondary failure mechanism. The behavior of a hollow nanofiber is shown to be significantly different from that of a fiber with a solid cross-section. However, with increasing nanofiber wall thickness the results of the present investigation are seen to converge to the solutions of a solid fiber. Finally, the influence of the properties of the interphase region between the hollow nanofiber and matrix on energy release rates is investigated.