A new theoretical model of the quasistatic single-fiber pull-out problem: A rate-dependent interfacial bond strength

Abstract

An extended analysis for the single-fiber pull-out process is presented based on Part I of this paper (Qing, 2013). The whole process of fiber pull-out contains three stages: elastic deformation with fully bonded interface, partially debonded interface and fully debonded interface with frictional sliding. Stress required to debond the fiber-matrix interface and pull-out a fiber is expressed as a function of the model length, fiber volume content and the radial residual thermal stress. The influence of fiber pull-out rate on interfacial frictional coefficient and shear strength is also taken into account. The calculation results show that the initial debonding stress is independent on the radial residual thermal stress, decreases with the increase of the pull-out rate, while increases and reaches a plateau with the increase of model length. The applied stress to cause further debonding increases with the increase of the radial residual thermal stress, while decrease with the increase of fiber pull-out rate. There is a drop for the applied stress and displacement of fiber end when the interface debonds to further close to the model length.