Pullout Response of a Smooth Fiber with an End Anchorage

The main objective of this study is to develop an analytical model to predict the pullout load versus end slip relationship of a smooth fiber having an end anchorage embedded in a matrix. The resisting pullout load of the fiber is composed of a component due to interfacial bond at the fiber-matrix interface and a component due to mechanical anchorage at the embedded end of the fiber. The concept of a relationship between the bond shear stress and the slip at the fiber-matrix interface is used to obtain the force component due to the interfacial bond. To account for the mechanical anchorage resistance at the embedded end, a spring component at the embedded end of the fiber is used. The constitutive property of the spring is assumed to be nonlinear. Based on these concepts and assumptions, a set of analytical solutions to predict the pullout load vesus end slip relationship is derived and then solved by an iterative procedure. Examples predicting the pullout load versus slip curve of a smooth fiber with and without mechanical anchorage at the embedded end are shown and compared. Different modeling aspects of the fiber end anchorage effect and its influence on the pullout load versus slip response are investigated and discussed, with particular emphasis on the tensile force and the bond shear stress distribution along the fiber-matrix interface.