A study of interfacial property of composite based on the shear stress criterion with cyclic loading process

It is well known that the efficiency of load transfer across the interface plays a significant role on the mechanical behavior of fiber-reinforced composites. Several experimental tests have been designed to measure the interfacial properties of composite, one of which, i.e., single fiber pullout test has been widely used to measure the interfacial strength and friction stress. The purpose of the present study is to extend the application of the single-fiber pullout test in evaluating the interfacial properties. Theoretical analysis is presented for the single-fiber pullout during unloading and reloading process based on the shear stress debonding criterion and the modified analysis of stress. The axial stress of fiber is presented during unloading and reloading process. The applied stress is represented as functions of reverse friction length "u", residual reverse friction length "r" during the unloading-reloading process. The influence of fiber pullout rate on interfacial frictional coefficient is also taken into consideration.