Interfacial stress transfer behavior in a specially-shaped fiber/matrix pullout test

Specially designed fibers are widely used in engineering practice because the specially-designed shape can help to improve the bonding strength of the fiber and the interface.Studied in this paper is the interfacial shear stress transfer behavior on both sides of the specially designed fiber when it is being pulled out;in which automatic analysis of three-dimensional photoelasticity is employed and the finite element method is adopted.The results show that the stress transfer occurs mainly in the region near the fiber’s embedded end where the stress reaches its critical point,leading to debonding of the interface.Before debonding,as the pullout loading increases,the peak value of shear stress transfers along the fiber from the embedded end to the interior of the matrix,and then stops at the hooked part of the fiber because of its impediment.When the interface begins to debond as the load increases,the shear stress can be transferred to the hooked part.