Intensity of singular stress fields of an embedded fibre under pull-out force

Abstract

Previous experimental studies of fibre pull-out test show two dangerous points on the interface. Failure usually occurs at the bonded end of the fibre (Point A) or at the entry point on the surface of the matrix (Point E). Both points have different singular stress fields which causes crack initiation, crack propagation, and final failure. In this paper, intensity of singular stress fields (ISSF) at the fibre bonded end A and ISSF at the intersection point E of the fibre and the surface are discussed. The analysis method focuses on calculating the finite element method (FEM) stress radio by using a reference model and an unknown model. In the unknown model and the reference model, same FEM mesh pattern is applied. To analyse the ISSF at A, the body force method solution is used as the reference model. To analyse the ISSF at E, the reciprocal work contour integral method (RWCIM) solution is used as the reference model. Then, the two ISSFs are compared and discussed by varying the fibre embedded length lin. When lin is shorter, the singular stress at A is larger than the singular stress at E. When lin is longer, the singular stress at E is larger than the ISSF at A.