ENVIRONMENTALLY-ASSISTED FATIGUE CRACK GROWTH IN PRESTRESSING STEEL WIRES

摘要

This paper presents the evolution of the surface crack front in prestressing reinforced concrete steel wires subjected to fatigue in air and to corrosion-fatigue in Ca(OH)_2+NaCl. To this end, a numerical modelling was made on the basis of a discretization of the crack front (with elliptical shape), considering that the crack advance at each point is perpendicular to such a front according to a Paris-Erdogan law, and using a three-parameter solution for stress intensity factor (SIF). Each analyzed case (a particular initial crack geometry) was characterized by the evolution of the semielliptical crack aspect ratio (relation between the semiaxes of the ellipse) with the relative crack depth and by the variation of the maximum dimensionless SIF at the crack front.