Fatigue life evaluation by weight functions for orthotropic bridge decks

This paper is concerned with the prediction of fatigue crack propagation in welded orthotropic decks for road and railway steel bridges. The analysis makes use of a weight function (WF), that provides effective evaluation of the stress intensity factor (SIF) for any crack length and loading condition. The WF was determined by a hybrid (numerical/analytical) technique and verified with numerical results. The fatigue life were estimated for different initial crack lengths and loading cycles. Endurance limits were obtained to establish in-service inspection schedule of the structure. The effect of weldment residual stress on the fatigue life was also analyzed. It was shown that the WF technique provides an expedient evaluation of these effects, also accounting for non-linear (contact) phenomena.