Evaluation of Stress Intensity Factor Range in the Prediction of Fatigue Crack Growth at Rib-to-Deck Welded Joints of Orthotropic Steel Decks

摘要

This paper studies the evaluation of the proper stress intensity factor ranges in the fracture mechanics-based fatigue analysis of the rib-to-deck welded joints of orthotropic steel decks. It is pointed out in the paper that the stress intensity factor ranges used in Paris law for the fatigue crack growth at a rib-to-deck welded joint can not be taken as a value proportional to the corresponding stress ranges since the compressive stresses are the dominant transverse stresses in the cyclic stresses under the action of truck traffics. The proper fatigue design loads to characterize the standard truck loading for the accurate calculation of the tensile transverse stresses at the rib-to-deck joints is also discussed in the paper. It is shown that the loads from two neighboring wheel-axles of heavy trucks have to be taken into account.