A probabilistic study of the fatigue behaviour of improved tubular bridge joints

This paper presents the results of several probabilistic linear elastic fracture mechanics (LEFM) calculations conducted to study the fatigue behaviour of tubular bridge joints with and without post weld treatment. The effect of post weld treatment is considered through the calculation of an effective stress intensity factor which takes into account the presence of residual stresses (due to welding and post weld treatment) along the crack path. The results of large-scale fatigue tests on tubular bridge truss specimens are predicted using this approach. Specifically, the observed shift of the critical crack initiation site after post weld treatment is predicted.