Estimation of the Structural Reliability for Fatigue of Welded Bridge Details Using Advanced Resistance Models

This present paper concerns the application of probabilistic fatigue life prediction models based on S–N curves aiming at the estimation of the safety level for a non-load carrying cruciform joint. The safety level is expressed in terms of the reliability index as a function of the number of applied cycles. Estimating the reliability of a structural component against fatigue failure is relevant for both new and existing structures. The analysis is executed considering three models. For each of them, the input random variables are given in a probabilistic manner, based on fatigue test data from the scientific literature. The effect of the model uncertainty on the model response is quantified for both the load and the resistance side, demonstrating its relevance. Moreover, it has been shown that a 0.5 to 1 increase in the reliability index is achievable by applying the newly proposed, more complex model.