Application of the probabilistic mechanics of fatigue fracture to the evaluation of the reliability of welded structures

We propose a method for the evaluation of the reliability of load-carrying. elements of welded metallic bridges in the process of long-term operation based on the probabilistic mechanics of fatigue fracture. This method enables one to estimate the risk of failure of a structure as a result of the development of fatigue cracks in the zones of stress concentration near the welds with regard for the irregularity of in-service loads and stochastic distributions of the sizes of initial technological defects in welded joints. By using the proposed method, we study the possibilities of elevation of reliability as a result of the detection of the most dangerous defects in the course of periodic defectoscopic monitoring of the structure. Some examples of numerical computations are presented.