Fatigue Strength of Structural Elements with Cracks Repaired by Welding

摘要

Weld repair is commonly used to improve, update, and rework parts and structural elements. The results of experimental investigation of the fatigue life of structural elements containing fatigue cracks repaired by welding are considered in this document. Two types of repairs were considered. In the first case, the welding was applied for repair of fatigue cracks in base metal (not welded). The fatigue cracks in large-scale specimens of base metal were repaired by welding and subjected to further fatigue testing. In the second part of experimental studies, the efficiency of weld repair of welded elements containing fatigue cracks originated at the weld toe was considered including the second and third repair of welded specimens with subsequent fatigue testing of large-scale specimens. In both studies of weld repair of fatigue cracks in base metal and in welded elements the efficiency of the application of the Ultrasonic Peening (UP) for fatigue improvement of repaired by welding structural elements was investigated. Examples of industrial applications of weld repair of fatigue damaged elements including application of UP for fatigue improvement are also considered.