Experiment and Analysis of Influence of Ultrasonic Peening on Fatigue Life in Pad Welded Joint

Effects of ultrasonic peening on fatigue life of pad welded joint were analyzed by fatigue life analysis method by RPG load. It's noted that the ultrasonic peening is one of the most effective method for improving fatigue life of welded joint. Ultrasonic Impact Treatment, UIT, was adopted in this study as the ultrasonic peening method. A significant increase in fatigue life was observed on the pad welded joint with UIT treated weld toe. The improvement was estimated mainly due to compressive residual stress introducing, stress concentration reducing and grain refining in weld toe area. Estimated fatigue life by FLARP was consistent with experimental result.