Welding is widely used for construction of many structures. Residual stress is generated near the bead because of locally given heat. Tensile residual stress degrades fatigue strength. The authors propose a new method for reduction of tensile residual stress in which ultrasonic vibration is applied during welding. First, transmission of ultrasonic vibration is examined. Second, reduction of residual stress using ultrasonic vibration is examined. It is concluded that ultrasonic vibration is transmitted to specimen well and residual stress is reduced using ultrasonic vibration.
