Abstract
Welding is widely used for construction of many structures. It is well known that residual stress is generated near the bead because of locally given heat. Tensile residual stress on the surface degrades fatigue strength. On the other hand, welding is used for repair of mold and die. In this case, reduction of residual stress is required because of protection from crack of welded part in mold and die. In this paper, a new method for reduction of residual stress of welded joint is proposed for repair welding of mold and die. In this method, low frequency and ultrasonic vibrations are used during welding. Thick plates are used as specimens of mold and die. Residual stresses are reduced when low frequency and ultrasonic vibrations are used during welding. Experimental results are examined by simulation method using an analytical model. One mass model considering plastic deformation is used as an analytical model. Experimental results are demonstrated by simulation method.
