Abstract
The weld repair requires no additional member such as splice plates, therefore it will be more cost efficient and shorten the work period comparing with the conventional bolted repair method. However, the weld repair has possibility to introduce weld defects or residual deformation which may reduce the fatigue strength of the repaired joints. Besides, even though fatigue cracked joints are restored to the initial condition with sound weld repairs, the fatigue crack will reoccur in the repaired joint, because the fatigue strength of cracked joints is low in most of the cases. In this study, a new welding material named low temperature transformation (LTT) welding material, which enables to introduce compressive residual stress in the vicinity of the weld bead and reduce weld deformation, was applied to the weld repair. The applicability of the LTT welding material to the weld repair was investigated by the fatigue tests with compact tension specimens and a steel girder specimen.
