Abstract
Fatigue cracks often initiate and propagate from fillet weld toe. The impact crack closure retrofit treatment, or ICR treatment, was applied to fatigue cracks at weld toes of fillet welded ribs to see the effectiveness of the technique to 300mm long fillet welds. The ICR treatment is the technique to use air impact tool to produce plastic deformation near the fatigue cracks to close crack surface not to open with service loading. First, specimens of fillet welds were partially treated by the ICR treatment, to control fatigue cracks in length at surface. Then, fatigue cracks were further treated by the ICR treatment in order to stop or to reduce further fatigue crack propagation. For the crack initiated and propagated to about 24mm long along the fillet weld toe, the remaining fatigue life was significantly improved by ICR treatment.
