FATIGUE IMPROVEMENT OF WELD REPAIRED CRANE RUNWAY GIRDER BY ULTRASONIC IMPACT TREATMENT

摘要

The fatigue improvement method using ultrasonic impact treatment was examined. This method was applied to in-plane-gusset detail and out-of-plane gusset detail of existing crane runway girders. Comparison with other fatigue improvement methods was based on fatigue tests performed on small-scale welded specimens, and UIT gave the best result. Also, applicability to mild steel and the influence of repair welds was examined through girder fatigue tests. Fatigue improvement was obtained for 400 MPa class mild steel, even after repair welding.