Fatigue Life Improvement by Reducing Welding Residual Stress with Local Heating for Steel Bridge Members

초록

This study investigated the possibility of fatigue life improvement by reducing the weld residual stress with local heating for the steel bridge member. A crossing welded part of longitudinal and transverse stiffeners of a steel plate deck was chosen as the target of this study because it is one of the parts prone to fatigue damage in steel bridge structures. To reduce weld residual stresses and improve the fatigue life of this part, the authors applied a local heating method using a highfrequency induction heating (i.e., IH) device. The welded part was heated up to 250°C for 9 seconds and 550°C for 30 seconds. This quick and local heating provided the newly generated compressive stress to the welding tensile stress originally existed. Eventually, the tensile residual stress around 200 N/mm2 near the weld toe was reduced to less than -30 N/mm2. The reduction effect of weld residual stress by local heating on the fatigue life was examined through the experimental 1pproach. The locally heated group had higher durability than that of the non-locally heated group in certain stress ranges. © The Author(s), 2024.

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