Assistive Bonding Assisted Prevention of Weld Root Fatigue Cracks

Abstract

Extending the service life of structures and decreasing the damage caused by fractures or deterioration are important. Previous studies have confirmed that adhesive-bonding-assisted-fillet-welding in cover plate joints has a positive impact on stress mitigation near weld roots and also presents a possibility for improving fatigue life. To investigate the effects of fillet welding combined with adhesive bonding on the fatigue life of weld roots in steel bridge members, several experiments were performed on the specimens, modelling the welds between the flange and the sole plate. The possibility of defect occurrence was reduced by inserting a heat-resistant rubber into the edge of the adhesive bond part of the specimen. A cyclic tensile stress was applied to the weld root of the specimen to generate fatigue cracks from the weld root. Compared with the only-weld specimens, the specimens with welding and bonding demonstrated evident stress mitigation and extension of fatigue life. In addition, the incomplete filling of the bond could possibly reduce the effect of fatigue life improvement.