Abstract
In estimating fatigue resistance of existing steel bridges, applied stresses are not always perpendicular to weld toes. Fatigue tests of non-load-carrying fillet welded joints with inclined ribs are carried out. The ribs are inclined at 0, 15 and 30 degrees to perpendicular direction of applied stress. Fatigue cracks for the specimens with inclined angle of 0 degree are initiated at multiple points along the fillet weld toes, and then coalesce with adjacent cracks to propagate in a same plane. On the other hand, numerous fatigue cracks are initiated along the weld toes and propagated in different planes for the specimens with inclined angle of 15 or 30 degree. This fatigue crack propagation pattern yields increase in fatigue life as the inclined angle increases. The test results show that the normal stress perpendicular to fillet weld can be used for estimating fatigue life of inclined non-load-carrying fillet welded joints.
