Fracture of a galvanized steel U-bolt stirrup of an overhead electrical transport line

The analysis carried out allows concluding that the failure of the component took place by fatigue. Fracture was initiated at the 1st/2nd thread of the component, close to the screw joint. The variable load acted perpendicularly to the plane of symmetry of the component. Corrosion took place simultaneously with fatigue crack propagation speeding the failure process. The inclusions present in the steel, mainly those that intercept the component surface, as well as the surface notches due to hot rolling, enhanced the disclosure of the fatigue process leading to premature failure of the component.