Date of Award
Master of Science (MS)
This study describes a method to evaluate the fatigue life of a welded joint of a snowplow. Fatigue specimens were then fabricated, which simulated the joint and its loading characteristics. The joint in the specimens were characterized by measuring the geometry of the weld and the hardness of the parent material, weld material, and heat affected zone. It was determined that the fatigue crack that developed in the joint was exposed to mode I fracture forces in the normal plane of the crack. The specimens were then tested in a hydraulic closed looped system to determine the mechanism of fatigue for the welded joint and the fatigue crack propagation parameters. A finite element model was then generated with a pre-crack mesh in a location determined from the experimental and field data on crack growth. The crack parameters were estimated from examining the test specimens after the test was completed. The FEA results were then compared to the experimentally determined stress intensity factors.