Fatigue Fracture Mechanism of Rod End Body of Rod End Joint Bearing

The rod end body of a rod end joint bearing fractured under tensile and compression loads. The fatigue fracture mechanism was analyzed by the observation of fracture morphology and microstructure and the measurement of micro area composition and hardness. The results show that the fatigue fracture of the rod end body occurred in the transition area between the rod and ring (position A) and on the ring in 45° direction to the rod (position B). Serious fretting wear existed between the ring inner face of the rod end body and the outer ring outer face of the joint bearing, resulting in the initiation of cracks. Under the tensile and compression loads, the microcracks at position B first propagated, leading to the fracture. The fracture at position B changed the force direction at position A, leading to the inclination of the rod end body. The inclination resulted in the cracking at position A, and finally led to the fracture of rod end body.