Experimental and numerical investigations on fretting fatigue in a bridge-flat component using a stress life prediction model

The study investigated the fretting fatigue behavior of a bridge-flat component, utilizing a flat specimen with two bridge-type pads tested under cyclic loading. Numerical simulations were also carried out using the finite element method. Firstly, precise calculations of contact stress were performed with the material's elastoplastic model. Secondly, the stress distribution on the maximum stress cross-section was extracted, and the stress gradient was computed. Finally, a stress fatigue life prediction model considering the stress gradient was proposed, and the predicted life was compared with the test life. The results of the study revealed that the specimens exhibited high stress gradients at the edges of the contact region during the bridge-flat tests. In comparison with plain fatigue, fretting fatigue life was significantly reduced. The life prediction model proposed in this paper demonstrated good accuracy for predicting fretting fatigue. A novel stress-fatigue life prediction model for fretting fatigue was proposed. Parameters in the new model are easy to obtain with FEM and have good physical significance. A new stress gradient and critical distance calculation method was proposed. The performance of the new model shows good accuracy.