Predicting the Fatigue Life of a Ball Joint

Abstract The technical conditions and service life of steering elements of vehicles are an important factor directly affecting road safety. Therefore, high reliability of such kind’s components is required. In the paper, on the basis of the stand test, the fatigue durability of a ball joint of a steering tie rod is determined. It is elaborated together with a prediction for the further number of cycles, enabling to determine the technical state of the tested component containing its service life. The aim of the article is to select an appropriate mathematical model with respect to describing the relationship between the moment of force and the fatigue cycles performed for the ball joint of a steering rod of a vehicle with a GVW above 3.5 tonnes, and identifying the model’s parameters. As a result, the limit number of loading cycles after which the examined joint does not meet safety requirements is estimated.