Study on the Fatigue of a Spherical Bearing Under Different Loading Conditions Considering Rotation Effect

In order to study the fatigue life of a large spherical bearing under actual working conditions, the finite element software ABAQUS was firstly used to establish the spherical bearing model and simulate the mechanical properties of the bearing at different rotation angles under four working conditions of pressure, tension, pressure shear, and tension shear. And the stress characteristics under the corresponding working conditions were obtained. On this basis, the stress results were imported into the fatigue analysis software, and the fatigue life of each component of the spherical bearing was calculated under the four working conditions. The results show that: the rotation angle of the upper bearing plate has obvious influence on the maximum stress of the bearing under various working conditions. The maximum stress is 554.5 MPa and locates in the wedge-shaped region of the lower bearing plate under the working condition of the joint action of tension and X-direction shear force, and when the rotation angle of the upper bearing plate is 1°. In other working conditions, the maximum stress of the bearing mostly occurs in the wedge-shaped position of the upper and lower bearing plates. The influence of the rotation angle of the upper bearing plate on the minimum fatigue life of the bearing shows the same trend as the influence on the maximum stress. The minimum fatigue life is 13,000 times and locates in the wedge-shaped region of the lower bearing plate under the working condition of the joint action of tension and X-direction shear force, and when the rotation angle of the upper bearing plate is 1°. In other working conditions, the lowest fatigue life of the bearing is also mostly found in the wedge-shaped area of the upper and lower bearing plates. So, the wedge-shaped area should be strengthened in the design.