Fatigue life prediction of flexible bearings based on ABAQUS and nCode-DesignLife

Abstract

Flexible bearings are critical components of harmonic drives. In service, the corresponding positions of the long and short axes of the inner and outer rings of a flexible bearing regularly change. This leads to a fatigue fracture of the outer ring because of the cyclic alternating load. In this study, a multi-body contact model and a dynamic model were established using ABAQUS to analyze the load spectrum of a flexible bearing and a wave generator. The dynamic analysis results were employed to simulate the fatigue life of the inner and outer rings using nCode-DesignLife. The results show that the inner ring underwent significant fatigue damage at the long-axis position, and the corresponding fatigue life was low. As the damage on the outer ring was due to continuous alternating deformation, the inner and outer surfaces of the outer ring were significantly damaged. Besides, the outer ring underwent fatigue damage prior to the inner ring under the same working conditions. The results provide theoretical references and practical guidance for the design and life estimation of flexible thin-wall bearings.