Detection of a natural fault in ball bearings during endurance tests by optical fibre sensors


Rolling element bearings (REBs) are basic machine parts in rotating machinery. A defect in the REB can lead to a critical failure of the system. One of the common methods for monitoring the health of REBs is through vibrations analysis. This study examines a new method for monitoring rotating dynamic systems. In the new method, rather than measuring global vibrations, monitoring is performed by recording the local strains using optical Fiber Bragg Grating (FBG) sensors. Previous studies have shown that FBG sensors can not only detect artificially implanted defects in REBs, but their readings can be also processed to determine the defect size and severity. In the current study, several endurance tests were conducted. The goal of these tests was to identify and monitor the initiation and propagation of natural defects in the REBs. Using FBG sensors, it was possible to monitor the severity of the defect in the bearings and estimating the defect size at different stages of the experiment.