View article

A non-intrusive torsional vibration method for monitoring and tracking small changes in crack growth of shafts is presented in this paper. This method resolves and tracks characteristic changes in the natural torsional vibration frequencies that are associated with shaft crack propagation. While this technique is being applied to reactor coolant pumps (RCPs) it is generally applicable to any type of rotating equipment, including drivelines, and can be applied to detecting and tracking changes in blade natural frequencies in gas or steam turbines. This technique was first developed on a laboratory scale rotor test bed to investigate shaft cracking detection techniques under controlled conditions. The test bed provided a mechanism to evaluate sensing technologies and algorithm development. For accurate knowledge of the crack characteristics (crack depth and front), a shaft was seeded with a crack which was then …