Dispersion of Guided Circumferential Waves in a Circular Annulus
Fatigue cracks have been found to initiate and grow in the radial direction in many of the annulus shaped components in aging helicopters. Those include some of the most critical components such as the rotor hub, connecting links and pitch shaft, etc. At the present time, detection of such radial fatigue cracks relies mostly on visual inspection. A more systematic, automated, and efficient method to detect these cracks must be developed.