Resonant Ultrasound Inspection of Ceramic Ball Bearings

Quatro proposes to apply the recently invented Resonant Ultrasound Spectroscopy (RUS) technology to the problem of non-destructive inspection (NDI) of rocket engine ceramic ball bearings. We have previously demonstrated that the RUS technology can quickly (seconds) detect the presence of flaws such as cracks, occlusions, density variations, roundness errors, texturing and internal strain in ball bearings which are not readily detectable with normal testing procedures. In this phase I effort, we will extend our recently developed analysis tools for prediction of the RUS spectrum of asymmetric or anisotropic ball bearings to compute the spectral perturbations by small flaws that could lead to failure. These spectra when compared to the measured spectrum will provide a quick screen for flaw type. For every bearing, a spectral history can be maintained, and during routine maintenance testing, bearings that have developed wear induced flaws can be quickly identified through comparison to prior measured spectra and the computed library of flawed spectra. The proposal will outline our approach to the problem of extending the current analytical techniques coupled with the spectral measurements to produce a software tool that can image the flaw producing the ultrasound spectrum.