Stress Evaluation In High Speed, Rotating Machinery With The Lcr Ultrasonic Technique.

Abstract

The LcR ultrasonic technique is ideally suited for stress measurement, since it is a bulk longitudinal wave that propagates just underneath the surface of the item being inspected. Additionally, it is most sensitive to stress, and least sensitive to material texture. A description of the LcR probe is included, and brief summaries are furnished of successful applications of the technique to stress evaluation in a turbine disk and a generator retaining ring. Additional discussion is given on an application to a compressor rotor that was found to be bowed. The measurements on the compressor rotor were conducted in an industrial shop, using readily available equipment. Only the probe was specially designed for the work. Discussions of other possible applications also are given.