Turbine blade fatigue monitor.

摘要

An on-line vibratory fatigue monitor measures displacement of an object such as the blade of a turbine rotor to generate a displacement signal produced by proximity sensors and calculates accumulated fatigue in the object in dependence upon the displacement signal. The signals are digitized and processed, by taking a Hilbert transform, to detect the amplitude envelope and instantaneous frequency of the displacement. The amplitude and frequency are combined with steady state stress on the object to determine fatigue usage which is accumulated by constantly monitoring vibratory displacement and changes in the steady state stress.