METHODS OF ANALYSING APPARATUS

摘要

Engine health monitoring is used to assess the health of an engine, such as a gas turbine engine. Blades mounted on a shaft produce a modal response when excited. The shaft has an order related component that varies with the rotational velocity of the shaft. Modal responses are increased when the natural frequency range of the selected blade mode intersects with one of the order related components. By applying a short time chirp-Fourier transform with a frequency speed that is a function of a rate of change in the rotational velocity of the shaft a selected signal can be isolated. Cracks in the blades can be detected from the isolated signal.

主权项

1. A method for determining an artifact in a component comprising the steps:
a) exciting the component to induce a resonance response; b) calculating the real and imaginary components of bi-coherence b of a resonance response at pk0 and qk0 wherein p and q are integers and k0 is the component resonant frequency; and c) determining a location of a point related to calculated components in real and imaginary two-dimensional space, the location of the point determining the presence of an artifact.