FOURIER-TRANSFORM FRINGE ANALYSIS OF ELECTRONIC SPECKLE PATTERN INTERFEROMETRY FRINGES FROM HIGH-SPEED ROTATING COMPONENTS

The ability to measure in-plane displacement on the surface of a rotating structure under service conditions and real-time analysis to provide component strain distributions would form the ideal experimental optical technique. Pulsed laser electronic speckle pattern interferometry, which can display interference patterns for in-plane displacement in conjunction with the Fourier transform method of fringe analysis, is one attractive approach that is coming closer to this ideal. The optical system used enables a wide range of rotational speeds to be covered with tangential velocities up to 300 m/s.