Accession Number : AD0702420

Title :   INVESTIGATION OF APPLYING INTERFEROMETRIC HOLOGRAPHY TO TURBINE BLADE STRESS ANALYSIS.

Descriptive Note : Final rept. 29 Jan 69-29 Jan 70,

Corporate Author : UNITED AIRCRAFT CORP EAST HARTFORD CONN RESEARCH LABS

Personal Author(s) : Waters,J. P. ; Aas,H. G. ; Erf,R. K.

Report Date : FEB 1970

Pagination or Media Count : 111

Abstract : The primary results of a research investigation to determine the feasibility of applying interferometric holography to turbine blade stress analysis are reported and may be briefly summarized as follows: (1) It has been demonstrated that the strain at the surface of a turbine blade, excited in dynamic flexure, can be calculated from interferometric holographic fringe information. (2) Interferometric holography appears to offer some promise in the detection of weaknesses, unusual wear or fatigue in turbine blades, however experimental implementation and fringe interpretation would be a somewhat time consuming process. (3) The introduction of elevated temperatures to the turbine blade stress analysis problem requires the use of pulsed holographic techniques for best results, but otherwise it appears to present no insurmountable problems. (4) Pulsed interferometric holograms of transient and cyclically excited turbine blades have been successfully and readily constructed, demonstrating that the developed pulsed laser system possesses more than sufficient pulse reproducibility, coherence and intensity for recording reflected light holograms. (Author)

Descriptors :   (*TURBINE BLADES, NONDESTRUCTIVE TESTING), (*STEREOPHOTOGRAPHY, *INTERFEROMETERS), LASERS, STRESSES, STRAIN(MECHANICS), OPTICAL ANALYSIS

Subject Categories : Holography
      Test Facilities, Equipment and Methods
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE