Optics: measuring and testing – Material strain analysis
Patent
1986-10-14
1988-02-02
LaRoche, Eugene R.
Optics: measuring and testing
Material strain analysis
356374, 250231R, 250237G, 73800, G01B 1114
Patent
active
047226005
ABSTRACT:
Two electro-moire systems provide strain values directly. By shifting a reference grating relative to a specimen grating along the direction perpendicular to the grating line the resulting moire fringes sweep across the field. In one method two photo-detectors are used to record the cyclic intensity signals. The phase difference between the two signals is used in a special formula for the calculation of strain. In the other method only one photo-detector is used, and the frequency information of the cyclic signal is used in another formula for the calculation of strain. The electrical signals from photo-detectors are converted into digital signals and processed using a digital computer through FFT (Fast Fourier Transformer) to eliminate noise. Strain-values as small as one microstrain can be measured.
REFERENCES:
patent: 3768911 (1973-10-01), Erickson
patent: 4014613 (1977-03-01), Sharp, Jr. et al.
patent: 4050818 (1977-09-01), Sharp, Jr. et al.
patent: 4051483 (1977-09-01), Suzuki
patent: 4079252 (1978-03-01), Brake
patent: 4127109 (1978-11-01), Fourney et al.
patent: 4525858 (1985-06-01), Cline et al.
patent: 4560280 (1985-12-01), Iwamoto et al.
patent: 4678948 (1987-07-01), Schmitt
patent: 4684257 (1987-08-01), Hanaoka et al.
Chiang, F. "Moire Methods of Strain Analysis" SESA's Manual on Experimental Stress Analysis, Third Edition, Ch. 6, Mar. 1978.
LaRoche Eugene R.
Mis David
Teltscher Erwin S.
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