Accession Number : AD0717324

Title :   Extension of Survival Range for Diffraction Grating Strain Gages.

Descriptive Note : Technical rept.,

Corporate Author : NORTH CAROLINA STATE UNIV RALEIGH

Personal Author(s) : Steele,Robert S. ; Douglas,Robert A. ; Stadelmaier,Hans. H.

Report Date : OCT 1970

Pagination or Media Count : 30

Abstract : Diffraction grating strain gages cease to function when the surface is so roughened with strain that the gages no longer respond as coherent diffraction sources. A method is described by which the range of strains over which gages may be used, is extended significantly. This method requires incident radiation in a grazing - parallel attitude rather than the attitude normally employed in studying diffraction. A new diffraction equation is derived as are the equations which are necessary to calculate strain from an experimental configuration. The required changes to an existing test facility are discussed. Results obtained using this modified system demonstrate the improved range of the diffraction strain gage under dynamic straining. (Author)

Descriptors :   (*DIFFRACTION GRATINGS, STRAIN GAGES), (*STRAIN GAGES, LIFE EXPECTANCY), STRAIN(MECHANICS), DIFFRACTION, OPTICAL ANALYSIS, DESIGN, TEST METHODS, MONOCHROMATIC LIGHT, MATHEMATICAL ANALYSIS, RODS

Subject Categories : Test Facilities, Equipment and Methods
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE