Document Type

Patent

Abstract

A method for optically determining the ratio of Poisson's ratio to modulus of elasticity for optically isotropic and optically anisotropic transparent materials and then for determining the stress-optical constants for such materials. A collimated monochromatic light beam is directed at the tip of a crack in a loaded thin plate specimen of the material and the diameters of the resulting transmitted and reflected caustics are measured at points equidistant from the specimen. The light beam also is directed to an uncracked region in a loaded thin plate specimen of the material and the number of displaced fringe reflected on a screen are counted for a predetermined change in loading. The ratio of Poisson's ratio to modulus of elasticity and the stress-optical constants are determined from the thickness of the specimen, the displaced fringe count, the wavelength of the light beam and the ratio of the caustic diameters.

Patent Country

US

Patent Number

US4195929

Publication Date

4-1-1980

Assignee(s)

The University of Toledo

Application Number

05/948317

Filing Date

October 1978

Primary Class

356/32

Secondary Class

73/800

Rights

These materials are free of copyright restrictions and are in the public domain within the United States only. The USPTO reserves the right to assert copyright protection internationally.

Institution

The University of Toledo

Repository

University of Toledo Libraries

Digital Publisher

Digital Initiatives

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