Patent ID: 6055053
Filing Date: 2000-04-25
Classification: G01L

Abstract:
A method for determining shear stresses in a structure comprising the steps of:coating a structural specimen with a photoelastic material;loading the structural specimen to produce no more than one-half of a wavelength of birefringence in the photoelastic material;illuminating with elliptically polarized light the structural specimen coated with the photoelastic material to cause a multiplicity of discrete areas on the structure to reflect elliptically polarized light;creating an electronic image of a portion of the structural specimen including the multiplicity of discrete areas;analyzing the elliptically polarized light reflected from the multiplicity of discrete areas of the illuminated specimen to determine the orientation and magnitude of major and minor axes of the elliptically polarized light reflected from each of said multiplicity of specimen areas; andprocessing the orientation and magnitude of major and minor axes of the elliptically polarized light for each analyzed area to produce a result indicative of shear stress magnitude and direction in the specimen at each discrete area.