Accession Number : ADA305084

Title :   An Assessment of the Accuracy of Orthotropic Photoelasticity.

Descriptive Note : Contractor rept.,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG

Personal Author(s) : Hyder, M. W. ; Liu, D. H.

PDF Url : ADA305084

Report Date : MAR 1984

Pagination or Media Count : 257

Abstract : A study is described which had as its goal the determination of the accuracy of orthotropic photoelasticity. The study consisted of both theoretical and experimental phases in the theoretical phase a stress optic law was developed. The stress optic law included the effects of residual birefringence in the relation between applied stress and the material's optical response. The experimental phase had several portions. First, it was shown that four point bending tests and the concept of an optical neutral axis could be conveniently used to calibrate the stress optic behavior of the material. Second, the actual optical response or an orthotropic dish in diametral compression was compared with theoretical predictions. Third, the stresses in the dish were determined from the observed optical response, the stress optic law, and a finite difference form of the plane stress equilibrium equations. It was concluded that orthotropic photoelasticity is not as accurate as isotropic photoelasticity. This is believed to be due to the lack of good fringe resolution and the low sensitivity of most orthotropic photoelastic materials.

Descriptors :   *FIBER REINFORCED COMPOSITES, *PHOTOELASTICITY, PREDICTIONS, THEORY, ELASTIC PROPERTIES, TEST METHODS, ACCURACY, BENDING, SENSITIVITY, FINITE DIFFERENCE THEORY, RESIDUAL STRESS, BIREFRINGENCE, PLANE WAVES, LOW RESOLUTION, COMPLEX VARIABLES, PARABOLIC ANTENNAS.

Subject Categories : Mechanics
      Laminates and Composite Materials
      Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE