Abstract
It is known that birefringent coatings are a powerful experimental technique for the determination of surface strains of metals or other opaque bodies. In this paper the complete state of strain in such a coating is determined for an arbitrary one-dimensional variation of the displacement at the metal surface. It is shown that strain gradients or curvature of the surface have a pronounced effect on the observed birefringence, and must be taken into consideration. This can be done by means of two correction factors derived in the paper which take into account the elastic properties of the coating and its thickness. An experimental procedure is outlined for determining an unknown distribution of strain at the metal surface on the basis of the observed photoelastic pattern.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Bibliography
Mesnager, M., “Sur la Determination Optique des Tensions Interieures dans les Solides a Trois Dimensions,”Comptes Rendus, Paris 190,1249 (1930).
D'Agostino, J., Drucker, D. C., Liu, C. K., andMylonas, C., “Epoxy Adhesives and Casting Resins as Photoelastic Plastics,”Proceedings of the Society for Experimental Stress Analysis XII (2),123–128 (1955).
D'Agostino, J., Drucker, D. C., Liu, C. K., andMylonas, C., “An Analysis of Plastic Behavior of Metals with Bonded Birefringent Plastic,”Proceedings of the Society for Experimental Stress Analysis XII (2),115–122 (1955).
Author information
Authors and Affiliations
Additional information
The results presented in this paper were obtained in the course of research sponsored by the Ballistic Research Laboratories of Aberdeen Proving Grounds under Contract DA-19-020-ORD-798.
Rights and permissions
About this article
Cite this article
Duffy, J. Effects of the thickness of birefringent coatings. Experimental Mechanics 1, 74–82 (1961). https://doi.org/10.1007/BF02324069
Issue Date:
DOI: https://doi.org/10.1007/BF02324069