An interferometric method for the direct evaluation of principal stresses in plane-stress fields

Theocaris, PS; Gdoutos, E

dc.contributor.author	Theocaris, PS	en
dc.contributor.author	Gdoutos, E	en
dc.date.accessioned	2014-03-01T01:37:46Z
dc.date.available	2014-03-01T01:37:46Z
dc.date.issued	1974	en
dc.identifier.issn	00223727	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/21706
dc.subject.other	INTERFEROMETERS	en
dc.subject.other	PLANE STRESS FIELDS	en
dc.subject.other	STRESSES	en
dc.title	An interferometric method for the direct evaluation of principal stresses in plane-stress fields	en
heal.type	journalArticle	en
heal.identifier.primary	10.1088/0022-3727/7/3/315	en
heal.identifier.secondary	http://dx.doi.org/10.1088/0022-3727/7/3/315	en
heal.identifier.secondary	315	en
heal.publicationDate	1974	en
heal.abstract	If a monochromatic and coherent light beam is normally incident on a thin plate under generalized plane-stress conditions, it is analysed into two plane-polarized bundles, whose directions of oscillation coincide with the principal stress directions. The plane-polarized rays are retarded when traversing the plate according to the Neumann-Maxwell law. The absolute variations of the optical paths depend on the thickness and the refractive index variations. Interference of the two primary reflections from the front and rear faces of the plate yields a contour map of the thickness and refractive index in the unloaded state, while the variation of the interference pattern express the variations of these quantities due to loading. If the incident light is successively polarized along either of the principal directions, the interference pattern of the reflected light rays along each direction yields the values of principal stresses. Loading of the specimen creates a displacement of the interference fringes along the field. By counting the number of fringes passing across each point, we can evaluate separately the two principal stresses. This pointwise method is much more sensitive and accurate than classical photoelasticity, since it measures absolute variations of the optical path. The method was applied to a concrete problem of elasticity and compared with other similar methods.	en
heal.journalName	Journal of Physics D: Applied Physics	en
dc.identifier.doi	10.1088/0022-3727/7/3/315	en
dc.identifier.volume	7	en
dc.identifier.issue	3	en
dc.identifier.spage	472	en
dc.identifier.epage	482	en