A METHOD FOR SEPARATION OF STRESSES IN TWO- AND THREE-DIMENSIONAL PHOTOELASTICITY

Abstract

A method for separation of stresses in two and three-dimensional photo elastiily using the harmonisation of first stress invariant along a straight section is developed. For two-dimensions, the equations of equilibrium are reformulated in terms of sum and difference of normal stresses and relations are obtained which can be used for harmonisation of the first invariant of stress along a straight section.

A similar procedure is adopted for three-dimensions by making use of the Beltrami-Michell equations. The new relations are used in finite difference form of evaluate the sum of normal stresses along straight sections in a three-dimensional body. The method requires photoelastic data along the section as well as adjacent sections. This method could be used as an alternative to the shear difference method for separation of stresses in photoelasticity. The accuracy and reliability of the method is verified by applying the method to problems whose solutions are known.