Determination of the optically equivalent model in three-dimensional photoelasticity

Abstract

Any stressed photoelastic medium can be reduced to an optically equivalent model consisting of a linear retarder, with retardation δ₁ and principal axis at azimuth Φ1, and a pure rotator of power Φ2. The paper describes two simple methods to determine these quantities experimentally. Further, a method is described to overcome the problem of rotational effects in scattered-light investigations. This new method makes use of the experimentally determined characteristic parameters.