1998 年 18 巻 1-2 号 p. 15-19
The stress analysis of a three-dimensional photoelastic model having the rotation of the principal stress can be obtained by scattered-light photoelasticity using unpolarized light. The relative phase retardation, ρij, and the secondary principal stress directions, Ψj and Ψj+π/2, of a linear retarder for a distance in the solid model are expressed in terms of measurable Stokes parameters. In this paper, the measurement method of ρij and Ψj was proved on the Poincare sphere. ρij and Ψj were found from the relation of the inner product of the Stokes vectors of the scattered lights from the model and some features of the method were cleared.