Whole-field measurement of three-dimensional stress by scattered-light photoelasticity with unpolarized light

Abstract

In digital scattered-light photoelasticity with unpolarized light (DSLPUL), secondary principal stress direction ψ j and total relative phase retardation ρ jtot in a three-dimensional stressed model with rotation of the principal stress axes are obtained by measuring Stokes parameters of scattered light from optical slices. The present paper describes intelligibly the principle of DSLPUL, and then demonstrates that the ψ j and ρ jtot in a frozen stress sphere model are nondestructively measured over the entire field.