Error analysis and correction equations for a real-time phase-shifting method using circular polariscope-based photoelasticity

Abstract

The use of a polarization camera to achieve real-time phase shifting in circular polariscope-based photoelasticity is limited due to quantitative error analysis and correction. In particular, the primary factor limiting this method is the mismatch between the quarter-wave plate and the wavelength of the light source. In this regard, this study proposes error correction equations for the instantaneous phase-shifting method based on theoretical analysis and simulation of a diametrically stressed disc. First, the error distributions of the stress direction angle and phase retardation are discussed, and the correction equations of the isochromatic and isoclinic lines are deduced. Subsequently, we consider the phase ambiguity problem caused by the phase absolutization. Finally, the error analysis and correction methods are verified experimentally on the diametrically compressed disc.