Deformation and Rigid-body-motion Measurement by Multiple Interferometric Strain/Slope Rosettes

In Part I, the Multi-ISSR measurement theory was given and validated for a three-indentation ISSR. Part II shows how fringe analysis is carried out by applying the theory to real measurement problems. Two-dimensional image processing techniques are applied to both the ISSR and the Multi-ISSR. The procedures are demonstrated through a bending experiment where a four-indentation Multi-ISSR is used. A practical example is given to demonstrate the numerical procedure involved in extracting the diffraction pattern, and calculating the shift of the zero-order diffraction peak to measure rigid-body-motion. Fringe pattern analysis includes numerical fringe separation and phase shift determination. Three practical approaches of obtaining strains by solving the governing equations relating phase shifts with strains and rigid-body-motion are discussed.