Fourier transform method of fringe analysis for moiré interferometry

An automated Fourier-transform method of phase retrieval of moiré interferometric fringe pattern is presented. The method is shown to provide fast and accurate determination of the phase information by removing the carrier without shifting in frequency domain the filtered Fourier spectrum of the carrier-modulated moiré fringe pattern. The principle of the method is described and moiré interferometric measurements with submicron sensitivity of the in-plane displacement fields of thick carbon-fibre/PEEK composite laminates are analysed as an example of the application of the technique.