Abstract: A residual thermal strain distribution measurement method of measuring a residual thermal strain distribution as residual thermal deformation in a sample generated under application of a thermal load, comprises recording images of a periodic pattern present on the surface of the sample by an image recording unit at a first temperature and a sample formation temperature at which the sample is formed, generating moire fringes based on each recorded image of the periodic pattern, calculating a phase of the moire fringes for the sample at the first temperature, calculating a phase of the moire fringes for the sample at the sample formation temperature, acquiring a phase difference of the moire fringes at the sample formation temperature with respect to the first temperature, and calculating a residual thermal strain of the sample at the first temperature with respect to the sample formation temperature based on the acquired phase difference.

Abstract: In a conventional moiré method, achieving both measurement accuracy and dynamic measurement and balancing field of view and measurement accuracy have been difficult. The present invention makes it possible to handle conventional moiré fringes as a grating for generating phase-shifted second-order moiré fringes, use a spatial phase shift method algorithm to accurately analyze the phases of the second-order moiré fringes before and after deformation, and determine shape from the phase differences between gratings projected onto the surface of an object of measurement and a reference surface and determine deformation and strain from the phase differences between the second-order moiré fringes, before and after deformation, of a repeating pattern on the object surface or a produced grating. As a result, it is possible to measure the three-dimensional shape and deformation distribution of an object accurately and with a wide field of view or dynamically and with a high degree of accuracy.

Abstract: A residual thermal strain distribution measurement method of measuring a residual thermal strain distribution as residual thermal deformation in a sample generated under application of a thermal load, comprises recording images of a periodic pattern present on the surface of the sample by an image recording unit at a first temperature and a sample formation temperature at which the sample is formed, generating moire fringes based on each recorded image of the periodic pattern, calculating a phase of the moire fringes for the sample at the first temperature, calculating a phase of the moire fringes for the sample at the sample formation temperature, acquiring a phase difference of the moire fringes at the sample formation temperature with respect to the first temperature, and calculating a residual thermal strain of the sample at the first temperature with respect to the sample formation temperature based on the acquired phase difference.

Abstract: In a conventional moiré method, achieving both measurement accuracy and dynamic measurement and balancing field of view and measurement accuracy have been difficult. The present invention makes it possible to handle conventional moiré fringes as a grating for generating phase-shifted second-order moiré fringes, use a spatial phase shift method algorithm to accurately analyze the phases of the second-order moiré fringes before and after deformation, and determine shape from the phase differences between gratings projected onto the surface of an object of measurement and a reference surface and determine deformation and strain from the phase differences between the second-order moiré fringes, before and after deformation, of a repeating pattern on the object surface or a produced grating. As a result, it is possible to measure the three-dimensional shape and deformation distribution of an object accurately and with a wide field of view or dynamically and with a high degree of accuracy.

Abstract: A fringe image phase distribution analysis technique that performs one-dimensional discrete Fourier transform using temporal intensity information or spatial intensity information to calculate the phase distribution of the fringe image. To improve the analysis accuracy of the phase distribution, a plurality of phase-shifted moiré fringe images is generated from high-dimensional intensity data by a thinning-out (down-sampling) process and an image interpolation process, and the phase distribution of the moiré fringe is calculated by a two-dimensional or three-dimensional discrete Fourier transform. In addition, the phase distribution of thinned-out is added to calculate the phase distribution of an original fringe image. Since high-dimensional intensity information which is present in both spatio-domain and temporal-domain is used, phase distribution analysis is less likely to be affected by random noise or vibration.

Abstract: In the present invention, conventional problems that the scheme is not suitable for nano/micro materials or large structures, and that if the scheme is applied to a regular pattern with two or more cycles of arbitrary repetition, a large error is generated are solved by using a higher order frequency of moire fringes generated using an arbitrary regular pattern having one-dimensional or two-dimensional repetition artificially produced on a surface of an object or previously present on the surface of the object, or phase information in a plurality of frequency components, and improvement of measurement precision and a dramatic increase in a limit of a measurement scale are achieved.

Abstract: A fringe image phase distribution analysis technique that performs one-dimensional discrete Fourier transform using temporal intensity information or spatial intensity information to calculate the phase distribution of the fringe image. To improve the analysis accuracy of the phase distribution, a plurality of phase-shifted moiré fringe images is generated from high-dimensional intensity data by a thinning-out (down-sampling) process and an image interpolation process, and the phase distribution of the moiré fringe is calculated by a two-dimensional or three-dimensional discrete Fourier transform. In addition, the phase distribution of thinned-out is added to calculate the phase distribution of an original fringe image. Since high-dimensional intensity information which is present in both spatio-domain and temporal-domain is used, phase distribution analysis is less likely to be affected by random noise or vibration.