High-Sensitivity Measurement of Strain by Moire Interferometry

Abstract

Moire interferometry is a useful method of measuring small displacement distribution in the whole field of a specimen. However, it is difficult to make diffraction gratings and to measure small strains of less than 10-3. In order to facilitate the use of moire interferometry, we attempted to mass-produce sheets of diffraction grating by hot-press printing. By transferring the grating of one such sheet, we were able to create a diffraction grating on a specimen. To improve the sensitivity of moire interferometry, we applied a multiplication method to it. As a result, strain of the order of 10-4 was measured.