Application of Circular and Radial Gratings in Digital Moire Method

摘要

Circular and radial gratings are used in digital moire method in order to obtain in-plane displacement and strain information denoted in polar coordinate system directly. Four-step phase-shifting technique is achieved by shifting the computer-generated reference radial and circular gratings precisely. Basic procedures of this novel digital moire method with circular and radial gratings are explained in detail by an experimental application for large deformation analysis on a double-cracked rubber disk. By using deformed gratings, radial and circular displacements distributions are measured and distributing information of strains can also be calculated. Results of the application show that the present digital moire technique of circular and radial gratings is a valid and efficient way in measurement of both displacement and deformation for large deformation materials.