Abstract:

A shadow-moire instrument is investigated, which can be applied to measurement of three-dimensional shape and deformation. The shadow-moi-re method is quite suitable for pattern measurement in the field where holographic interferometry is not available. First, based on Fourier optics, the luminous intensity formula is inferred to explain shadowmoire in term of theory. Then, the. features of. shadowmoire instrument are described as follows; 1 ) large size of its grating, its high precision and ease of its production; 2 ) ability of grating to reciprocate along its main direction for increasing the signal-to-noise ratio of pattern; 3 ) a precision serpentine push-type system of the instrument at the main optical axis direction to conduct the fringe interplating technique. Finally, its application in shell structure stability research and measurement of-aerofoils of rotor blades are introduced.