Moiré pattern

About: Moiré pattern is a research topic. Over the lifetime, 1917 publications have been published within this topic receiving 27176 citations. The topic is also known as: moiré fringes & moire pattern.

Dynamic shape and strain measurements of rotating tire using a sampling moiré method

Abstract: Shape measurements and strain distribution measurements are important for analyzing the behavior of a rotating tire Recently, a two-dimensional phase analysis method using phase-shifting moire patterns, which are generated computationally from a two-dimensional grating image, was proposed This method is well suited to the dynamic shape and strain measurement because the phase can be accurately obtained from a two-dimensional grating image We show that it is possible to analyze the strain distribution and shape measurements of a moving object using a grating pattern attached to the surface of the specimen, and a dynamic shape and strain measurement system using the sampling moire method is developed in this paper The principle of the method and the experimental results of the method when applied to a rotating object are shown

Contouring by Moire Interferometry

Abstract: A double-exposure moire-interferometry technique for topographic contour measurement of an arbitrarily curved object is presented. A curved surface coated with light-sensitive material is exposed twice in a volume of virtual gratings formed by the interference of two coherent light beams split from a laser. An adequate rotation of the curved surface relative to the virtual grating between the two exposures produces moire fringes which reveal topographic contour, or contour under some conditions, of the surface. The advantage of the present method in comparison with others is that it offers both reasonably good fringe quality and easily adjustable high sensitivity. The sensitivity of the technique is shown to be from the order of micrometer to that of millimeter depending on the frequency of the virtual grating and the amount of the relative rotation. This technique was successfully applied to the topographic contour measurement of a cylindrical shell with and without a diametrical point loading. The principle of this paper and some early results were presented at the SPIE conference held at Dearborn, MI on June 27–30, 1988 and appeared in its proceeding.1

Displacement and Strain Measurement by Circular and Radial Gratings Moiré Method

Abstract: Direct digital moire method of circular and radial gratings with its phase shifting technique is proposed and applied in a mixed-mode fracture problem of large deformation materials. Circular and radial curves are used as both reference and specimen gratings in this digital moire method for deformation measurement. And phase shifting technique is automatically implemented directly on circular and radial fringes, which facilitates obtaining displacement fields in polar coordinate system, radial u r and circumferential u θ , and strain fields e r, e θ , e rθ are calculated subsequently. Application of the direct digital moire method of circular and radial gratings in a mixed-mode fracture problem with large deformation illustrates the process of this method, and also demonstrates its feasibility and validity for large deformation materials.