Method for visualization of macrodefects of dynamic periodic structures, based on the effect of the emergence of muar strips

Abstract

Of particular interest are objects characterized by a tunable periodic structure. The structure parameters of such objects change not only in space, but also in time. The study of behavior in space and visualization of defects in periodic structures is one of the main tasks of measuring control. The paper proposes a simple method of visualization of macrodefects of dynamic periodic structures based on the effect of the appearance of moire fringes. An easy-to-use visualization method involves registering a series of snapshots of a dynamic periodic structure followed by combining a selected pair of snapshots. The devices for recording a series of snapsohts and forming moiré paintings are described. A feature of the implementation of this method of visualization of macrodefects is the possibility of using incoherent light both when registering snapsohts and in the process of forming moire fringes. When creating a device for implementing the method, household LED lamps A60 with a matte bulb were used as light sources. A series of moire patterns was obtained, visualizing the spatial position of the macrodefect of the mask surface at various points in time of its mechanical deformation. A pattern of moire fringes, visualizing the position of a macrodefect of a periodic structure, was recorded by a digital camera and displayed on a personal computer monitor screen.