ABSTRACT
Grid and moiré methods have been the cornerstone of deformation and strain measurements. The grid method has its foundations in the definition of normal strain, which is the change in length of a line segment, and shear strain, which is the change in the angle of two line segments originally perpendicular to each other. We could thus measure over the whole field with a resolution proportional to grid spacing that is to be printed on the object to be measured. Over the years, this period has reduced from micrometers to nanometers. Furthermore, recording of these deformed grids has also evolved from using camera-based imaging to interferometric methods to SEM and atomic force microscopy methods. In this chapter, some novel advances in moiré and grid methods, using various microimaging devices, are exemplified, with specific applications to micromeasurement.
