Image Analysis of Shear Banding

Plane strain compression tests were performed on Berea sandstone to investigate the mechanisms involved in the development and propagation of a shear band. Thin sections for optical microscopy and digital photographs were prepared by injecting blue-colored epoxy into failed specimens, where deformation localized and softening occurred. The digital image contained three parameters, R, B, and G, that defined the color of each pixel. The intensity...