ABSTRACT
Abstract Optical field methods like speckle interferometry and grating technique are suitable for measuring displacement distributions of object surfaces. From these the related strain fields can be determined numerically. The procedures are advantageous especially in fracture mechanics for identifying the parameters of material models, which are needed for calculating the fracture onset and the crack propagation or for comparison of the numerically determined deformation distributions. The mentioned methods are explained and applied for deformation measurement of a micro field around the crack tip of a CT specimen and a macro field around the crack tip of a SENB specimen. Keywords: Deformation distribution, digital image processing, grating technique, optical field method, speckle interferometry, strain distribution.
