Application of an optimized digital correlation method to planar deformation analysis

摘要

An optimized digital correlation method (DCM) has been developed to improve previously reported iterative DCMs. The optimized method is shown to be much faster than previous methods while achieving accuracy equivalent to that obtained via simple coarse-fine iterative techniques. The optimized correlation routine employs the Newton-Raphson method with differential corrections to minimize search time. The paper illustrates the optimized DCM and presents a simple flowchart of a practical program. Experiments indicate that the optimized DCM is successful in displacement measurement. In direct strain measurement, however, both DCMs using a coarse-fine search routine and those using the proposed optimized correlation procedure are shown to have large variability in the computed strains.