High-speed digital image correlation: error estimations and applications

Among the different optical measurement techniques for full-field analysis of displacements and strains, digital image correlation (DIC) has proven to be very flexible, robust, and easy to use, covering a wide range of different applications. DIC measurement results, among others, are influenced by the systematic errors of the measurements system, a major source of which is due to imaging system calibration. We present a 3-D DIC system that provides online error information concerning diverse error sources, and even more important, the propagation of errors throughout the calculations to the resulting contours, displacements, and strains. On the basis of this system we discuss error sources, error propagation, and the impact on correlation results. Performance tests for studying the impact of calibration errors on the resulting data are shown for static and dynamic applications. (C) 2007 Society of Photo-Optical Instrumentation Engineers.