Two-scale digital speckle technique for measurement of complicated strain field

This paper suggests a two-scale DSCM (digital speckle correlation method) for measurement of complicated strain field. The main idea of the method is to use CCD lenses with different magnifications to capture different scale speckle images: the large-scale images can be used to measure the full field of strain and find the strain concentration area (SCA), but the strain values of the SCA may be in bad precision. So the small-scale images are specified to measure the strain distribution in SCA and can obtain more precise result. The two-scale DSCM is a good solution to the measurement of complicated strain field.