[摘要]：A direct method of determining second-order derivatives of displacement (curvature and twist) using two-channel double-aperture digital shearography is presented. Spatial carrier fringes are incorporated inside the speckle using a double-aperture mask in a two-channel experimental setup. Two sets of slope phase maps are generated that are either shifted in the x direction for curvature measurement or in the y direction for twist measurement. Experimental results are presented to verify the validity of the proposed method. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3359470]
