20 April 1995 Electronic shearography for bridge inspection
Author Affiliations +
Abstract
Electronic shearography (ES) is a laser based non-destructive testing method that has the potential to be developed into a commercial bridge monitoring technique. The primary advantage of ES over other similar techniques like electronic speckle pattern interferometry (ESPI) is its decreased sensitivity to in-plane rigid body movement and vibrations. Bridge inspection with ES has proven to be a daunting task so far. The main problem has been the inability of the method to handle the large deflections and vibrations that might be expected in a typical bridge subjected to normal service loads. Earlier research has shown that the extent of in-plane movement that can be tolerated by the system is dependent on the speckle size. The speckle size also affects the fringe quality by imposing resolution requirements on the imaging device. This article shall undertake the study of speckle size as a function of the focal length of the imaging lens, object distance and illumination wavelength using high resolution holographic film and a high magnification optical microscope.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Debashis Satpathi, Arup K. Maji, "Electronic shearography for bridge inspection", Proc. SPIE 2446, Smart Structures and Materials 1995: Smart Systems for Bridges, Structures, and Highways, (20 April 1995); doi: 10.1117/12.207726; https://doi.org/10.1117/12.207726
PROCEEDINGS
11 PAGES


SHARE
Back to Top