Ching-Yuan Chang, Chien-Ching Ma

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 23-24, 2011, DOI:10.3970/icces.2011.018.023

Abstract Electronic speckle pattern interferometry (ESPI) is a full-field non-contact optical technique for displacement and vibration measurement. This study presents an anti-rigid-body motion (ARM) image processing method to improve the image quality of time-averaged ESPI method. The ARM method is based on the statistical optics and has the ability to reduce the perturbed rigid-body motion and background brightness influence. Finite element method (FEM) is applied to evaluate the resonant frequency and mode shape of piezoelectric ceramics, and compared with experimental measurements. In the resonant frequency comparison, ARM method presents 0.13% and 0.82% discrepancy in the third… More >

Helen Hongniao Chen¹, Ray Kai Leung Su¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.15, No.3, pp. 91-102, 2010, DOI:10.3970/icces.2010.015.091

Abstract In this study, Electronic Speckle Pattern Interferometry (ESPI) technique was used to measure the surface displacement and strain fields around cracks in concrete beams. ESPI has high accuracy and can determine full-field deformations of concrete. However, tiny rigid-body movements of beam specimens can spoil the ESPI measurement and cause virtual deformations and false strains. Based on the theory of geometrical optics, this paper proposes a method to eliminate the false strains caused by rigid-body motion. The correction procedure was validated experimentally. Furthermore, the crack evolution in a pre-notched beam is presented. The critical minimum crack More >