Although Electronic Speckle Pattern Interferometry (ESPI) is a well known optical technique which can provide stationary vibration patterns with high spatial resolution, it has not yet became a widespread methodology in modal analysis and related areas such as system identification and updating. The main reason for such situation can be recognized in the difficulties of the retrieval of quantitative information about modal parameters from the fringe pattern images. In this paper an algorithm based on the Hilbert transform is presented, it is capable of extracting mode shapes from the fringe pattern images obtained by Time Average ESPI, which is the easiest procedure for applying ESPI to modal analysis. Starting from the paper which Hilbert was firstly adopted, the method has been applied to numerical examples of a cantilever beam and plate.
Image Processing for Fringe Unwrapping in Speckle Interferometry / Agneni, Alessandro; M. A., Caponero; Paolozzi, Antonio. - 2:(2000), pp. 1479-1484.
Image Processing for Fringe Unwrapping in Speckle Interferometry
AGNENI, Alessandro;PAOLOZZI, Antonio
2000
Abstract
Although Electronic Speckle Pattern Interferometry (ESPI) is a well known optical technique which can provide stationary vibration patterns with high spatial resolution, it has not yet became a widespread methodology in modal analysis and related areas such as system identification and updating. The main reason for such situation can be recognized in the difficulties of the retrieval of quantitative information about modal parameters from the fringe pattern images. In this paper an algorithm based on the Hilbert transform is presented, it is capable of extracting mode shapes from the fringe pattern images obtained by Time Average ESPI, which is the easiest procedure for applying ESPI to modal analysis. Starting from the paper which Hilbert was firstly adopted, the method has been applied to numerical examples of a cantilever beam and plate.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.