Patent ID: 8818746
Filing Date: 2014-08-26
Classification: G01N

Abstract:
1. A method for establishing the size of a defect in a thick-walled, cylindrical geometry comprising, (1) creating an acoustic vibration in that geometry; (2) detecting the vibration which results; (3) filtering that signal, to remove extrinsic noise; and (4) analyzing, on a general purpose computer, the resulting frequency pattern of the vibration by (a) using a Fourier transform to decompose the filtered frequency signal into its constituent major frequencies or spectrum; (b) computing the decay coefficient of the time series data; and (5) using a Bayes maximum likelihood statistical pattern classification algorithm to compare this decay coefficient to a library containing the decay coefficients of similar thick-walled, cylindrical geometries with varying size cracks therein, to determine the particular crack size thereof by correlating with the library data.