SEPARATION OF FLEXURAL AND EXTENSIONAL MODES IN MULTI MODAL ACOUSTIC SIGNALS

摘要

Methods for separating flexural and extensional mode signals from a multi-modal signal are provided. In one embodiment, a method includes emitting an ultrasonic pulse to excite a multi-modal Lamb wave in a pipe and then detecting acoustic signals generated from the Lamb wave. The detected acoustic signals are processed to separate the extensional and flexural mode signals. This processing can include filtering the detected acoustic signals with filters that are based on quality factors and dispersion characteristics for the individual modes to produce sets of coefficients, selecting subsets of the coefficients, and using the selected subsets to predict extensional and flexural mode waveforms that are based on the estimated quality factors for the individual modes. Additional methods, systems, and devices are also disclosed.