In this work a new time-frequency procedure for the extraction of multimodal and dispersive guided waves (GWs) in long bones from a recorded time-waveform is presented. The proposed method is based on a basis pursuit algorithm. The ultrasonic wave is represented as a linear superposition of elementary signals, called atoms. Atoms are designed to match the spectro-temporal structures of the different propagating GWs by using a Warped Frequency Transform (WFT). The atomic distribution produces a new time-frequency representation (TFR) suitable to characterize GWs, as each atom can be associated to a particular propagating mode. An application to propagating GWs in long bones is presented to show the potential of the proposed procedure.
L. De Marchi, Kailiang Xu, De-an Ta, A. Marzani, S. Caporale, N. Speciale (2009). Warped Signal Dictionaries for the Analysis of Ultrasonic Guided Waves in Long Bones. ROMA : IEEE UFFC Society.
Warped Signal Dictionaries for the Analysis of Ultrasonic Guided Waves in Long Bones
DE MARCHI, LUCA;MARZANI, ALESSANDRO;CAPORALE, SALVATORE;SPECIALE, NICOLO'ATTILIO
2009
Abstract
In this work a new time-frequency procedure for the extraction of multimodal and dispersive guided waves (GWs) in long bones from a recorded time-waveform is presented. The proposed method is based on a basis pursuit algorithm. The ultrasonic wave is represented as a linear superposition of elementary signals, called atoms. Atoms are designed to match the spectro-temporal structures of the different propagating GWs by using a Warped Frequency Transform (WFT). The atomic distribution produces a new time-frequency representation (TFR) suitable to characterize GWs, as each atom can be associated to a particular propagating mode. An application to propagating GWs in long bones is presented to show the potential of the proposed procedure.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
