Detection of torsional guided wave generation using macro-fiber composite transducers and basis pursuit denoising

Abstract

In engineering structures, such as large fluid-filled pipelines, continuous monitoring for damage detection is needed. To address this issue, we study the generation of guided waves in pipes by using a circumferential strip of macro fiber composite transducer to generate and detect torsional and flexural lower modes. The propagated elastic waves and their resulting reflected and mode-converted signals at the interaction wave discontinuity are post-processed with basis pursuit denoising using a Gabor dictionary to improve signal identification. Numerical results are obtained and experimentally tested on a stainless-steel pipe A-36 (43.6 and 48.2 mm in inner and outer diameter). It was found that the proposed method makes it possible to identify an artificial discontinuity by detecting the scattered wave and converted modes of a propagated torsional wave.