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.

在工程结构中，例如大型流体管道，需要对损坏检测进行连续监控。为了解决这个问题，我们使用大型纤维复合换能器的周向条带研究并研究了管道中导波的产生，以产生和检测扭转和弯曲下模。使用Gabor词典对传播的弹性波及其在相互作用波不连续处产生的反射信号和模式转换信号进行后处理，并使用Gabor字典对它们进行基追踪去噪，以改善信号识别能力。在不锈钢管A-36（内径和外径为43.6和48.2毫米）上获得了数值结果并进行了实验测试。