Application of chirplet transform for detecting axial cracks in pipes using torsional guided modes

作者：Kim Y W; Park K J^*

来源：Insight, 2017, 59(3): 138-+.

DOI：10.1784/insi.2017.59.3.138

• mode separation
• chirplet transform
• reflection coefficient
• axial defect
• magnetostrictive sensor

A quantitative study of the interaction of the T(0,1) torsional mode with axial defects in a pipe is presented in this paper. A mode decomposition technique employing the chirplet transform, which is able to separate the individual modes from dispersive and multimodal waveforms, measured using a magnetostrictive sensor with a single continuous transducing element, is used to separate the multimodal signals reflected from the axial defects. Reflection signals are obtained from experiments on a carbon steel pipe. Results show that the reflection coefficient of the axial crack initially increases with the crack length, but finally reaches an oscillating regime. It is also shown that the axial crack can be identified by the consecutive occurrences of the modes with negligible dispersion and the crack size can be estimated using the reflection coefficient of the first pulse.

• 出版日期2017-3