Quantitative identification of small defects in pipes using ultrasonic guided waves and synchronized Lorenz equations

Defect quantification and signal processing is the important and fundamental problems in ultrasonic guided wave inspection of pipelines. However, the existing methods struggle to accurately identify low SNR guided wave and quantify defects. To overcome this disadvantage, a quantitative detection of small defect in pipeline using synchronized Lorenz equations and guided wave was proposed. Firstly, a method for the quantification and localization of small defects in pipes was developed using the relationship between reflection coefficients, section loss rates and signal amplitudes. Then, two synchronized Lorenz equations were constructed to identify small defects echo. Theoretical derivation and simulation studies showed that the synchronization error can accurately identify the amplitude and peak arrival time of guided waves under strong noise. Finally, experimental research on guided waves inspection of pipeline showed that it could quantitatively identify a pipe small defect with a section loss rate of 2 %. The errors in the defect size and location identification were less than 5 % and 2 %, respectively. Compared to existing study, this study improved the sensitivity of guided waves inspection for the small defect in pipe and its applicability under noise interference.