[3A4] Enhancements to the performance of ultrasonic guided wave testing on coated pipelines using split-spectrum processing
K Pedram1, M Deere2 and M Ghafourian3
1University of Greenwich, UK
2TWI Ltd, UK
3Brunel University, UK
Ultrasonic guided wave (UGW) technique is widely utilized in numerous industry areas for the inspection of pipelines where the structural integrity is of concern. Guided wave testing is capable to inspect long length of pipes from one signal location using transducers that positioned circumstance around the pipe. Due to dispersive propagation and multimodal of this technique, the received signal is usually degraded and noisy that reduce the sensitivity to small defects and inspection range. Hence, identify small defects and signal interpretation is often a challenging task in such a system particularly for coated pipelines where the attenuation rates are considerably higher compared with a bare pipe. This paper proposes a novel solution to address this issue by utilizing an advanced signal processing method named “split-spectrum processing” (SSP) to reduce the level of coherent noise and enhance the spatial resolution in such signal. The optimum parameters of SSP have been already identified for bar pipe and in this paper, the proposed method has been experimentally compared with the conventional approach for a coated pipe. The result illustrated that the proposed method has significantly increased the signal-to-noise ratio (SNR) and spatial resolution of the UGW signal.
