Application of PNLMS and DTW to analyze overlapped Lamb waves
Jianan Pan, Long Yu · IOP Conference Series Materials Science and Engineering · 2019
A method based on Proportional Normalized Least Mean Square (PNLMS) and Dynamic Time Warping (DTW) is present in this paper for the analysis of the overlapped Lamb waves. The damage information, including location, severity and type, can be assessed based on the characteristics of damage reflected Lamb waves. However, the damage reflected waves can be easily masked by the waves reflected by the boundary, especially for the scenario when the damages adjoin to boundaries. The overlapped waveforms are difficult to analyse using conventional filtering methods since the waveforms reflected by damages and boundaries have identical frequency characteristics. The methods developed in the area of audio echo-hiding processing has been introduced to solve this problem. Improvements has been made with considering the requirement of Lamb waves-based damage detection. The results from numerical simulation show that the presented method is superior to conventional methods in both stability and accuracy.