Laser ultrasonic damage detection in coating-substrate structure via Pearson correlation coefficient

摘要

This study explores the feasibility of using laser generated ultrasonic wave to detect the interfacial damage of coating-substrate structure. Two Pearson correlation coefficient based post processing algorithms are respectively modified and used in order to evaluate the damage-induced waveform variation and thus position the damage accurately. In addition, the ultrasonic signals of frequency-domain and time-domain are separately studied to optimize the damage visualization performance of the two approaches. The proposed method helps to facilitate nondestructive examination of laser ultrasonic technique.