Defect feature extraction using surface wave interactions and time-frequency behavior

Abstract

In this paper we exploit the interaction of ultrasonic surface waves with surface cracks in order to extract defect characteristics. An experimentally validated computer model was developed to simulate laser generated surface waves interacting with defects of several depths and angles. The Rayleigh reflection coefficient vs. crack angle and depth was explored. Amplitude and frequency behaviour at the defect interface in aluminium samples was also considered. Additionally, the phase component of the FFT was used to extract similar information. Finally, we explore the time-frequency behaviour using the Wigner transform. © 2010 American Institute of Physics.