Title :
Three-dimensional crack depth profile assessment using near-field surface acoustic wave signal response
Author :
Blackshire, James L.
Author_Institution :
Air Force Res. Lab. (AFRL/RXLP), Wright-Patterson AFB, OH, USA
Abstract :
A method for determining the three-dimensional depth profile of a surface-breaking crack-like feature is presented based on near-field surface acoustic wave signal responses. Three-dimensional finite element models were used to study the forward problem, where the characteristic near-field scattering of a surface acoustic wave incident on a simulated crack was investigated. Experimental validation of the modeling predictions was accomplished using a wedge transducer for surface wave generation and a scanning laser vibrometry system for surface wave detection. The characteristic near-field amplitude response in reflection and in transmission was measured and modeled for flat-bottom, angled, and curved-bottom localized notch features, where a simple linear inversion method was developed, which provided an effective means for characterizing and mapping the three-dimensional depth profile of surface-breaking crack-like features with depths in the micron to millimeter range.
Keywords :
finite element analysis; surface acoustic wave signal processing; surface acoustic wave transducers; characteristic near-field amplitude response; characteristic near-field scattering; localized notch features; modeling predictions; near-field surface acoustic wave signal response; scanning laser vibrometry system; simple linear inversion method; simulated crack; surface acoustic wave incident; surface wave detection; surface wave generation; surface-breaking crack-like feature; three-dimensional crack depth profile assessment; three-dimensional finite element models; wedge transducer; Scattering; Surface acoustic waves; Surface cracks; Surface morphology; Crack Depth Profile; Near Field Scattering; Surface Acoustic Wave;
Conference_Titel :
Ultrasonics Symposium (IUS), 2011 IEEE International
Conference_Location :
Orlando, FL
Print_ISBN :
978-1-4577-1253-1
DOI :
10.1109/ULTSYM.2011.0448