Time Dependence of Laser-Induced Surface Acoustic Wave on Structural Surface-Breaking Crack Depth

摘要

In this paper, an experimental method was used to study the characterization of surface-breaking crack with varied depths by laser-generated surface acoustic wave (SAW). We analyzed the time-dependence relationship between Rayleigh waveform features and surface-breaking crack depth, founded that the waveform time-domain features of SAW gradually increased with the increasing of crack depths. Then we theoretically analyzed the formation mechanisms of the waveform time-domain features, and deduced the mathematical relationship of SAW time-domain characteristic quantities and surface defects depth. The experimental results showed that the time-domain characteristic quantities of SAW can achieve the quantitative detection of surface-breaking cracks with a depth range of 0.1mm~1.0mm. The experimental results agree well with the theoretical results. The research findings would provide a potential application in nondestructive testing surface-breaking crack of turbine blades and aircraft parts