Enhancement of ultrasonic surface waves at wedge tips and angled defects Enhancement of ultrasonic surface waves at wedge tips and angled defects
نویسندگان
چکیده
The behaviour of sound waves interacting with wedges has attracted interest from researchers in geophysics and non-destructive testing. We consider here the nearfield behaviour of Rayleigh waves incident on wedges and surface-breaking defects which propagate at an angle to the surface, such as rolling contact fatigue on rails. It has been shown that, for a detection point on the edge of the crack tip, a very large signal enhancement is observed for shallow angles. We explain this behaviour through considering the effect of the defect geometry, with changes in the frequency·thickness product leading to mode-conversion of the incident Rayleigh wave.
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