Title :
New design and analysis for point-focusing of surface waves in contact testing
Author :
Kim, B.G. ; Lee, J.O. ; Lee, S.
Author_Institution :
Nondestructive Evaluation Lab., Korea Res. Inst. of Stand. & Sci., Taejon, South Korea
fDate :
3/1/1993 12:00:00 AM
Abstract :
A method was presented for the intensive focusing of surface ultrasonic waves in contact testing, and an ultrasonic contact transducer was fabricated and characterized. The acoustic contact lens of the transducer was in a shape which was obtained by rotating a right-angled triangle having a critical angle for the generation of surface waves. PVDF film was employed as an ultrasonic transmitter and receiver. The fabricated transducer showed the focusing feature of a narrow lateral half width and high sound intensity at a focal point. Also, a simple model was presented to estimate theoretically the stress pattern on a symmetry axis of the transducer. The stress pattern predicted using the model showed good agreement with the experimental result. This concept can also be used in acoustic microscopy.<>
Keywords :
acoustic microscopy; focusing; mechanical contact; surface acoustic waves; ultrasonic materials testing; ultrasonic transducers; PVDF film; US receiver; acoustic contact lens; acoustic microscopy; contact testing; high sound intensity; narrow lateral half width; point-focusing; stress pattern; surface ultrasonic waves; surface waves; ultrasonic contact transducer; ultrasonic transmitter; Acoustic testing; Acoustic transducers; Estimation theory; Lenses; Shape; Stress; Surface acoustic waves; Surface waves; Transmitters; Ultrasonic transducers;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
