AN ACOUSTICAL IMAGING-SYSTEM USING A LEAKY LAMB WAVE TRANSDUCER

A C-mode acoustical imaging system is constructed by incorporating a leaky Lamb wave device, which has quarterly partitioned and arch-shaped interdigital transducers. The leaky Lamb wave transducer has frequency-dependent radiation angles under multimode operation. For designing the leaky Lamb wave transducer, the transducer efficiency, radiation angle, and the energy distribution rate at the sample surface are considered based on the numerical analysis at the liquid-solid boundary. The usefulness of the system is demonstrated for nondestructive testing to detect a crack on the surface and inside a sample.