A mathematic model of a spherical len with continuous longitudinal wave for ultrasonic testing has been introduced in the paper. The calculation formulas of the acoustic radiation pressure on the axis of the sound field and the acoustic focal length of the spherical len have been put forward based on the analysis of geometrical and physical acoustics. The relations between the curvature radius of the len, or the test frequency, or the diameter of the probe's crystal with the focal length and the maximum amplitude of acoustic radiation pressure (that means the focusing degree) are investigated theoretically and experimentally. All the results provide scientific basis for designing a high performance focusing probe with a long focal length. All the theoretic calculations and focusing laws agree with the experiments quite well.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.full paper not received Publisher:Ashgate Publishing Company
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