Deformation of ultrasonic pulse with diffraction

摘要

When studying a homogeneous material as an ultrasonic transmission system, a complicated effect to the ultrasonic pulses can be seen within it, and an important approach in analyzing this system is to compute the retarded potential of the ultrasonic field. The aim of this paper is to investigate particle velocity, together with sound pressure, and to perform a comparison of the results obtained. Deformation of ultrasonic pulse with diffraction is dealt with by utilizing a numerical method, using a digital computer — in this case the pulse is transmitted from a circular flat transmitter into an isotropic and non-absorptive material. The analyzed transmitting pulses are assumed to have several kinds of duration, with envelopes of ramp followed by exponential decay, or with envelopes of the square of a sinusoidal wave. The shapes of the received pulses can be derived with the use of several transmission systems, by both a circular flat transducer and a point transducer, and by a pair of circular flat transducers. The ratios of the Peak values of the received pulses to transmitted pulses are computed for both particle velocity and sound pressure. These values correspond to the apparent attenuation of the pulsed ultrasonic wave by beam divergence. rights reserved.