Vibrations of a hollow piezoelectric ceramic sphere

ABSTRACTS The abstracts survey, a regular feature of each issue of ULTRASONICS, contains recent patent information and reports of new literature in the field. Copies of original articles are best obtained by writing to the journal in which they appeared. The addresses of these journals can be found in reference books such as ‘World List of Scientific and Technical Publications’, ‘Willings Press Guide’, ’ Newspaper Press Directory’, or (for American journals) ‘Ayers’.

SONICS Piezoelectric

AND

ULTRASONICS

response of a ferroelectric

memory array Crawford, J. C. Vol SU-19 No 2 (April 1972) pp 139-146 The information stored in a twodimensional ferroelectric memory array can be read out non-destructively by sensing the piezoelectric response of the individual bits. This piezoelectric response is studied experimentally for an individual bit that is electrically isolated from, but elastically coupled to, the rest of the array. Results show the presence of travelhng acoustic waves that produce transient word-to-word piezoelectric coupling as well as static coupling between adjacent words due to the strain component parallel to the word electrodes.

SOVIET

PHYSICS-ACOUSTICS

Ultrasonic amplitude and phase recording method based on the double interaction of light with sound

Bobkov, Yu. A., Zverev, V. A. Vol17 No 4 (April-June 1972) pp 450-453

Determination of the acoustic load impedance in the ultrasonic machining of glass Boidek, S. A., Golyamina, I. P., Margolin, v. s. Vol17 No 4 (April-June 1970) pp 460-463

The parameters of the equivalent circuit of the vibratory system of an ultrasonic machine tool used to cut glass have been determined. Its efficiency and acoustic-load impedance have been estimated by means of an apparatus capable of generating impedance diagrams of the transducers in operation. Calibrating particle-velocity Zakharov, L. N.

Vol17 No 4 (April-June

hydrophones

1972) pp 474-477

Methods are discussed for the calibration of particle-velocity (pressure gradient) hydrophones in a flat layer of water having an acoustically compliant lower boundary (fresh-water reservoir) with a sound-pressure pickup used as the reference hydrophone. The experimental results of the calibration show good agreement with theoretical calculations. Calculation

of the gain of closed homoge-

neous cylindrical acoustic lenses Kanevskii, I. N., Surikov, B. S. Vol 17 No 4 (April-June 1972) pp 478-481

A method is investigated for the visualization of progressive sound waves in a liquid such that both the amplitude and phase of the field are recorded. Tht method is based on the successive interaction of light with two ultrasonic waves. The field recording schematic is described, and examples of wave visualization are given.

The sound pressure and particle velocity gains are calculated for closed homogenous lenses having phase aberration of arbitrary magnitude. The existence of a limiting gain value is established.

Static-pressure dependence of the cavitation erosion intensity in liquid oxygen

Vibrations of a hollow piezoelectric ceramic sphere Lazutkin, V. N. Vol17 No 4 (April-June 1972) pp 496-499

Bogachev, I. N., Korobeinikov, V. P. Vol 17 No 4 (April-June 1972) pp 454-459 A method and apparatus are described for the experimental investigation of the cavitation erosion of materials in liquid oxygen. The dependence of the erosion activity and ultrasonic frequency is studied. It is shown that with an increase in the static pressure the erosion intensity is increased by several orders of magnitude; increasing the frequency decreases the erosion activity of the cavitation zone. An explanation is offered for the results obtained in the study.

ULTRASONICS.

SEPTEMBER

1972

A solution

of the dynamical

problem is

given for a piezoelectric ceramic resonator in the form of a hollow sphere with radial polarization. The frequency equation is grven, along with the displacement distribution laws at the radial-mode resonances, including ‘peripheral’ and ‘thickness’ resonance. By taking account of the influence of the piezoelectric effect on the elastic constants and anisotropy of the material it is possible to extend the results of the analysis to present-day piezoelectric ceramics.

Frequency characteristics of a compensatedcapacitance piezoelectric ceramic receiver Komarkas, V. I., Kazhis, R.-I. Yu. Vol 17 No 4 (April-June 1972) pp 514-515 Influence of ultrasonic strain on diffusion in an iron-zinc system Kulemin, A. V. Vol17 No 4 (April-June 1972) pp 518-520 The hydrostatic effect in measurements of the velocity of ultrasound in the critical region of individual substances and complex solutions Nozdrev, V. F., Peturkhov, P. S. Vol 17 No 4 (April-June 1972) pp 523-526 Determination of critical temperatures from ultrasonic data in azeotropic hexane-ethnaol

mixtures Tashmukhamedov, F. Vol17 No 4 (April-June

MATERIALS

1972) pp 5277528

EVALUATION

Ultrasonic procedure urn aircraft wheels

for inspecting

alumini-

Guzi, C. E., Robertson, J. W. Vol30 No 5 (May 1972) pp 109-112 An ultrasonic inspection procedure has been developed for testing aircraft wheels. The procedure requires lo- 15 minutes and can be conducted while the wheels are on the plane. The sound is introduced through the wheel weight boss 90 degrees to the direction of crack propagation. Cracks as small as 0.38 mm deep and 6.35 mm long can be detected. This is the only method that has found a crack before complete failure. Proposed course outline for teaching nondestructive testing in vocational and technical schools and junior colleges Stokes, V. L. Vol30 No 7 (July 1972) pp 19A-42A

JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA Interference effect in a multifrequency ultrasonic pulse echo and its application to flaw characterization Adler, L., Whaley, H. L. Vol51 No 3 Part 2 (March 1972) pp 881

887

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