TECHNIQUE AND DEVICE FOR THE EXPERIMENTAL ESTIMATION OF THE ACOUSTIC IMPEDANCE OF VISCOELASTIC MEDIUM

Measuring the characteristics of process fluids allows us to evaluate their quality, biological tissues – to differentiate healthy tissues and tissues with pathologies. Measuring the characteristics of process fluids allows us to evaluate their quality, biological tissues – to differentiate healthy tissues and tissues with pathologies. One of the complex acoustic parameters is the impedance, which allows one to fully evaluate the characteristics of viscoelastic media. Most of impedance methods of measurements require using two or more reference media and the availability of calibrated acoustic transducers. The aim of this work ware introduced a methods and construction for the experimental evaluation of the longitudinal and shear impedance of viscoelastic media based on measuring the parameters of the amplitude-frequency characteristics and calculating the elements of the electric circuit for replacing the piezoelectric element which vibrating in the test medium.

The paper introduces a methods and construction of the experimental evaluation of the impedances of viscoelastic media. The suggested methods is allowed measuring longitudinal and shear impedances and determining velocities of longitudinal and transverse ultrasonic waves and the values of the elastic moduli of viscoelastic media, including in various aggregate states. The technique is fairly simple to implement and can be reproduced using simple laboratory equipment.

The obtained values of the acoustic impedances of the investigated media are in satisfactory agreement with their reference data. In contrast to the known methods for determining the acoustic impedance, the developed technique allows us to estimate with sufficient accuracy the parameter of the shear impedance of viscoelastic media that is difficult to measure at the frequencies of the megahertz range, which determines the shear modulus of the material and characterizes its resistance to shear deformations. The results of the implementation of the developed technique for the estimation of acoustic parameters for a number of media with zero shear elasticity (alcohol, acetone) and viscoelastic media (glycerin, architectural clay, silicone sealant and glue МР-55 before and after polymerization) are presented.

1. Muraviev V.V., Tapkov K.A. [Evaluation of strain-stress state of the rails in the production]. Devices and Methods of Measurements, 2017, vol. 8, no. 3, pp. 263–270 (in Russian). doi:10.21122/2220-9506-2017-8-3-263-270

2. Muraviev V.V., Muravieva O.V., Dedov A.I., Baiteryakov A.V. [Monitoring of the metal structural state by acoustical structural noise]. Devices and Methods of Measurements, 2014, vol. 9, no. 2, pp. 60–66 (in Russian).

3. Chuprin V.A. Kontrol’ zhidkikh sred s pri¬ meneniem ul’trozvukovykh normal’nykh voln [Monitoring of liquid media using ultrasonic normal waves]. Moscow, LLC Publishing house SPEKTR, 2015, 218 p. (in Russian).

4. Hill C.R., Bamber J.C., ter Haar G.R. Ul’trazvuk v meditsine. Fizicheskie osnovy primeneniya [Ultrasound in medicine. Physical bases of application: Trans. with English]. Moscow, Fizmatlit Publ., 2008, 544 p. (in Russian).

5. Badmaev B.B., Damdinov B.B., Dembelova T.S. [Viscoelastic relaxation in fluids]. Bulletin of the Russian Academyof Sciences: Physics, 2015, vol. 79, no. 10, pp. 1301– 1305 (in Russian). doi: 10.3103/S1062873815100044

6. Badmaev B.B., Dembelova T.S., Makarova D.N., Gulgenov C.Z. [Shear elasticity and strength of the liquid structure by an example of diethylene glycol]. Technical Physics. The Russian Journal of Applied Physics, 2017, vol. 62, no. 1, pp. 14–17 (in Russian). doi: 10.1134/S1063784217010042

7. Esipov I.B., Zozulya O.M., Mironov M.A. [Slow nonlinearity kinetics of the viscoelastic properties of oil during shear vibrations]. Acoustical Physics, 2014, vol. 60, no. 2, pp. 169–174 (in Russian). doi: 10.1134/S1063771014020031

8. Mironov M.A., Shelomikhina I.A., Esipov I.B., Zozulya O.M. [Slow kinetics of viscoelastic properties of oil at low-frequency shear vibrations]. Acoustical Physics, 2012, vol. 58, no. 1, pp. 117–124 (in Russian). doi: 10.1134/S1063771014020031

9. Esipov I.B., Fokin A.V., Zozulya O.M. [Resonance method of measuring shear viscoelastic properties of liquid media based on excitation of torsional oscillations in tubes]. Acoustical Physics, 2010, vol. 56, no. 1, pp. 115–125 (in Russian). doi: 10.1134/S1063771010010161

10. Korobko E., Baev A., Bubulis A., Kuzmin V., Novikova Z., Novik E. The Peculiarities of Ultrasound Wave Propagation in Magnetorheological Fluid with Complex Dispersive Phase. Vibroengineering, 2015, vol. 6, pp. 326–329.

11. Sharapov V.M., Musiyenko M.P., Sharapova Е.V. P’ezoelektricheskie datchiki [Piezoelectric transducers]. Moscow, Technosphere Publ., 2006, 632 p. (in Russian).

12. Kolesnikov Yu.I., Boroda S.S. [On the determination of elastic constants of highly plastic materials]. Fizicheskaya mezomekhanika [Physical Mesomechanicsа], 2009, no. 12, pp. 121–126 (in Russian).