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THE CHOICE OF RELAXATION IN DESCRIBING MECHANICAL CHARACTERISTICS OF HIGH TEMPERATURE AREA OF DISSIPATIVE LOSS IN THE SPECTRUM OF INTERNAL FRICTION

https://doi.org/10.32362/2410-6593-2017-2-79-87

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Abstract

The analysis of experimental internal friction spectrum tgδ - f(T) shows that monocrystalline metallic materials possess the simplest spectrum. For those materials, dissipation of a part of the energy of external power impact exists in a form of internal friction background. The background increases slightly and monotonously at homologous temperatures θ < 0.2 ÷ 0.4, and it increases exponentially at θ ˃ 0.4. Taking into consideration the fact that monocrystalline systems may contain defects in the form of disturbance, and the concentration of point defects related to implantation atoms is minimal, one can suppose that this monocrystalline system consists of one aggregate subsystem having flat defects. Different analytical functions, which are often used in describing the inelasticity phenomenon, were studied as relaxation cores for describing the inelastic response of such subsystem in the area of increasing relaxation background of dissipative loss. It is shown that Rabotnov’s, Rzhanitsin’s and Havriliak-Negami’s cores don’t satisfy the asymptotic conditions for the convergence of series with positive values of incoming characteristics. In this case they cannot be used as relaxation functions describing the response of the aggregative subsystem in the temperature range which is higher than homologous temperature 0.4. Description of the viscoelastic response of the high-temperature background internal friction and, accordingly, of the temperature-frequency change of shear modulus is possible only when using Maxwell’s or Kolrausсh’s function which transforms into Maxwell’s function only at a single value of fractionality parameter.

About the Authors

A. A. Valishin
Moscow Technological University (M.V. Lomonosov Institute of Fine Chemical Technologies)
Russian Federation

Dr.Sc. (Physics and Mathematics), Professor of the Chair of Higher and Applied Mathematics

86, Vernadskogo Pr., Moscow, 119571, Russia)



E. M. Kartashov
Moscow Technological University (M.V. Lomonosov Institute of Fine Chemical Technologies)
Russian Federation

Dr.Sc. (Physics and Mathematics), Professor of the Chair of Higher and Applied Mathematics

86, Vernadskogo Pr., Moscow 119571, Russia



A. A. Kukhtenkova
Moscow Technological University (M.V. Lomonosov Institute of Fine Chemical Technologies)
Russian Federation

Senior Lecturer of the Chair of Physics and Technical Mechanics

86, Vernadskogo Pr., Moscow, 119571, Russia



V. A. Lomovskoy
Moscow Technological University (M.V. Lomonosov Institute of Fine Chemical Technologies)
Russian Federation

Dr.Sc. (Physics and Mathematics), Professor of the Chair of Chemistry and Technology of Plastics and Polymer Composites

86, Vernadskogo Pr., Moscow, 119571, Russia



References

1. Valishin A.A., Gorshkov A.A., Lomovskoy V.A. Relaxation phenomena and their mechanisms in livermush glasses // Izvestiya RAN. Mekhanika tverdogo tela (Mechanics of Solids). 2011. № 2. P. 169–182. (in Russ.).

2. Gorshkov A.A., Lomovskoy V.A., Naimi E.K. On the nature of background of internal friction in polycrystalline palladium // Vestnik MITHT (Fine Chemical Technologies). 2009.V. 4. № 6. Р. 85–89. (in Russ.).

3. Korovaytseva E.A., Gorshkov A.A., Lomovskoy V.A. Dislocation contribution to the hysteretic internal friction at homologous temperatures below 0.2 // Izvestiya RAN. Mekhanika tverdogo tela (Mechanics of Solids). 2017. № 2. P. 80–92. (in Russ.)

4. Chadek I. Creep of metallic materials. Moscow: Mir, 1987. 302 p. (in Russ.)

5. Korovaytseva E.A., Pshenichnov S.G., Tarlakovskii D.V. Propagation of one-dimensional non- stationary waves in viscoelastic half space// Lobachevskii Journal of Mathematics. 2017. V. 38. № 5. P. 827–832.

6. Korovaytseva E.A., Pshenichnov S.G. The study of transient wave processes in linear viscoelastic bodies taking into account the continuous heterogeneity of the material // Problemy prochnosti i plastichnosti (Problems of Strength and Plasticity). 2016. V. 78. № 3. P. 262–270. (in Russ.)

7. Korovaytseva E.A. The influence of the parameters of kernels of relaxation on wave propagation in a viscoelastic layer // Abstracts of XI All-Russian School-Seminar. Rostov-on-Don: Southern Federal University Publ., 2016. 72 p. (in Russ.)


For citation:


Valishin A.A., Kartashov E.M., Kukhtenkova A.A., Lomovskoy V.A. THE CHOICE OF RELAXATION IN DESCRIBING MECHANICAL CHARACTERISTICS OF HIGH TEMPERATURE AREA OF DISSIPATIVE LOSS IN THE SPECTRUM OF INTERNAL FRICTION. Fine Chemical Technologies. 2017;12(5):79-87. (In Russ.) https://doi.org/10.32362/2410-6593-2017-2-79-87

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ISSN 2410-6593 (Print)
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