Sergey Kiyashko
Ul’yanova str. 46, Nighniy Novgorod, 603950, Russia
Institute of Applied Physics, Russian Academy of Sciences
Publications:
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Nazarov V. E., Kiyashko S. B.
Evolution of Pulse and Periodic Elastic Waves in Media with Quadratically-Bimodular Nonlinearity
2018, Vol. 14, no. 3, pp. 331-342
Abstract
On the basis of the elastic contact model of rough surfaces of solids, a quadraticallybimodular
equation of state for micro-inhomogeneous media containing cracks is derived.
A study is made of the propagation of elastic single unipolar pulse perturbations and bipolar
periodic waves in such media. Exact analytical solutions that describe the evolution of
initially triangular pulses and periodic sawtooth waves are obtained. A numerical and graphical
analysis of the solutions is also carried out.
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Nazarov V. E., Kiyashko S. B.
Saw-tooth waves in hysteretic media with a saturation of nonlinear losses
2015, Vol. 11, No. 4, pp. 647–655
Abstract
On the basis of experimental data of the study of amplitude-dependent internal friction phenomena in polycrystalline solids the inelastic hysteretic state equation with a saturation of nonlinear losses is proposed. Theoretical analysis of the asymmetric saw-tooth waves propagation in such media is carried out. The regularities (amplitude dependent losses and changes in the propagation velocity) are determined for the characteristics of nonlinear wave and its higher harmonic amplitudes. The graphical analysis of form of the wave and evolution of its spectral components is carried out.
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Nazarov V. E., Kiyashko S. B., Radostin A. V.
Self-similar waves in media with bimodular elastic nonlinearity and relaxation
2015, Vol. 11, No. 2, pp. 209-218
Abstract
The results of research of the propagation of longitudinal acoustic waves in media with bimodular elastic nonlinearity and relaxation are presented. Analytical exact solutions have been obtained for the profiles of asymmetrical stationary waves as well as self-similar pulses and periodical waves propagating without distortions in their form.
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Nazarov V. E., Kiyashko S. B.
Amplitude-dependent internal friction and harmonics generation in solids with histeretic nonlinearity
2014, Vol. 10, No. 3, pp. 297-307
Abstract
Theoretical and numerical study of nonlinear wave processes in media with hysteretic nonlinearity are carried out. The phenomena of amplitude-dependent damping as well as change of the propagation velocity of harmonic wave and its second and third harmonic generation are considered. It was shown that the hysteretic media possess nonlinear dispersion that become apparent in the difference between the phase velocities of strong harmonic pump wave and its weak high harmonics. The dispersion leads to both spatial beatings and non-monotonically rate of growth of an amplitude of high harmonic at the increase in amplitude of basic frequency wave.
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