Materials physics and mechanics

RAR RUS 1-8 Karunya University Selvamani

India

Influence of thermo-piezoelectric field in a circular bar subjected to thermal loading due to laser pulse The influence of thermo-piezoelectric field in a circular bar subjected to thermal loading due to non-Gaussian laser pulse is discussed using linear theory of thermoelasticity. The equations of motion of the rod are formulated using the constitutive equations of a thermopiezoelectric material. Displacement potential functions are introduced to uncouple the equations of motion, heat conduction and charge equation. The frequency equation of the system is developed under the assumption of stress free, thermal and electrically shorted boundary conditions. The numerical calculations are carried out for the material PZT-5A and the computed stress, strain and temperature distribution are plotted as the dispersion curves and their physical characteristics are discussed for longitudinal and flexural (symmetric and antisymmetric) modes. piezoelectric rod; non-Gaussian laser pulse; thermal vibration; sensors; actuators https://mpm.spbstu.ru/article/2016.47.1/ MPM127_01_selvamani.pdf

RAR RUS 9-21 Panjab University Gupta

India

Panjab University Ahuja

India

59122315900 0000-0002-1572-2108 Kurukshetra University Kumar Rajneesh

Kurukshetra, India

Panjab University Wanchoo

India

On the hydromagnetic stability of a horizontal nanofluid layer with Hall currents The paper investigates the hydromagnetic stability of a horizontal nanofluid layer heated from below in the presence of Hall currents. In addition to the Brownian motion and thermophoretic forces, Lorentz force is introduced due to high magnetic field. Boussinesq’sapproximation is used to linearize the hydromagnetic equations and perturbation equations are analysed using method of normal modes and one term Galerkin approximation. The critical Rayleigh number and critical wave number for alumina-water nanofluid and copper-water nanofluid for different values of Chandrasekhar number and Hall parameter are found. Copper-water nanofluid is found to be far less stable than alumina-water nanofluid. The mode of heat transfer is through stationary convection for the present configuration. Effect of Hall currents is to quicken the onset of convection whereas that of magnetic field is to postpone it. nanofluid layer; Hall currents; hydromagnetic stability https://mpm.spbstu.ru/article/2016.47.2/ MPM127_02_gupta.pdf

RAR RUS 22-31 59122315900 0000-0002-1572-2108 Kurukshetra University Kumar Rajneesh

Kurukshetra, India

36169811300 0000-0002-0873-0046 Maharishi Markandeshwar University Kaushal

Haryana, India

Seth Jai Parkash Mukand Lal Institute of Engineering & Technology Reen

Haryana, India

Deenbandhu Chhotu Ram University Garg

Murthal (Sonipat), India

Deformation due to various sources in transversely isotropic thermoelastic material without energy dissipation and with two-temperature A general solution to the field equations of a transversely isotropic thermoelastic without energy dissipation and with two temperatures due to various sources has been obtained in the transformed domain using the Laplace and Fourier transforms. As an application, concentrated or distributed sources have been taken to illustrate the utility of the approach. The transformed solutions are inverted numerically using a numerical inversion technique. The result in the form displacement components, conductive temperature and stress components are obtained numerically and illustrated graphically for particular model. Some special cases of interest are also discussed for investigation. thermoelasticity; without energy dissipation; two-temperature; integral transforms; Laplace and Fourier transforms; concentrated and distributed sources https://mpm.spbstu.ru/article/2016.47.3/ MPM127_03_kaushal.pdf

RAR RUS 32-41 Institute of Problems of Mechanical Engineering RAS Aero

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering, Russian Academy of Sciences Korzhenevskii

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS Bulygin

St.Petersburg, Russia

The theory of plane deformation under the conditions of austenite-martensite transformation The analytical approach of a plane deformation of a plate experiencing austenitemartensite transformation is developed. The thin plate is considered which energy takes into account the appearance of the martensitic transformation besides large elastic strains. The former generates specific microstrains that destroy compactness and translational order of the original perfect crystal. Making use of the previously analyzed model of a complex lattice consisting from two mutually penetrating sublattices enable us to describe both the long and the short possible destruction of the crystal order. The conservation of the polar momentum that is coupled with a mutual shift of the sublattices is taken into account. A possible cardinal reconstruction of the whole lattice and in particular the change of the number of the nearest atomic neighbours is allowed in contrast to the classical Landau theory of phase transitions. It is relaxing of the latter restriction in our theory that enables us to apply it to crystals experiencing martensitic transformations. the theory of plane deformation; austenitic-martensitic transformations; specific microstrains; two mutually penetrating crystal sublattices. https://mpm.spbstu.ru/article/2016.47.4/ MPM127_04_aero.pdf

RAR RUS 42-52 Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

113263 6701854079 0000-0001-9909-2950 Institute of Problems of Mechanical Engineering RAS Sheinerman Alexander

St.Petersburg, Russia

7003559440 0000-0003-2192-0386 Institute for Problems of Mechanical Engineering RAS Skiba Nikolai nikolay.skiba@gmail.com

St. Petersburg, Russia

Micromechanics of twinning and detwinning processes in nanocrystalline and ultrafine-grained metals We provide a brief overview of theoretical models that address twinning and detwinning processes in nanocrystalline and ultrafine-grained metals. In particular, we discuss and compare special mechanisms for formation of nanoscale deformation twins at grain boundaries (GBs) in nanocrystalline and ultrafine-grained materials. The twinning mechanisms represent (i) the successive events of partial dislocation emission from GBs; (ii) the cooperative emission of partial dislocations from GBs; and (iii) the multiplane nanoscale shear generated at GBs. In addition, we examine the detwinning mechanism in ultrafinegrained nanotwinned metals through stress-driven migration of incoherent boundaries of nanoscale twins. We demonstrate that detwinning of ultrathin twins can occur at very low stresses, while detwinning of thicker twins requires high applied stresses, and these theoretically revealed conclusions are well consistent with recent experimental data. ultrafine-grained metals; plastic deformation; nanotwinned metals; twinning; detwinning; defects; modeling https://mpm.spbstu.ru/article/2016.47.5/ MPM127_05_ovidko.pdf

RAR RUS 53-59 Altai State Technical University Poletaev Gennady M.

Barnaul, Russia

I.I. Polzunov Altai State Technical University Starostenkov

Barnaul, Russia

Institute for Metals Superplasticity Problems Dmitriev

Ufa, Russia

Interatomic potentials in the systems Pd-H and Ni-H Interatomic potentials are developed to model hydrogen impurities in Pd and Ni. The Н-Н potentials are constructed taking into account the results of ab initio simulations reported in the literature. The Pd-H and Ni-H potentials are fitted to the experimental data such as the absorption energy, the activation energy of over-barrier diffusion of H in metals, and the H-vacancy binding energy. interatomic potential; molecular dynamics; metal; hydrogen; absorption energy; diffusion activation energy https://mpm.spbstu.ru/article/2016.47.6/ MPM127_06_poletaev.pdf

REP RUS 60-67 Peter the Great St. Petersburg Polytechnic University Kochnev

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

Mechanical characteristics of graphene sheets containing 5-5-5-9 defects Molecular dynamics is exploited to examine mechanical characteristics (stress-strain dependence, tensile strength, and maximum elastic strain) of graphene sheets containing 5-5- 5-9 defects. Each such a defect represents a tetravacancy (localized group of four vacancies) associated with .pentagon-pentagon-pentagon-enneagon. atomic configuration in hexagonal crystal lattice of graphene. We revealed that the tensile strength of graphene sheets dramatically degrades (by 5-7 times) due to the presence of 5-5-5-9 defects in graphene, as compared to the tensile strength of defect-free graphene. Also, results of our computer model indicate that the mechanical characteristics of graphene sheets containing 5-5-5-9 defects are highly sensitive to geometry of their mechanical loading. graphene; defects; mechanical characteristics. https://mpm.spbstu.ru/article/2016.47.7/ MPM127_07_kochnev.pdf

RAR RUS 68-73 Ioffe Institute Bryushinin

St.Petersburg, Russia

Ioffe Institute Sokolov

St.Petersburg, Russia

Ioffe Institute Pisarev

St.Petersburg, Russia

Moscow Power Engineering Institute Balbashov

Moscow, Russia

Material characterization of a β-Ga2O3 crystal We report the excitation of the non-steady-state photo-electromotive force in a monoclinic gallium oxide crystal. The crystal grown in an excess of oxygen is insulating and very transparent for a visible light, but this, however, does not prevent us from the formation of dynamic space-charge gratings and observation of the photo-EMF signal at λ=532 nm. The induced ac current is studied for the cases of zero external electric fields. The dependencies of the signal amplitude versus the frequency of phase modulation, light intensity, spatial frequency are measured. The photoconductivity and diffusion length of electrons are estimated for the chosen light wavelength. wide-bandgap semiconductors; non-steady-state photo-electromotive force https://mpm.spbstu.ru/article/2016.47.8/ MPM127_08_sokolov.pdf

RAR RUS 74-78 Peter the Great St. Petersburg Polytechnic University Polukhin

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Mikhailovskiy

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Rybalko

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Solov'ev

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Odnoblyudov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Gubenko

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Livshits

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Firsov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Kirsyaev

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Efremov

St.Petersburg, Russia

ITMO University V.E. Bougrov

St.Petersburg, Russia

Simulation operation regimes of passive mode-locked laser based on InGaAlAs/InGaAs/InP heterostructures We propose a model of passive mode-locking laser diode based on quantum wells. Numerical results for InGaAlAs/InGaAs/InP heterostructure with 4 quantum wells in active region are presented. The dynamics of the transition to mode-locking has been investigated. It has been shown that mode-locking occurs approximately within 30 ns. The pulse duration was amounted to 2 ps, average output power - to 9.4 mW. The appearance of the second harmonic radiation in the resonator is connected to the insufficient absorber relaxation rate passive mode-locked laser; InGaAlAs/InGaAs/InP heterostructures; simulation operation regimes https://mpm.spbstu.ru/article/2016.47.9/ MPM127_09_polukhin.pdf

RAR RUS 79-89 Auckland University of Technology Pasang

New Zealand

Tarbiat Modares University Ramezani

Tehran, Iran

University of Notre Dame Prygoski

Indiana, USA

National Aerospace Laboratory NLR Wanhill

Emmeloord, The Netherlands

Airframes & Engine Division, Platform Sciences Laboratory, Defence Science & Technology Organisation (DSTO) Byrnes

Melbourne, Australia

Akita University Kamiya

Japan

kita University Hospital Tanaka

Akita, Japan

Fatigue of commercially pure titanium dental implants Failure of two commercially pure titanium dental implants was analysed. The implants fractured at the abutments after only three years use. One abutment failed at the junction of the threaded and unthreaded areas, the other failed within the threaded area. Both failures were by reversed bending fatigue, whereby fatigue cracks began from relatively coarse machining marks on the abutments. The final fracture areas were less than 10 % of the total fracture surfaces, indicating that the abutments had not been abnormally loaded. However, bone resorption would have increased the abutment bending stresses by causing an increased moment arm of the acting forces and misalignment of the abutments in the maxilla. The effect of misalignment was investigated by finite element modelling, which showed that even a slight misalignment could double the bending stresses. This unanticipated large effect, combined with the coarse machining marks, explains the premature failure of the implants. dental implant; fatigue; finite element simulation; metallography; titanium https://mpm.spbstu.ru/article/2016.47.10/ MPM127_10_ramezani.pdf

RAR RUS 79-89 Auckland University of Technology Pasang

New Zealand

Tarbiat Modares University Ramezani

Tehran, Iran

University of Notre Dame Prygoski

Indiana, USA

National Aerospace Laboratory NLR Wanhill

Emmeloord, The Netherlands

Airframes & Engine Division, Platform Sciences Laboratory, Defence Science & Technology Organisation (DSTO) Byrnes

Melbourne, Australia

Akita University Kamiya

Japan

kita University Hospital Tanaka

Akita, Japan

RAR RUS 90-97 Institute Silicate Chemistry of Russian Academy of Science Konakov V.G.

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Kurapova

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Arutyunyan A.R.

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Lomakin

St.Petersburg, Russia

Institute Silicate Chemistry of Russian Academy of Science Solovyeva E.N.

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Novik

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

Structure and mechanical characteristics of Ni - 1 WT.% Y2O3-92ZrO2 nanocomposites fabricated by powder metallurgy method Ni - 1 wt.% Y2O3-92ZrO (YSZ) composite is fabricated by powder metallurgy technique with subsequent annealing at 1250 °С. Both the presence of ceramic nanopowder inclusions in the composite and identity of the compositions specifying the final phase and the initial mixture are revealed by energy dispersive analysis. With scanning electron microscopy, the microstructure of the composite is examined, and its typical grain size is estimated. The mechanical tests of the composite are performed addressing both tension of flat specimens and compression of cylindrical specimens. The optimal techniques for the further cyclic tests of Ni - 1 wt.% YSZ are proposed according to the standardized tests (GOST 25.502-79). powder metallurgy method; Ni - 1 wt.% Y2O3-92ZrO2 nanocomposite; microstructure; mechanical tests https://mpm.spbstu.ru/article/2016.47.12/ MPM127_11_konakov.pdf

RAR RUS 98-107 Institute for Problems in Mechanical Engineering of Russian Academy of Sciences Telyatnik

St.Petersburg, Russia

Numerical approximations of Green.s functions for elastic anisotropic media by spherical harmonics, interaction energies of point defects Fundamental solutions of elastostatics for infinite anisotropic media are obtained by numerical integration, and also by the finite element method for bounded sphere. These solutions are presented in the form of mean-squared approximation by the series of spherical harmonics Ylm up to the order l = 10 (look for Online Support Data, pdf) as exemplified by the materials of different elastic symmetry: isotropic (concrete), cubic (Si), hexagonal (AlN), orthorhombic (MgSiO3 in perovskite phase), tetragonal with 6 or 7 independent elastic constants (ZrSiO4 and CaWO4 respectively), trigonal with 6 or 7 constants (Al2O3 and dolomite), monoclinic (gypsum), triclinic (Al2SiO5). Using obtained Green's functions for each crystal, the energy of elastic interaction of a pair of point defects has been plotted as a function of angles of their mutual orientation. elastic anisotropic media; Green.s functions; spherical harmonics; numerical approximations; point defects https://mpm.spbstu.ru/article/2016.47.13/ MPM127_12_telyatnik.pdf

RAR RUS 108-112 Zhengzhou University Li

Zhengzhou, China

Zhengzhou University Tie

Zhengzhou, China

Zhengzhou University Li

Zhengzhou, China

Analysis of the opening problem of the composite materials structures with boundary integral equation method Almost all the structures in the fields of practical engineering are applied with various kinds of holes, for example, there are manholes in the plane wings. When the structures are subject to loads, the stress concentration will appear around the holes, which will reduce both the static strength and the fatigue strength. In this paper, in view of the orthotropic plate with manholes, the calculation model was established based on complex function, and the analytic solution of hole-edge stress of orthotropic plate with complex hole shape was figured out. By virtue of mapping function, the parametric equation which accurately describes hole boundary was obtained. As a result, based on the established model, under different fiber array, the holeedge stress of composite material plate with wing manholes was calculated, and stress distributions around the holes under two kinds of fiber array were compared. Thus this study provides theoretical reference for design of flywheel. exact analytic solutions of stress on hole edge; orthotropic; opening problems; different fiber arrays; wing manhole; elastic solution https://mpm.spbstu.ru/article/2016.47.14/ MPM127_13_li.pdf

RAR RUS 113-117 Belarussian National Technical University, V.V. Barkaline

Minsk, Belarus

Belarusian National Technical University Chashynski

Minsk, Belarus

Simulation of electromechanical properties of ordered carbon nanotube arrays Phenomenological approach to frequency domain electric properties of ordered carbon nanotube arrays is presented accounting mechanical resonances of nanotubes. It is shown numerically that resonances could lead to strong frequency dependence of dielectric permittivity of arrays and UHF devices using them. ordered carbon nanotube array; electromechanical properties; simulation https://mpm.spbstu.ru/article/2016.47.15/ MPM127_14_barkaline.pdf

RAR RUS 118-121 Belarusian National Technical University Grigorenko

Minsk, Belarus

Belarussian National Technical University, V.V. Barkaline

Minsk, Belarus

Computer generation of the models of localized defects of carbon nanotubes and graphene The research of formation principles of topological defects in graphene layers and carbon nanotubes was carried out in atomistic model approach. The models of defective graphene structures were developed and optimized with molecular mechanics algorithms. carbon nanotubes; graphene; defects; computer generation https://mpm.spbstu.ru/article/2016.47.16/ MPM127_15_grigorenko.pdf