Materials physics and mechanics

RAR RUS 101-106 FSBEI HPE “Kh.M. Berbekov Kabardino-Balkarian State University” Mikitaev

Nalchik, Russia

FSBEI HPE “Kh.M. Berbekov Kabardino-Balkarian State University” Kozlov

Nalchik, Russia

The percolation model of nanocomposites polymer/carbon nanotubes reinforcement The principally new percolation model for description of the extreme dependence of elasticity modulus on nanofiller contents for nanocomposites polymer/carbon nanotubes was proposed. The indicated model takes into account nanocomposites reinforcing component change from interfacial regions up to carbon nanotubes network at the last percolation threshold. From the mathematical point of view for the dependence of elasticity modulus on carbon nanotubes contents description the general percolation relationship is used with critical index change at percolation threshold. nanocomposite; carbon nanotubes; percolation; elasticity modulus; ring-like structures https://mpm.spbstu.ru/article/2015.39.1/ MPM222_01_mikitaev.pdf

RAR RUS 107-117 MM University Sharma

Mullana, Ambala, Haryana, India

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

Kurukshetra, India

Punjabi University Lata

Patiala, Punjab, India

Disturbance due to inclined load in transversely isotropic thermoelastic medium with two temperatures and without energy dissipation The present investigation is concerned with the two dimensional deformation in a homogeneous, transversely isotropic thermoelastic solids with two temperatures in context of Green-Naghdi theory of type-II as a result of an inclined load. The inclined load is assumed to be linear combination of normal load and tangential load. Laplace and Fourier transforms are employed to solve the problem. The components of displacements, stresses and conductive temperature distribution so obtained in the physical domain are computed numerically. Effect of two temperatures is depicted graphically on the resulting quantities. transversely isotropic thermoelastic; Laplace transform; Fourier transform; concentrated force; distributed sources https://mpm.spbstu.ru/article/2015.39.2/ MPM222_02_kumar.pdf

RAR RUS 118-124 Karpagam University Shanmughasundaram

India

Statistical analysis on influence of heat treatment, load and velocity on the dry sliding wear behavior of Aluminium alloy 7075 In this paper, the influence of the heat treatment, load and sliding velocity on the wear loss of the Al alloy 7075 was evaluated using a pin-on-disc wear testing rig. Dry sliding wear tests were conducted for three different loads (5, 10, and 15 N) for three different velocities (0.8, 1.6, and 2.4 m/s). Taguchi and Analysis of Variance (ANOVA) techniques were employed to investigate the influence of parameters on the wear loss of Al alloy. Multiple linear regression models were also developed to predict the wear loss of alloys. It was observed that the wear increased with increasing load and sliding velocity. The results showed that T6 Al - alloy aged for 6 hrs exhibited better wear resistance compared to as - cast alloy and T6 alloy aged for 2 hrs. The results reveal that the normal load is the most influencing the wear resistance followed by the heat treatment and sliding velocity. The worn surface morphology was investigated by Scanning Electron Microscope (SEM). Al alloy 7075; dry sliding wear; Taguchi; ANOVA; heat treatment https://mpm.spbstu.ru/article/2015.39.3/ MPM222_03_shanmughasundaram.pdf

RAR RUS 118-124 University of California Samaei

USA

Iran University of Science and Technology Aliha

Tehran, Iran

Texas A&M University, Mirsayar

USA

Frequency analysis of a graphene sheet embedded in an elastic medium with consideration of small scale The effect of length scale on the vibration response of a single-layer graphene sheet embedded in an elastic medium is studied using nonlocal Mindlin plate theory. The elastic medium is modeled using both Winkler-type and Pasternak-type elastic foundations. An explicit solution is derived for the natural frequencies of the graphene sheet. Through the analytical solution it is found that the vibration response of graphene sheet concerning the length scale effects considerably different from the results obtained by the classical theories. In comparison with the classical plate theory, the nonlocal model showed that the natural frequency of the graphene sheet decreases for smaller lengths of graphene sheet, higher aspect ratios, greater values of nonlocal parameter and stiffer elastic foundations. graphene sheets; frequency; nonlocal elasticity; elastic medium https://mpm.spbstu.ru/article/2015.39.4/ MPM222_04_samaei.pdf

RAR RUS 136-156 Institute of Problems of Mechanical Engineering RAS Meshcheryakov Yu.I.

St.Petersburg, Russia

Saint Petersburg State University Khantuleva

St.Petersburg, Russia

Nonlocal mechanics of nonequilibrium shock-wave processes Results of experimental research on shock loading of solid materials demonstrate that the revealed dependences of waveforms and threshold of the structure instability on strain-rate, target thickness and state of the material structure cannot be described in the framework of the conventional continuum mechanics. New concept of shock-wave processes in condensed matter is proposed on base of nonlocal theory of nonequilibrium transport which allowed a transition from the elastic medium reaction to the hydrodynamic one depending on the rate and duration of the loading. A new mathematical model of elastic-plastic wave is constructed to describe the elastic precursor relaxation and the plastic front formation taking into account the changing оf material properties during the wave propagation. Analysis of experimental waveforms shows that for the shock-induced processes it is incorrect a priori to divide the components of stress and strain into elastic and plastic parts. The model allowed accounting for the inertial medium properties under short-duration loading and selforganization of new internal structures. shock waves; elastic precursor; plastic front; velocity variation; velocity defect; nonlocal model; transport processes https://mpm.spbstu.ru/article/2015.39.5/ MPM222_05_meshcheryakov.pdf

RAR RUS 157-169 Siberian State Industrial University Sarychev

Novokuznetsk, Russia

Siberian State Industrial University Nevskii

Novokuznetsk, Russia

Siberian State Industrial University Gromov

Novokuznetsk, Russia

The theoretical analysis of stress-strain state of materials with gradient structure The analysis of the stress-strain state of a material with a hardened layer obtained when exposed to concentrated energy fluxes, using matrix algorithms of the theory of elasticity by contact loading is implemented. The dependences of the normal and tangential stresses from the longitudinal dimensions of the sample in the transition zone between the hardened layer and the matrix are found. It is shown that the resulting stresses are compressive and do not exceed the tensile strength of materials. Lame's equations; matrix of transition; gradient structure; stress-strain state https://mpm.spbstu.ru/article/2015.39.6/ MPM222

RAR RUS 170-175 Kazan Federal University Shibakov

Kazan, Russia

Kazan Federal University Pankratov

Kazan, Russia

Kazan Federal University Andreev

Kazan, Russia

Kazan Federal University Andreeva

Kazan, Russia

The heterogeneity of the stress-strain state during severe plastic deformation by multiple extrusion A method of obtaining a hardened semi-intensive plastic deformation by extrusion is considered. The results of process simulation at different stages of extrusion are given. Conclusions are drawn about the applicability of the simulation results to obtain the axisymmetric products. severe plastic deformation (SPD); multiple extrusion; simulation; QForm 2D/3D; hardening; nanostructure; algorithm; blank; blank production; aluminium; accumulation of deformations; rod blanks; semi-finished https://mpm.spbstu.ru/article/2015.39.7/ MPM222_07_andreev.pdf

RAR RUS 176-182 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 neighbors 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; thin plate; austenite-martensite transformation https://mpm.spbstu.ru/article/2015.39.8/ MPM222_08_aero.pdf

RAR RUS 183-190 Institute for Problems of Mechanical Engineering of the RAS Benemanskaya

St.Petersburg, Russia

Institute for Problems of Mechanical Engineering of the RAS Dementev

St.Petersburg, Russia

P-4505-2016 7006034020 0000-0002-2973-8645 Institute of Problems of Mechanical Engineering RAS Kukushkin S.A. sergey,a.kukushkin@gmail.com

St.Petersburg, Russia

Institute for Problems of Mechanical Engineering of the RAS Lapushkin

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS Osipov A.V.

St.Petersburg, Russia

Helmholtz Zentrum Berlin fur Materialen und Energie Senkovskiy

Berlin, Germany

Institute for Problems of Mechanical Engineering of the RAS Timoshnev

St.Petersburg, Russia

Photoemission study of nano SiC epitaxial layers synthesized by a new method of the atom substitution in Si crystal lattice Electronic structure of the SiC epitaxial nanolayer synthesized by a new method of the atom substitution in silicon crystal lattice has been first studied in situ in an ultrahigh vacuum using synchrotron radiation photoemission spectroscopy with photon energies in the range of 60-400 eV. Features of photoemission from the valence band and from both the Si 2p, C 1s core levels were revealed and shown to be provided by the high-quality clean SiC(111) sample with Si-rich surface. The photoemission from a surface state extending from the valence band maximum into gap was found. Three surface-related components of Si 2p core level were found. Only one surface component of the C 1s core level was found that indicates on one position of C atoms near the surface. The results support the full Si adlayer structure model of the SiC (111) surface that is characterized by Si- double layers, Si-dimers and Si adatoms. silicon carbide; electronic structure; photoemission spectroscopy https://mpm.spbstu.ru/article/2015.39.9/ MPM222_09_kukushkin.pdf

RAR RUS 191-199 Peter the Great St. Petersburg Polytechnic University Rudskoy Andrey

St.Petersburg, Russia

T-5749-2017 6602123579 0000-0002-2102-1076 Peter the Great St. Petersburg Polytechnic University Kodzhaspirov Georgij kodjaspirov@spbstu.ru

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Kitaeva D.A.

St.Petersburg, Russia

Kyrgyz-Russian Slavic University Rudaev

Bishkek, Kyrgyzstan

VŠB – Technical University of Ostrava Kliber

Ostrava – Poruba, Czech. Republic

To the problem of the cylindrical product with a bottom forming process optimization under superplasticity condition It is considered the problem of the cylindrical product with a bottom forming process optimization under aluminium alloys superplasticity condition. It is shown that the volume of the superplastic deformation zone increases with approaching to the middle of the thermal interval effect demonstration. The formation of the maximum amount of this area contributes to the formation of the fine-grained structure in the walls of the product. superplasticity numerical simulation aluminum alloys fine-grained structure dynamic recrystallization https://mpm.spbstu.ru/article/2015.39.10/ MPM222_10_kodzhaspirov.pdf