Materials physics and mechanics

RAR RUS 159-164 ITMO University Rylkova

St.Petersburg, Russia

ITMO University Zhiglinsky

St.Petersburg, Russia

ITMO Univesity V.G. Dubrovskii

St.Petersburg, Russia

ITMO University Sokolova

St.Petersburg, Russia

Nucleation of islands with vertical or truncated corner facets in vapor-liquid-solid nanowires We develop a model for nucleation of islands in vapor-liquid-solid nanowires with either vertical or truncated corner facets. Under the assumption of two-dimensional geometry of the growing island, it is shown that the earlier energetic condition for the truncated edge at the growth interface is modified by chemical potential. Therefore, the islands may nucleate at the trijunction during growth even if the truncation is preferred at the no growth conditions on surface energetic grounds. This conclusion may be used as the first step for understanding the peculiar oscillatory behavior of the growth interface and the related crystal phases of III-V nanowires. 10.18720/MPM.4222019_1 nanowires vapor-liquid-solid growth nucleation truncation surface energy chemical potential contact angle https://mpm.spbstu.ru/article/2019.68.1/ MPM242_01_dubrovskii.pdf

RAR RUS 165-177 Institute of Electrophysics, Ural Branch of RAS Spirin

Ekaterinburg, Russia

Institute of Electrophysics, Ural Branch of RAS Volkov

Ekaterinburg, Russia

Institute of Electrophysics, Ural Branch of RAS Boltachev

Ekaterinburg, Russia

Institute of Electrophysics, Ural Branch of RAS Chingina

Ekaterinburg, Russia

Densification rate influence on nanopowder compactibility The paper concerns processes of high-speed compaction of nanosized powders. The processes of uniform and uniaxial compaction have been simulated by the granular dynamics method. Nanoparticles interaction, in addition to known contact laws, includes dispersive attraction, formation of a strong interparticle bonding as well as the forces caused by viscous stresses in the contact region. For different densification rates, the densification curves (pressure vs. density) have been calculated. Relaxation of the stresses after the compression stage has been analyzed. The densification curves analysis allows us to suggest the dependence of compaction pressure as a function of strain rate in the form of 1/8 p v ∝ . The rate dependence obtained has been applied for interpretation of experimental data concerning high-speed processes of magnetic pulsed compaction of nanopowders. 10.18720/MPM.4222019_2 nanosized powders granular dynamics method high-speed compaction https://mpm.spbstu.ru/article/2019.68.2/ MPM242_02_boltachev.pdf

RAR RUS 178-182 Institute of Problems of Mechanical Engineering, Russian Academy of Sciences Osipova

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 of Problems of Mechanical Engineering RAS Osipov A.V.

St.Petersburg, Russia

Mechanism of molecule migration of carbon and silicon monoxides in silicon carbide crystal The main processes occurring during the migration of molecules of carbon monoxide CO and silicon monoxide SiO gases through a layer of monocrystalline silicon carbide SiC of a cubic polytype have been described by the ab initio methods. This problem arises when a single-crystal SiC layer is grown by the method of coordinated substitution of atoms due to the chemical reaction of a crystalline silicon substrate with the CO gas. The reaction products are epitaxial SiC layer and SiO gas. It has been shown that CO and SiO molecules decompose into separate atoms in the SiC crystal. The Oxygen atoms migrate through interstices only in the [110] direction (activation energy is 2.6 eV). The Si and C atoms transit by the vacancy mechanism in the corresponding SiC sublattices with activation energies of 3.6 eV and 3.9 eV respectively (and also only in the [110] direction). 10.18720/MPM.4222019_3 silicon carbide epitaxy diffusion ab initio modelling https://mpm.spbstu.ru/article/2019.68.3/ MPM242_03_kukushkin.pdf

RAR RUS 183-190 Peter the Great St. Petersburg Polytechnic University Golubkov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Zisman

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Sokolov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Rudskoy Andrey

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Vasilyev

St.Petersburg, Russia

Peter the Great St. Peresburg Polytechnic University Sokolov

St.Petersburg, Russia

Artifacts of stress relaxation technique to fit recovery activation parameters for low carbon steels The paper compares model predictions of recovery kinetics of low carbon steels with activation parameters determined by various experimental techniques. It is concluded that the stress relaxation method overestimates the recovery rate because the creep of stressed specimens is ignored. To avoid such errors, it is recommended to use an alternative method of double loading. The more realistic (lesser) rate of recovery with the related activation parameters complies with independent data of mechanical tests. 10.18720/MPM.4222019_4 steels recovery modeling stress relaxati https://mpm.spbstu.ru/article/2019.68.4/ MPM242_04_vasilyev.pdf

RAR RUS 191-197 Moscow Aviation Institute (National Research University) Zemskov

Moscow, Russia

Lobachevsky State University of Nizhni Novgorod Igumnov

Nizhni Novgorod, Russia

Lomonosov Moscow State University Tarlakovskiy

Moscow, Russia

Bulk Green's functions in one-dimensional unsteady problems of elastic diffusion We consider a one-dimensional unsteady problem of elasticity with diffusion and preset unsteady volumetric disturbances. The mathematical model is based on a local equilibrium model of elastic diffusion. The solution is sought in integral form. The bulk Green's functions are found via Laplace transform and Fourier transform for unbounded medium, sine and cosine transform for semi-bounded medium, Fourier's series for bounded medium. 10.18720/MPM.4222019_5 elastic diffusion unsteady problems Green's functions integral transformations https://mpm.spbstu.ru/article/2019.68.5/ MPM242_05_igumnov.pdf

RAR RUS 198-203 ITMO University Panov Dmitrii

St.Petersburg, Russia

ITMO University Shirshneva-Vaschenko

St.Petersburg, Russia

Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of RAS Gafarova

Kazan, Russia

Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of RAS Eremina

Kazan, Russia

F-1445-2014 7202768874 0000-0003-3738-408X ITMO University Romanov Alexey alexey.romanov@niuitmo.ru

St.Petersburg, Russia

ITMO University V.E. Bougrov

St.Petersburg, Russia

ITMO University Shirshnev

St.Petersburg, Russia

ITMO University Spiridonov Vladislav

St.Petersburg, Russia

The influence of gamma rays radiation on optically induced luminescence of copper-containing potassium-lithium-borate glass The paper presents the results of potassium-lithium-borate glass containing copper ions investigations. The glass was irradiated by 1.25 MeV gamma rays. The dose of radiation was 360 Gy. The exciting of the irradiated glass at 360 nm led to the long-wavelength photoluminescence band shift from 635 nm to 671 nm in comparison with non-irradiated glass. A new luminescence band at 685 nm also appeared for excitation wavelength 405 nm in the irradiated glass. It has been assumed that the luminescence band in glass at 671 nm – 685 nm corresponds to the luminescence of copper ions in the modified environment of the first coordination sphere. Copper-containing luminescent structures in borate glass with the luminescence maximum at 671-685 nm have been obtained for the first time. For the detailed study of these luminescent centers properties, thorough study of the structural variations in the gamma rays irradiated glass is required. 10.18720/MPM.4222019_6 gamma ray radiation cluster copper borate glass photoluminescence https://mpm.spbstu.ru/article/2019.68.6/ MPM242_06_shirshnev.pdf

RAR RUS 204-210 Sampoerna University Aamer

Indonesia

Universitas Pertamina Hastuty

Indonesia

Universitas Pendidikan Indonesia Nandiyanto

Bandung, Indonesia

Universitas Pendidikan Indonesia Abdullah

Indonesia

Sampoerna University Sunnardianto

Indonesia

Sampoerna University Triawan

Indonesia

Boron and nitrogen dopant atoms precise tuning (increment and reduction) of charge-transfer rates in hydrogenated graphene Graphene is a new remarkable material for diverse applications, especially when grapheme is interacted with hydrogen. The charge-transfer rates (CTR) from hydrogen to graphene is substantial to determine the electronic properties. A new approach to increase and decreases the charge-transfer from hydrogen to graphene is proposed. By using density functional theory calculation method, the effect of B and N doping on the CTR of hydrogenated graphene is investigated. The results found that both of dopants (B and N) had opposite effect on the CTR of hydrogenated graphene. B doping increased CTR, while N doping decreased CTR from hydrogen to graphene. The research finding may provide a promising rule for quantitatively tuning and or controlling of CTR in hydrogenation graphene by atom dopant, which is potential importance for their use in electrochemical and energyrelated application. 10.18720/MPM.4222019_7 charge-transfer rates (CTR) graphene hydrogenation coverage dopant https://mpm.spbstu.ru/article/2019.68.7/ MPM242_07_sunnardianto.pdf

RAR RUS 211-223 Menoufia University Aish

Egypt

The structural transformation and mechanical strength OF Ni, Ti nanowires and Nitinol alloys at various vacancy rates: molecular dynamic study using Cleri-Rosato potential A many-body interatomic potential was used for Nickel (Ni) crystal with facecentered cubic (FCC) lattice and Titanium (Ti) with hexagonal close-packed (HCP) lattice and Nitinol alloys within the second-moment approximation. The tight-binding model (the Cleri and Rosato potentials) was employed to carry out three dimensional molecular dynamics simulations upon application of uniaxial tension at nanoscale of studied materials, which contained various vacancy rates. We performed molecular dynamics (MD) simulations to study the yield mechanisms in Ni and Ti nanowires and Nitinol alloys. The coupled effects of various shapes, sizes, and locations of vacancy defects on the mechanical strength and structural deformation of nanowires are presented. The formation energies of vacancy defects are also evaluated. It was found that as the number of vacancies increases, the yield stress decreases. The results showed that breaking time changes with the increase in number of vacancy. To understand the effects of the vacancies on the mechanical properties of Ni and Ti nanowires and Nitinol alloys, tensile and fatigue tests are simulated. 10.18720/MPM.4222019_8 many-body Nitinol alloys vacancy defects https://mpm.spbstu.ru/article/2019.68.8/ MPM242_08_aish.pdf

RAR RUS 224-233 Manipal University Jaipur Pathak

India

Manipal University Jaipur Srivastava

India

Manipal University Jaipur Dikshit

Jaipur, India

Manipal University Jaipur Nair

India

Investigation of mechanical properties of graphene reinforced epoxy nanocomposite using molecular dynamics Graphene is a two-dimensional hexagonal type of carbon allotropes in the form of a sheet. It is a one atom thick sheet of carbon atoms, which has extraordinary thermal, mechanical, electronic and electrical properties. In the present research, a molecular dynamic study has been done to investigate the mechanical properties of graphene reinforced epoxy nanocomposite. A single layer of graphene sheet has been randomly reinforced into the epoxy matrix at 5%, 10%, 15% and 20% weight percentages. A dense amorphous cell is created using the Forcite module of Material Studio software and simulation is performed. Young's modulus is predicted at varying strain rate from 0-1. Results have revealed that Young's modulus increases with increase in reinforcement quantity. Moreover, graphene reinforced epoxy nanocomposite exhibits better properties than CNT reinforced nanocomposites. 10.18720/MPM.4222019_9 atomistic model epoxy graphene molecular dynamics Young's modulus https://mpm.spbstu.ru/article/2019.68.9/ MPM242_09_dikshit.pdf

RAR RUS 234-241 Manipal University Jaipur Pathak

India

Manipal University Jaipur Khurana

India

Manipal University Jaipur Srivastava

India

Manipal University Jaipur Dikshit

Jaipur, India

A molecular dynamics study of the buckling behaviour of graphene-reinforced aluminum nanocomposite plate In this study, effects of aspect ratio and perforation on the buckling response of graphene nanosheet (GNS)-embedded aluminum (Al) nanocomposite plate are studied using molecular dynamics (MD) simulations. The periodic system of GS-Al nanocomposite plate is built and simulated using molecular dynamics (MD) based software LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). Embedded atom method (EAM) and Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) potentials are employed to model the interactions between the atoms of Al and carbon atoms, respectively. It is observed that the buckling strength of square GNS-Al nanocomposite plate deteriorates drastically due to perforation and the same is also true for plates of higher aspect ratio. 10.18720/MPM.4222019_10 molecular dynamics nanocomposites graphene buckling plate https://mpm.spbstu.ru/article/2019.68.10/ MPM242_10_srivastava.pdf

RAR RUS 242-255 Southern Federal University Oganesyan

Rostov-on-Don, Russia

National Kaohsiung University of Science and Technology Chao

Kaohsiung, Taiwan

National Kaohsiung University of Science and Technology Liu

Kaohsiung, Taiwan

Southern Federal University Soloviev

Rostov-on-Don, Russia

Southern Federal University Chebanenko

Rostov-on-Don, Russia

Applied theory for electro-elastic plates with non-homogeneous polarization Non-uniformly polarized piezoceramic materials can be used in effective energy harvesting devices. Axisymmetric and plane models of electric elastic bodies were studied using applied theory and finite element method (FEM). Applied theory for devices made of parts with longitudinal and transverse polarization was developed. It was based on bending of electric elastic plates models. Numerical experiments for FEM models were performed in ACELAN package. Applied theory of second order vibrations was introduced. 10.18720/MPM.4222019_11 functionally graded material (FGM) prescribed temperature design optimization residual stresses minimization https://mpm.spbstu.ru/article/2019.68.11/ MPM242_11_soloviev.pdf

RAR RUS 256-264 Lobachevsky State University of Nizhni Novgorod Boev

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Igumnov

Nizhni Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Markov

Nizhni Novgorod, Russia

Boundary element time-harmonic analysis of 3D linear piezoelectric solids In this work, a boundary element method (BEM) is applied for time-harmonic analysis of three-dimensional linear piezoelectric solids. Coupled frequency domain boundary value problems of the linear theory of piezoelectricity are considered assuming zero initial conditions, in the absence of the body forces and free electric charges. The elastic and electric variables are combined into the extended vectors and tensors. Proposed boundary element approach employs regularized weakly singular frequency domain boundary integral equations (BIEs) for the extended displacements. A standard collocation procedure for the mixed boundary elements is used. Integral expressions of the three-dimensional frequency domain dynamic piezoelectric fundamental solutions are employed. Results of the boundary-element analysis of a test problem are provided to validate the proposed BEM formulation. 10.18720/MPM.4222019_12 piezoelectricity boundary element method time-harmonic analysis fundamental solutions https://mpm.spbstu.ru/article/2019.68.12/ MPM242_12_igumnov.pdf