Materials physics and mechanics

RAR RUS 691-698 Lobachevsky State University of Nizhni Novgorod Lamzin

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Bragov

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Lomunov

Nizhni Novgorod, Russia

Saint Petersburg State University Konstantinov

St.Petersburg, Russia

Università dell'Aquila dell'Isola

Italy

Analysis of the dynamic behavior of sand-lime and ceramic bricks The results of dynamic tests on building brick samples were analyzed using the incubation time fracture criterion. The strength and time properties of sand-lime brick and ceramic brick were under study. The tests were carried out using the classical Kolsky method and its modification - dynamic splitting. Strain rates under compression reached 2.5·103 MPa/s while stress rates under tension reached 3.5·102 GPa/s. It is noted that the strain rate affects the strength and time properties of the materials under study. The parameters of the incubation time fracture criterion were determined on the basis of the experimental deformation diagrams of material in axes stress versus time. Herewith, nonlinear nature of the loading branch of dynamic diagrams was taken into account. Both tested materials qualitatively showed the same change of the mechanical properties. 10.18720/MPM.4262019_1 dynamics brick split Hopkinson pressure bar splitting strain rate stress rate incubation time criterion https://mpm.spbstu.ru/article/2019.73.1/ MPM642_01_lamzin.pdf

RAR RUS 699-710 Indian Institute of Technology Roorkee Khan

Roorkee, India

Indian Institute of Technology Roorkee Iqbal

Roorkee, India

Institute for Problems of Mechanical Engineering of the RAS Bratov

St.Petersburg, Russia

Indian Institute of Technology Delhi Gupta

New Delhi, India

7005573911 St.Petersburg State University Morozov N.F.

St.Petersburg, Russia

A numerical study of ballistic behaviour of ceramic metallic bi-layer armor under impact load A 3D finite element model has been developed for studying the ballistic behaviour of bi-layer ceramic-metal target plates under the impact loads induced by the projectiles of different diameter to length ratios. The bi-layer target constituted of alumina 95, as front layer, backed by aluminium alloy 2024-T3 layer, has been impacted by steel 4340 blunt and ogival nosed projectiles of diameter to length ratios, 0.5 and 1.1. The constitutive behaviour of ceramic was modelled using the Johnson-Holmquist (JH-2) constitutive model while that of the metallic backing and the projectile using the Johnson-Cook (JC) material model. The range of incident velocity of the projectile was considered between 800-1000 m/s. The residual projectile velocity, damage induced in the target as well as the projectile, and the ballistic limit velocity (BLV) have been obtained for the different diameter to length ratios (of projectile). 10.18720/MPM.4262019_2 ballistic resistance ceramic-metal armor residual velocity finite element modelling https://mpm.spbstu.ru/article/2019.73.2/ MPM642_02_khan.pdf

RAR RUS 711-716 Gerasimov Lobachevsky State University of Nizhni Novgorod Igumnov

Nizhni Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Bragov

Nizhny Novgorod, Russia

Use of advanced materials in protection against high-velocity impact and explosion Numerical studies of the behavior of combined barriers consisting of solid and porous materials were carried out during high-speed impact on them with thin plates. It is shown that the introduction of plates of porous materials into the composition of combined barriers can significantly reduce the amplitude of compression waves and reduce the likelihood of spall damage. Comparison of the results of numerical modeling of high-speed impact interaction processes with the experimental results of other authors showed their good qualitative and quantitative agreement. 10.18720/MPM.4262019_3 high-velocity projectiles high-velocity explosion fracture multilayered targets https://mpm.spbstu.ru/article/2019.73.3/ MPM642_03_gerasimov.pdf

RAR RUS 717-730 University of Padova Settimi

Padova, Italy

Nosov Magnitogorsk State Technical University Chukin

Magnitogorsk, Russia

University of Padova Pezzato

Padova, Italy

University of Padova Gennari

Padova, Italy

University of Padova Brunelli

Padova, Italy

University of Padova Dabala

Padova, Italy

The impact of high heating rates on the austenitization process of 18NiCrMo5 steel This paper is focused on the study of the effect of high heating rates on austenite formation of 18NiCrMo5 steel. The prior martensitic microstructure was characterized with scanning electron microscopy and Vicker micro-hardness. Then dilatometric tests were performed at 12 different heating rates (in the range of 100 - 3000°C/s), to evaluate the critical points and the key factor governing the austenite formation with high heating rates. After these tests, the microstructures obtained were analyzed by optical microscopy, scanning and transmission electron microscopy. The Ac1 and Ac3 temperatures initially increased with heating rate, reaching a maximum and then decrased. The formation of austenite from martensite, with low heating rates, was diffusive, whereas with high heating rates, it took place through a displacive mechanism. Moreover, a higher dislocation density characterized the austenite obtained with high heating rates. 10.18720/MPM.4262019_4 low alloyed steel 18NiCrMo5 austenitization heating rate austenite martensite https://mpm.spbstu.ru/article/2019.73.4/ MPM642_04_settimi.pdf

RAR RUS 731-741 Bochvar Institute (VNIINM) Lukyanov

Moscow, Russia

Bochvar Institute (VNIINM) Polikarpova

Moscow, Russia

Research and Production Company "NANOÉLECTRO" Khlebova

Moscow, Russia

National Research Centre "Kurchatov Institute" Guryev

Moscow, Russia

Bochvar Institute (VNIINM) Belyakov

Moscow, Russia

Bochvar Institute (VNIINM) Pantsyrny

Moscow, Russia

The strengthening and the electrical resistivity of thermo-mechanical deformation processed Cu-Nb composite wires The effects of deformation and heat treatment on the electrical resistivity and the tensile strength of nanostructured Cu/Cu-18%Nb composite wires are studied. The correlated behavior of electrical resistivity and strength depending on the mode of thermo-mechanical processing is ascertained. The main mechanism of strengthening and increasing the electrical conductivity, associated with the reduction in the size of the structure, is considered. A good agreement is shown between the average distances between the Nb filament measured by SEM and extracted using the inversion of the resistivity size effect model. On the other hand, direct calculations of the strength value in accordance with the most common modern models are not consistent with experiments. In conclusion, the reasons for this discrepancy are discussed. 10.18720/MPM.4262019_5 Cu-Nb nanocomposute size effect strengthening intrinsic material scale https://mpm.spbstu.ru/article/2019.73.5/ MPM642_05_lukyanov.pdf

RAR RUS 742-748 Lobachevsky State University of Nizhni Novgorod Igumnov

Nizhni Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Metrikin

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Grigoryev

St.Petersburg, Russia

Dynamics of a frictional system, accounting for hereditary-type friction and the mobility of the vibration limiter Dynamics of a frictional system consisting of a rough body situated on a rough belt moving at a constant velocity is studied. The vibrations are limited by an elastic obstacle. The Coulomb-Hammonton dry friction characteristic is chosen, according to the hypothesis of Ishlinskiy and Kragelskiy, in the form of hereditary-type friction, where the coefficient of friction of relative rest (CFRR) is a monotone non-decreasing continuous functionof the time of relative rest at the previous analogous time interval. A mathematical model and the structure of its phase space are presented, as well as the equations of point maps of the Poincare surface and the results of studying the dynamic characteristics of the parameters of the system (velocity of the belt, type of the functional relation of CFRR, rigidity of the elastic obstacle, etc.). A software product has been developed which makes it possible to find complex periodic motion regimes, as well as to calculate bifurcation diagrams used for determining the main variations of the motion regime from periodic to chaotic (the period doubling scenario). 10.18720/MPM.4262019_6 frictional system vibrations elastic obstacle dry friction hypothesis of Ishlinskiy and Kragelskiy https://mpm.spbstu.ru/article/2019.73.6/ MPM642_06_igumnov.pdf

RAR RUS 749-757 Southern Federal University Andzhikovich

Rostov-on-Don, Russia

Southern Scientific Center of Russian Academy of Sciences Belyankova

Rostov-on-Don, Russia

Southern Scientific Center of Russian Academy of Sciences Kalinchuk

Rostov-on-Don, Russia

Southern Scientific Center of Russian Academy of Sciences Levi

Rostov-on-Don, Russia

Southern Federal University Levi

Rostov-on-Don, Russia

Southern Federal University Lyzhov

Rostov-on-Don, Russia

On wave field formation on the surface of piezoactive bodies with inhomogeneous coating Within the framework of a model for the piezoelectric structure with a coating made of a functionally graded material with a piecewise-continuous variation of properties, the problem of propagation of horizontally polarized shear surface waves was investigated. The influence of the polarization vector orientation and the nature of the coating inhomogeneity on the propagation of surface waves in an "acoustically homogeneous" structure was studied. 10.18720/MPM.4262019_7 piezoelectric structure inhomogeneous coating functionally graded piezoelectric material piecewise-continuous variation of properties surface acoustic wave (SAW) SH-waves Bleustein-Gulyaev waves https://mpm.spbstu.ru/article/2019.73.7/ MPM642_07_kalinchuk.pdf

RAR RUS 758-775 Institute of Problems of Mechanical Engineering RAS Meshcheryakov Yu.I.

St.Petersburg, Russia

Institute for Problems of Mechanical Engineering of the RAS Konovalov

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS Zhigacheva

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS Divakov

St.Petersburg, Russia

Central Research Institute of Constructional Materials "Prometei" Osokin

St.Petersburg, Russia

On the correlation between multiscale mechanisms of deformation in uniaxial dynamic straining and high velocity penetration In order to identify the successive stages of developing the hierarchy of multiscale mechanisms of dynamic straining, the shock-induced mesostructure formation is studied in combined experiments. Shock tests of two kinds of aluminum alloy, 1561 and 1565 alloys were conducted in parallel in two regimes of loading: (i) under uniaxial strain conditions and (ii) in high velocity penetration. Combination of loading regimes allows the correlation in formation of multiscale structure depending on strain rate and scheme of shock loading to be traced for both alloys. Formation of mesoscale-1 (1-10 μm) is initiated by the particle velocity pulsations resulted from space polarization of dislocation structure. In 1561 aluminum alloy the structural elements of mesoscale-2 (50-150 μm) are the result of grouping the microshears, whereas in 1565 alloy the mesostructure is the fault formations localized near the boundary of penetration cavern. The strength behavior of both kinds of aluminum alloy proves to be opposite - when resistance to penetration increases, the spall strength decreases. 10.18720/MPM.4262019_8 shock loading multiscale dynamic deformation high velocity penetration structural instability spallation https://mpm.spbstu.ru/article/2019.73.8/ MPM642_08_meshcheryakov.pdf

RAR RUS 776-783 Peter the Great St. Petersburg Polytechnic University Krasnitckii S.A.

St.Petersburg, Russia

ITMO University Smirnov A.M.

St.Petersburg, Russia

Ioffe Institute Mynbaev

St.Petersburg, Russia

University of Virginia Zhigilei

USA

0000-0003-0727-6352 Institute of Problems of Mechanical Engineering RAS Gutkin M. Yu.

St.Petersburg, Russia

Axial misfit stress relaxation in core-shell nanowires with hexagonal core via nucleation of rectangular prismatic dislocation loops A theoretical model of axial misfit stress relaxation in core-shell nanowires with hexagonal cross section of the core through the nucleation of prismatic dislocation loops is suggested. Different nucleation sites of the loops in core-shell nanowires are considered. The energy change caused by the loop nucleation is calculated. The critical condition for the onset of the loops is given and analyzed in detail. The most favorable sites in nanowires and the optimal loop shape are defined. 10.18720/MPM.4262019_9 core-shell nanowires misfit stress relaxation prismatic dislocation loops https://mpm.spbstu.ru/article/2019.73.9/ MPM642_09_krasnitckii.pdf

RAR RUS 784-796 Lobachevsky State University of Nizhni Novgorod Kondratev

Nizhny Novgorod, Russia

Perm National Research Polytechnic University Trusov

Perm, Russia

Multilevel models of inelastic deformation: determination of stable low angle boundaries pages The paper considers the method for determining stable low angle cell boundaries. The multilevel physical approach is applied to model inelastic deformation, using which shears are found for slip systems of the crystal. Based on these data, the density of two types of dislocation defects, which are stopped during deformation at crystallite boundaries, is introduced into consideration. The optimization problem is posed for finding sections of the boundary with reduced energy. The dependence of orientation of these sections relative to the crystallographic coordinate system is investigated. The results of solving the optimization problem and their analysis are presented. 10.18720/MPM.4262019_10 crystal plasticity crystal structure dislocation boundaries energy of low angle boundaries Reed-Shockley relation https://mpm.spbstu.ru/article/2019.73.10/ MPM642_10_kondratev.pdf

RAR RUS 797-801 ITMO Univesity Kremleva

St.Petersburg, Russia

Ioffe Institute Kirilenko

St.Petersburg, Russia

ITMO University Smirnova

St.Petersburg, Russia

ITMO University V.E. Bougrov

St.Petersburg, Russia

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

St.Petersburg, Russia

Structural characterization of bulk (AlXGa1-X)2O3 crystals grown by the ózochralski method Results of structural characterization of (AlxGa1-x)2O3 single crystals grown from the melt with Al content x up to 0.04 are presented. Bulk (AlxGa1-x)2O3 crystals were grown by exploring the Czochralski method [1]. Transmission electron microscopy (TEM) was used to investigate defect structure of the material with various composition, X-ray diffractometry was used to measure Al content x, to inspect crystallography of the growth facets and to characterize the structure quality of the samples. Possible types of defects were identified in the samples with various composition including single dislocations, cracks, and low-angle misorientation block boundaries. Measured full-width at half-maximum (FWHM) of rocking curves of 200" confirmed high quality of the grown crystals. 10.18720/MPM.4262019_11 Wide-bandgap semiconductor monoclinic gallium oxide defect dislocation stacking fault crack https://mpm.spbstu.ru/article/2019.73.11/ MPM642_11_kremleva.pdf

RAR RUS 802-807 Ioffe Institute Butenko

St.Petersburg, Russia

ITMO University Panov Dmitrii

St.Petersburg, Russia

ITMO Univesity Kremleva

St.Petersburg, Russia

ITMO University Zakgeim

St.Petersburg, Russia

Ioffe Institute Nashchekin

St.Petersburg, Russia

ITMO University Smirnova

St.Petersburg, Russia

ITMO University Bauman Dmitrii

St.Petersburg, 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

Czochralski grown (AlxGa1-x)2O3 crystals with variable Al content We propose a technuque of liquid-phase growth of (AlxGa1-x)2O3 crystals with variable and controlled Al content in them. When using the Czochralski growth process Ga2O3 melt was dosed by sapphire seed. By applying of the special growth zone and the regulating the process parameters, a series of crystal samples with Al content varying from 0.51 to 4.68 % at. was obtained. In addition to the standard setting of the geometry and weight of the crystals using the process parameters, with an increase of the Al content in the melt, it is possible to control the color, transparency and crystallinity of the fabricated samples. 10.18720/MPM.4262019_12 Gallium oxide sapphire seed crystal growth Czochralski process growth zone block structure materials characterization https://mpm.spbstu.ru/article/2019.73.12/ MPM642_12_butenko.pdf

RAR RUS 808-824 Saint-Petersburg Mining University Nosov

St.Petersburg, Russia

Saint-Petersburg Mining University Chaplin

St.Petersburg, Russia

Saint-Petersburg Mining University Gilyazetdinov

St.Petersburg, Russia

Saint-Petersburg Mining University Grigoriev

St.Petersburg, Russia

Saint-Petersburg Mining University Pavlenko

St.Petersburg, Russia

Micromechanics, nanophysics and non-destructive testing of the strength of structural materials Non-destructive testing of the strength of structural materials is currently based on the correlation between the results of laboratory tests of the strength of standard macro samples and the strength characteristics of the material in a real object. The heterogeneity of the strength properties of different zones of the material makes this correlation ambiguous, introducing uncertainty in the test results. The solution of the problem relates to the necessity of transition to the micro- and nano- control level that determines the strength, and to the applying of representative micro structural elements of the material and multipurpose physical nanoconstants as reference. The principles of selection of these elements and the method of assessing their strength characteristics are considered. The model proposed in the work has shown its effectiveness both in laboratory samples and in real industrial facilities. 10.18720/MPM.4262019_13 acoustic emission heterogeneous materials model of acoustic emission https://mpm.spbstu.ru/article/2019.73.13/ MPM642_13_nosov.pdf

RAR RUS 825-836 Ogarev Mordovia State University Cherkasov

Saransk, Russia

0000-0002-1069-2413 Ogarev Mordovia State University Avdonin

Saransk, Russia

0000-0003-4310-3379 Vyatka State University Yurkin

Kirov, Russia

Vyatka State University Suntsov

Kirov, Russia

Prediction of radiation shielding properties of self adhesive elastic coating Analytical definition of radiation shielding properties of polymeric materials is proposed. This method shows good convergence of theoretical calculations with experiment. Obtained results show, that to receive material with high protective properties it is necessary to add barite or tungsten filler in the amount of 50-70 % of the volume into the composition. Carried out researches show, that at energy of irradiation 59 keV materials with thickness of 2-3 mm are sufficient for radiation protection. At high energy of irradiation 661 keV half radiation minimizing is provided at thickness of 15 mm using oxide of lead and tungsten technical of 50 % in volume as filler and at thickness of 35 mm using barium sulphate of 50 % in volume as filler 10.18720/MPM.4262019_14 gamma shielding radiation protection mechanical properties ethylene propylene diene monomer (EPDM) metal oxide barite rubber composites prediction https://mpm.spbstu.ru/article/2019.73.14/ MPM642_14_cherkasov.pdf

RAR RUS 837-845 Peter the Great St. Petersburg Polytechnic University Krivtsov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Podolskaya

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Shubina

St.Petersburg, Russia

Asymptotics of a thermal wave in one-dimensional harmonic crystal An asymptotic representation is obtained at large times for the thermal wavefront propagating in a one-dimensional harmonic crystal. The propagation of thermal waves from a localized thermal perturbation and the transition zone between regions with different temperatures is considered. An explicit solution is given for a number of the simplest forms of the initial temperature distribution. It is shown that during the wave evolution, the wavefront smoothes, e.g., for a power-law dependence its degree increases by 1/2. 10.18720/MPM.4262019_15 low-dimensional materials discrete media thermal processes anomalous heat transfer harmonic crystal localized perturbations asymptotics wavefront https://mpm.spbstu.ru/article/2019.73.15/ MPM642_15_krivtsov.pdf

RAR RUS 846-858 Institute theoretical engineering him. A.A. Blagonravova The Russian academy of sciences (IMASH the Russian Academy of Science) Evdokimov

Moscow, Russia

Nonlinear elastic properties of rubber-cord shells of revolution The article presents the results of the study of nonlinear elastic properties of rubber-cord shells under static loading. A method for determining nonlinear properties is proposed. The approximations obtained in this case satisfactorily describe the results of the experiments. 10.18720/MPM.4262019_16 damping ability of the hysteresis loop coefficients of the nonlinearity stress tensor tangent matrix https://mpm.spbstu.ru/article/2019.73.16/ MPM642_16_evdokimov.pdf

RAR RUS 859-869 Peter the Great St. Petersburg Polytechnic University Papirovskiy

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Alekseev

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Tarasov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Borovkov A.I.

St.Petersburg, Russia

Development of numerical methods and virtual tests for cyclic durability by finite element method This paper deals with the issue of fatigue failure of materials. The process of generation of fatigue properties for the steel 08PS is described and obtained in the laboratory. The technique of conducting virtual tests for cyclic durability for vehicles is proposed. Virtual tests for cyclic durability by using the finite element method on the example of an off-road car body are performed. 10.18720/MPM.4262019_17 cyclic durability fatigue failure endurance limit FEM automotive industry https://mpm.spbstu.ru/article/2019.73.17/ MPM642_17_papirovskiy.pdf