Materials physics and mechanics

RAR RUS 1-6 113263 6701854079 0000-0001-9909-2950 Institute of Problems of Mechanical Engineering RAS Sheinerman Alexander

St.Petersburg, Russia

Effect of the specimen size on necking development in metals and alloys during superplastic deformation A model is proposed that describes the development of individual and multiple necks in superplastically deformed materials. Within the model, the examined samples have the form of round bars and are subjected to tensile superplastic deformation without strain hardening. It is demonstrated that neck development and necking-induced failure occur faster with a decrease in strain rate sensitivity and/or an increase in the fraction of the sample length occupied by necks. This means that high values of strain to failure observed in small specimens of superplastically deformed ultrafine-grained metals and alloys, where diffuse necking happens in the whole specimen, can be significantly reduced in larger specimens where the necking regions occupy only a small part of the sample. 10.18149/MPM.4612020_1 superplastic deformation necking ductility failure ultrafine-grained materials https://mpm.spbstu.ru/article/2020.79.1/ 1-A_G_-Sheinerman.pdf

RAR RUS 7-26 Punjabi University Lata

Patiala, Punjab, India

Punjabi University Kaur

Patiala, Punjab, India

Kurukshetra University Singh

India

Thermomechanical interactions due to time harmonic sources in a transversely isotropic magneto thermoelastic rotating solids in Lord-Shulman model The present research deals with the mathematical modelling of two dimensional transversely isotropic magneto thermoelastic initially stressed solid due to time-harmonic source with generalized Lord-Shulman (LS) theory of thermoelasticity. The Fourier transform has been used to find the solution to the problem. The expressions for the displacement components, stress components, and temperature distribution are obtained in the transformed domain. The effect of time-harmonic source is depicted graphically on the resulting quantities. 10.18149/MPM.4612020_2 transversely isotropic Magneto thermoelastic mechanical and thermal stresses time-harmonic source https://mpm.spbstu.ru/article/2020.79.2/ 2-Parveen-Lata%2C-Iqbal-Kaur%2C-Kulvinder-Singh.pdf

RAR RUS 27-41 Southern Federal University Vatulyan

Rostov-on-Don, Russia

Southern Federal University Nesterov

Rostov-on-Don, Russia

On the deformation of a composite rod in the framework of gradient thermoelasticity The gradient thermoelasticity problem for a composite rod based on the applied one-parameter model is investigated. To find the Cauchy stresses, the Vishik-Lyusternik asymptotic approach is used, taking into account the presence of boundary-layer solutions in the vicinity of the rods' boundaries and interface. A new dimensionless parameter equal to the ratio of the second rod length and the gradient parameter are introduced. Simplified formulas are constructed in order to find the distribution of the Cauchy stresses depending on the new parameter. After finding the Cauchy stresses distribution, moment stresses, total stresses, displacements, and deformations are further calculated. The dependence of the Cauchy stress jump on the ratio of the rods' physical characteristics and the scale parameter is investigated. The analysis of the results provided is performed. 10.18149/MPM.4612020_3 composite rod gradient model thermoelasticity Cauchy stresses moment stresses asymptotic approach boundary layer https://mpm.spbstu.ru/article/2020.79.3/ 3-A_O_-Vatulyan%2C-S_A_-Nesterov.pdf

RAR RUS 42-49 Ioffe Institute Timashov

St.Petersburg, Russia

Ioffe Institute Chikiryaka

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Pulnev

St.Petersburg, Russia

0000-0003-4205-3226 Ioffe Institute Guzilova L.I.

St.Petersburg, Russia

Ioffe Institute Nikolaev

St.Petersburg, Russia

Ioffe Institute Yakushev

St.Petersburg, Russia

Ioffe Institute Stepanov

St.Petersburg, Russia

Burst-like shape memory recovery and calorimetric effect in Cu-Al-Ni alloy single crystals at cyclic test Here we report on compressive stress-strain behavior, ordinary and burst-like shape memory (SM) strain recovery, and associated caloric effects in Cu – 14.02% wt. Al – 4.0% wt. Ni single crystals which have multiphase martensitic structure at room temperature. The effect of repetitive thermo-mechanical cycling on the recovery of the shape memory deformation is investigated. The stress-strain curves of the specimens are smooth in all tests. Immediately after quenching, crystals exhibited burst-like strain recovery accompanied by the jumping of the whole specimen in each deformation-recovery. After several days from quenching, crystals showed weaker jumping which was also reducing with each thermo-mechanical cycle. The average values of the integral thermal effect remained the same from cycle to cycle. Although the starting temperature of burst-like reverse martensitic transformation stochastically varied from cycle to cycle, it showed a general tendency to decrease with an increasing number of cycles until the burst-like effect disappears completely. The heating rate does not significantly affect the position of the DSC peak. Low temperature aging of the specimens resulted in the gradual weakening and disappearance of the burst-like strain recovery. Thus, thermal treatment and loading regimes should be optimized for high-cycle applications of Cu-Al-Ni alloys. 10.18149/MPM.4612020_4 shape memory alloys (SMA); strain recovery; martensitic phase transformation; differential scanning calorimetry (DSC) https://mpm.spbstu.ru/article/2020.79.4/ 4-Guzilova-et-al.pdf

RAR RUS 50-56 Ioffe Institute Priadko

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Pulnev

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Kovalev

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Ilin

St.Petersburg, Russia

Algorithm for positioning of rotary actuators based on shape memory Cu-Al-Ni tensile force elements This paper considers positioning algorithms for rotary actuators based on shape memory Cu-Al-Ni crystals. The actuator function scheme is provided. An algorithm for positioning of the actuator based on an actual rotary angle has been developed. Experimental results on the control algorithm and the actuator are presented. The functional characteristics of the actuator (rotation speed and positioning accuracy) are considered. 10.18149/MPM.4612020_5 shape memory effect Cu–Al–Ni single crystals cyclic rotary actuator positioning algorithms https://mpm.spbstu.ru/article/2020.79.5/ 5-A-Priadko%2C-S-Pulnev%2C-O-Kovalev%2C-I-Ilin.pdf

RAR RUS 57-63 Mechanical Engineering Research Institute, Russian Academy of Science Sarafanov

Nizhni Novgorod, Russia

The dynamic mechanism of low-temperature instability of plastic deformation in metals Under the assumption of structural softening of plastic deformation in metals, a solution of the system of equations for the ensemble of dislocations is obtained describing a running front for the dislocation density (soliton). Such dislocation charge is able to destroy deformation barriers and cause an athermal mechanism of the instability of the low-temperature plastic deformation. 10.18149/MPM.4612020_6 low-temperature deformation kinetic instability dynamic pile-up of dislocations https://mpm.spbstu.ru/article/2020.79.6/ 6-G_F_-Sarafanov.pdf

RAR RUS 64-69 Mechanical Engineering Research Institute, Russian Academy of Science Sarafanov

Nizhni Novgorod, Russia

Kozma Minin Nizhny Novgorod State Pedagogical University Shodin

Nizhny Novgorod, Russia

Autowave mechanism of localization of low-temperature plastic deformation The mechanism of localization of low-temperature plastic deformation is investigated within the framework of the thermal activation model. The localization mechanism is considered as a result of the autowave character of the stationary solution of a system of equations that describes both the processes of thermal conductivity and plastic deformation. It is established that the stationary solution of the initial problem is given by the wave fronts of switching waves of temperature and plastic deformation. It is shown that the considered autowave mechanism determines the process of localization of high-temperature areas of plastic deformation in the cross-section of the sample in the form of either a neck or separate deformation bands. 10.18149/MPM.4612020_7 deformation localization thermally activated plastic deformation low temperatures autowaves https://mpm.spbstu.ru/article/2020.79.7/ 7-G_F_-Sarafanov%2C-Yu_G_-Shodin.pdf

RAR RUS 70-87 Central Research Institute of Constructional Materials "Prometei" Osokin

St.Petersburg, Russia

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 Divakov

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS Zhigacheva

St.Petersburg, Russia

Investigation of multiscale mechanisms of dynamic deformation and fracture of 1565 aluminum alloy under plane collision and high-velocity penetration High strength 1565 aluminum alloy was tested within impact velocity range of 250-750 m/s in two schemes of shock loading: (i) under uniaxial strain conditions and (ii) in high-velocity penetration. The combination of load regimes allows the different stages of multiscale structure formation to be retraced. The intensity of macro-meso momentum exchange is found to be responsible for both resistance to spallation and high-velocity penetration. The overall impact velocity region is found to be subdivided by three sub-regions of different mechanisms of dynamic straining and scales. The strength behavior of material differs for different regions of impact velocities. Within impact velocity regions where the resistance to penetration increases, the spall strength decreases. The transition from one scale level to another is shown to be realized through the excitation of velocity oscillations at the mesoscale. 10.18149/MPM.4612020_8 aluminum alloy spallation high-velocity penetration multiscale deformation macro-meso momentum exchange velocity oscillations https://mpm.spbstu.ru/article/2020.79.8/ 8-Yu_I_-Meshcheryakov-et-al.pdf

RAR RUS 88-98 Lobachevsky State University of Nizhni Novgorod Bragov

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Igumnov

Nizhni Novgorod, Russia

Saint Petersburg State University Konstantinov

St.Petersburg, Russia

Lobachevsky State University of Nizhni Novgorod Lomunov

Nizhni Novgorod, Russia

Joint Stock Company "Afrikantov OKB Mechanical Engineering" Romanov

Nizhny Novgorod, Russia

Joint Stock Company "Afrikantov OKB Mechanical Engineering" Panov

Nizhny Novgorod, Russia

Joint Stock Company "Afrikantov OKB Mechanical Engineering" Samsonov

Nizhny Novgorod, Russia

Joint Stock Company "Afrikantov OKB Mechanical Engineering" Chirkin

Nizhny Novgorod, Russia

Study of the deformation and fracture of zirconium alloys under dynamic loading The main objective of the present work is the experimental and theoretical investigation of the mechanical properties of the zirconium alloys E110 and E635 in a wide range of strain rates (10-4÷3·103 с-1) and at different temperatures (20°С÷350°С). The strain rate and temperature dependencies of deformation diagrams and strength characteristics under tension and compression have been received using the experimental study. The investigated materials have shown sensitivity to strain rate and temperature. Experimental data have been used to identify some LS-DYNA's material models. 10.18149/MPM.4612020_9 experimental investigation strain rate model nuclear energy dynamics temperature flow stress plastic strain ultimate strain https://mpm.spbstu.ru/article/2020.79.9/ 9-A_M_-Bragov-et-al.pdf

RAR RUS 99-114 Institut Teknologi Bandung Budiman

Bandung, Indonesia

Sampoerna University Triawan

Indonesia

Universitas Pendidikan Indonesia Nandiyanto

Bandung, Indonesia

Sampoerna University Suryani

Jakarta, Indonesia

Universitas Pendidikan Indonesia Fiandini

Bandung, Indonesia

The influence of turmeric microparticles amount on the mechanical and biodegradation properties of cornstarch-based bioplastic material: from bioplastic literature review to experiments The purpose of this study was to investigate the effects of turmeric microparticles amount on the mechanical and biodegradation properties of cornstarch-based bioplastic material. To produce the bioplastics, several steps were done sequentially: (1) dissolving a mixture of cornstarch, glycerol, and acetic acid in aqueous solution; (2) adding turmeric microparticles with a specific amount (i.e., 0.50; 0.75; 1.00; 1.50% (w/w)); (3) homogenizing the mixture at temperature of 60ºC; (4) molding process; and (5) drying process to get a solid bioplastic. Experimental results showed that the addition of turmeric microparticles could change the bioplastics strength as well as its biodegradability, while too much amount of turmeric may result in high strength but low biodegradability. 10.18149/MPM.4612020_10 bioplastics biodegradation cornstarch turmeric mechanical properties https://mpm.spbstu.ru/article/2020.79.10/ 10-F_-Triawan%2C-A_B_D_-Nandiyanto%2C-I_O_-Suryan1%2C-M_-Fiandini%2C-B_-A_-Budiman.pdf

RAR RUS 115-121 Institute of Problems of Mechanical Engineering RAS Bobylev S.V.

St.Petersburg, Russia

Simulation of inverse Hall-Petch relation in nanocrystalline ceramics by discrete dislocation dynamics method A theoretical model of plastic deformation of nanocrystalline ceramics in the region of small grain sizes is proposed. In the framework of the model, deformation is described as the combined action of grain boundary sliding and emission of lattice dislocations from triple junctions of grain boundaries. Using the method of discrete dislocation dynamics we obtained an inverse Hall-Petch relation, which qualitatively coincides with the experimentally measured dependences of microhardness in nanocrystalline ceramics with extremely small grain sizes. 10.18149/MPM.4612020_11 discrete dislocation dynamics inverse Hall-Petch relation ceramics yield stress hardness https://mpm.spbstu.ru/article/2020.79.11/ 11-S_V_-Bobylev(1).pdf

RAR RUS 122-131 7005573911 St.Petersburg State University Morozov N.F.

St.Petersburg, Russia

Saint Petersburg State University Smirnov

St.Petersburg, Russia

Saint Petersburg State University E.G. Zemtsova

St.Petersburg, Russia

Saint Petersburg State University Yurchuk

St.Petersburg, Russia

St Petersburg State University Sidorov

St.Petersburg, Russia

Institute for Problems of Mechanical Engineering of the RAS Semenov

St.Petersburg, Russia

Synthesis of metallic composite based on iron frame and SiC nanostructures and its strength properties The article discusses a new approach to the synthesis of metallic composite materials based on nanostructuring of a metal frame (on the example of iron) by SiC nanostructures (10-50 nm). Optimal conditions are established for the nano-SiC coating on the porous Fe surface during sequential chemisorption of Cl2Si(CH3)2 and CH4 molecules from the gas phase. The resulting composite possesses enhanced strength in comparison with the best steel samples although the residual porosity (up to 5%) of Fe matrix is still preserved after pressing. 10.18149/MPM.4612020_12 composite metallic framework iron disperse phase SiC ultimate strength https://mpm.spbstu.ru/article/2020.79.12/ 12-B_N_-Semenov%2C-N_F_-Morozov-et-al.pdf

REP RUS 132-138 Kalasalingam Academy of Research and Education Muthugopal

India

Kalasalingam Academy of Research and Education Jeganathan

India

Kalasalingam Academy of Research and Education Pragadeesh

India

Kalasalingam Academy of Research and Education Arun Prasath

India

Kalasalingam Academy of Research and Education Arumugaprabu

India

Kalasalingam University Amuthakkannan

Krishnankoil, India

Indian Institute of Technology Madras Naresh

Chennai

Quasi static and flexural mechanical property evaluation of basalt/flax reinforced composites Basalt fiber is one of the best reinforcing materials and satisfies all the needs of a composite material. Flax is predominately used natural fiber which has better mechanical and sudden load shock-absorbing properties. The general-purpose polyester resin in one an excellent binding agent which equally distributes the load along the direction of applications. To understand the mechanical properties of the natural and synthetic fiber of these flax/basalt fiber combinations is essential to reduce the usage of synthetic fibers. In this paper, the maximum tensile strength was found on the combination of pure 10 layers of basalt and it was about 185MPa. The maximum flexural strength absorption was seen in the combination of 10 layers of basalt fiber composite about 190MPa. The maximum impact energy was absorbed by composite D, the alternative layers of basalt and flax fiber composite. SEM analysis shows with matrix cracking, and fiber twist was seen, this is because of the improper mixing of the fiber and matrix shows this type of internal failure, the fiber pulls out and blow holes in between the fiber and matrix also seen in the composites. 10.18149/MPM.4612020_13 basalt fiber flax fiber polyester resin quasi-static mechanical behavior tensile test impact test https://mpm.spbstu.ru/article/2020.79.13/ 13-Arun-Prasath-et-al.pdf

RAR RUS 139-148 Rostov State Transport University Kolesnikov

Rostov-on-Don, Russia

Rostov State Transport University Suvorova

Rostov-on-Don, Russia

Rostov State Transport University Belyak

Rostov-on-Don, Russia

Modeling antifriction properties of composite based on dynamic contact problem for a heterogeneous foundation Based on the solution of the dynamic contact problem of vibration of a rigid punch on a heterogeneous half-space, taking into account friction in the contact area, the tribological properties of an oil-filled composite material with a microstructure are modeled. The microstructure of the base is taken into account in the framework of the Biot-Frenkel model. The boundary-value problem is reduced to the integral equation, its approximate solution is constructed, which describes contact stresses, tangential displacements. The dependencies of the friction forces on the microstructure of the composite, the viscosity of the fluid filling the pores, and the degree of phase interaction are investigated. 10.18149/MPM.4612020_14 dynamic contact problem with friction oil-filled composite https://mpm.spbstu.ru/article/2020.79.14/ 14-V_I_-Kolesnikov%2C-T_V_-Suvorova%2C-O_A_-Belyak.pdf

RAR RUS 149-167 Peter the Great St. Petersburg Polytechnic University Melker A.I.

St.Petersburg, Russia

Nuclear geometry: from nitrogen to neon The nuclear geometry was developed by analogy with the fullerene geometry. On the basis of this geometric approach, it was possible to design the structure of nitrogen, oxygen, fluorine and neon isomers and their isotopes, which can be obtained by means of nuclear synthesis. The most stable nuclei can be classed into two groups: basic nuclei having equal number of protons and neutrons and isotopes having one or two more neutrons. The latter ensure their mechanical stability with respect to shear stresses, sending their electron to the external coat of mail created by the basic nuclei. 10.18149/MPM.4612020_15 fluorine carbon graph representation isomer isotope neon nitrogen nuclear electron nuclear geometry nuclear reaction nuclear synthesis oxygen https://mpm.spbstu.ru/article/2020.79.15/ 15-Alexander-I_-Melker.pdf

RAR RUS 168-181 Peter the Great St. Petersburg Polytechnic University Melker A.I.

St.Petersburg, Russia

Nuclear geometry: sodium, magnesium, aluminum The nuclear geometry has been developed by analogy with the fullerene geometry. On the basis of this geometric approach, it was possible to design the structure of sodium, magnesium and aluminum isomers and their isotopes, which can be obtained by means of nuclear synthesis. The most stable nuclei can be classed into two groups: basic nuclei having equal number of protons and neutrons and isotopes having one or two more neutrons. The latter ensure their mechanical stability with respect to shear stresses, sending their electron to the coat of mail created by the basic nuclei. 10.18149/MPM.4612020_16 aluminum graph representation isomer isotope magnesium nuclear electron nuclear geometry nuclear reaction sodium https://mpm.spbstu.ru/article/2020.79.16/ 16-Alexander-I_-Melker.pdf

RAR RUS 182-190 CIAM Vasilyev

Moscow, Russia

BMSTU Selivanov

Moscow, Russia

CIAM Shibaev

Moscow, Russia

Material behaviour during a complex stress test of thin-walled, cylindrical single-crystal specimens The von Mises and Hill yield criteria are commonly used when the stress-strain state of parts under complex loading conditions is calculated. However, those yield criteria are not suitable in some materials and do not reliably describe the inelastic behavior of the material under complex stress conditions. The development of a simple and accurate criterion of plastic flow is relevant. This paper presents the results of the yield criterion development for a single crystal nickel-based superalloy (ZhS32) based on the systematization of experimental data. Various types of stress state were realized during the experiment: tension, compression, torsion, as well as combinations of tension-torsion, compression-torsion. 10.18149/MPM.4612020_17 single-crystal crystallographic orientation anisotropy stress-strain state plasticity yield strength ultimate strength complex stress test https://mpm.spbstu.ru/article/2020.79.17/ 17-Boris-Vasilyev-Alexander-Selivanov-Sergey-Shibaev.pdf

RAR RUS 191-201 Shirak State University after M. Nalbandyan Sargsyan

Gyumri, Armenia

Stability of the micropolar thin round plate In this paper, a thin round plate of isotropic micropolar elastic material is considered, in which the elastic deflections are comparable with their thickness, and small in relation to the basic size, also both the angles of rotation of the normal elements to the middle plane before deformation and their free rotations are small. Thus, the strain tensor and tensor of bending-torsion takes into account not only linear but also the nonlinear terms in the gradients of displacement and rotation. The stability problem is solved in the case when the solid round plate is hinge supported along the contour and is under the action of radial compressive forces. After solving the obtained boundary value problem, the critical value of the external force is determined. The critical force of the micropolar problem is compared with the value of the classical solution. The important properties of micropolar material are established. 10.18149/MPM.4612020_18 micropolar elastic thin round plate curvilinear coordinates geometrically nonlinear applied model stability https://mpm.spbstu.ru/article/2020.79.18/ 18-A_H_-Sargsyan.pdf

RAR RUS 202-206 Ioffe Institute Sovtus

St.Petersburg, Russia

Ioffe Institute Mynbaev

St.Petersburg, Russia

Analytical description of quantum effects at current filamentation in chalcogenide glasses Quantum effects occurring during current filamentation in a chalcogenide glass are considered. Under the conditions considered, the current filament appears as a set of concentric tubes with different temperatures. In every tube, the electron has a specific wave function and a specific energy level. The radii of the tubes appear to be proportional to natural numbers n. The dependence of maximal temperature on the electrical field is obtained. The Schroedinger equation is reduced to the first order differential equation. The type of energy of an electron at the tube is close to exciton energy dependence. The potential energy of an electron is described with the first order polynom of temperature. The temperature distribution in the filament is shown as an interference of the electron. 10.18149/MPM.4612020_19 chalcogenide glasses; current filament; quantization https://mpm.spbstu.ru/article/2020.79.19/ 19-N_-Sovtus%2C-K_-Mynbaev.pdf

RAR RUS 207-220 National Research University "Moscow Aviation Institute" Strizhius

Moscow, Russia

Estimation of delamination growth rate in quasi-isotropic composites using the stiffness degradation model The main features of physical modeling of the growth of delaminations under cyclic tension of quasi-isotropic composite materials are considered using the model of decreasing the initial stiffness. It is noted that these features are significantly different from the provisions of the classical mechanics of interlayer fracture of composite materials. As a definite development of this direction, based on the use of the stiffness degradation model, a number of new relationships have been proposed, which make it possible to more accurately than the existing models to carry out calculated estimates of the growth rate of delamination. Verification of the proposed relations is carried out on the example of calculated estimates of the growth rate of delaminations in a quasi-isotropic CFRP laminate XAS/914 [45/90/-45/0]s. 10.18149/MPM.4612020_20 quasi-isotropic composite materials delamination cyclic tension degradation of stiffness growth rate of delamination https://mpm.spbstu.ru/article/2020.79.20/ 20-Strizhius.pdf