Materials physics and mechanics

RAR RUS 133-145 Lobachevsky State University of Nizhni Novgorod Bragov

Nizhny Novgorod, Russia

Saint Petersburg State University Konstantinov

St.Petersburg, Russia

Military University of Technology Kruszka

Warsaw, Poland

Lobachevsky State University of Nizhni Novgorod Lomunov

Nizhni Novgorod, Russia

Behavior of stainless steel at high strain rates and elevated temperatures. Experiment and mathematical modelling On the example of 1810 stainless steel, the results of modern experimental and theoretical analysis of high-speed deformation and destruction of a viscoplastic material are presented. The analysis used the results of basic experiments based on the Kolsky method under compression and tension, as a result of which stress-strain curves were obtained at different strain rates and temperatures. On the basis of this data, the parameters of the Johnson-Cook model with different versions of the strain-rate multiplier are obtained. For verification of the selected model, in the framework of the Kolsky method, two schemes were proposed for dynamic indentation and diametrical compression of cylindrical specimens. Comparison of the numerical simulation and experimental results allowed us to estimate the reliability of the model. Using the plane-wave shock experiment and the VISAR interferometer, the yield strength and spall strength of stainless steel at the strain rate of 105 s-1 were determined. This data, together with the results of experiments, using the Kolsky method under tension, allowed us to construct the dependence of the limiting strength characteristics of stainless steel in the range of strain rates of 103 - 105 s-1. 10.18720/MPM.4022018_1 Kolsky method plane wave experiment material model identification verification spall strength stainless steel https://mpm.spbstu.ru/article/2018.66.1/ MPM240_01_bragov.pdf

RAR RUS 146-151 Lobachevsky State University of Nizhni Novgorod Bragov

Nizhny Novgorod, Russia

Saint Petersburg State University Konstantinov

St.Petersburg, Russia

Lobachevsky State University of Nizhni Novgorod Lomunov

Nizhni Novgorod, Russia

Experimental study of the influence of the type of stress-strain state on the dynamic compressibility of spheroplastic By using a set-up that implements the Kolsky method, dynamic tests were carried out at compression under conditions of uniaxial stress state and uniaxial strain of the spheroplastics in the initial state and aged. Dynamic diagrams were obtained for these modes. In the uniaxial stress state, the strength of the material was determined. In the uniaxial deformation, the lateral expansion ratio and shear strength were determined. 10.18720/MPM.4022018_2 high-speed deformation experiments the Kolsky method spheroplastic dynamic diagrams https://mpm.spbstu.ru/article/2018.66.2/ MPM240_02_bragov.pdf

RAR RUS 152-157 FSBEI HPE “Kh.M. Berbekov Kabardino-Balkarian State University” Kozlov

Nalchik, Russia

FSBEI HE “Kh.M. Berbekov Kabardino-Balkarian State University” Dolbin

Nalchik, Russia

The description of elastic modulus of nanocomposites polyurethane/graphene within the frameworks of modified blends rule For description of elastic modulus of nanocomposites polyurethane/graphene the modified mixtures rule was proposed, which takes into consideration two factors. First, this rule assumes, that in polymer nanocomposites interfacial regions are the same reinforcing element of their structure, as actually nanofiller. Secondly, real, but not nominal, characteristics values of nanocomposite components were used. This allows the quantitative description of elastic modulus of the considered nanocomposites exactly enough. Reaching of percolation threshold of graphene platelets results to the essential enhancement of elastic modulus for both structure components and nanocomposite as a whole. 10.18720/MPM.4022018_3 mixtures rule nanocomposite graphene elastic modulus interfacial regions https://mpm.spbstu.ru/article/2018.66.3/ MPM240_03_kozlov.pdf

RAR RUS 158-171 Alexandria University Youssef

Alexandria, Egypt

Arab Academy for Science and Technology El-Bary

Alexandria, Egypt

Theory of hyperbolic two-temperature generalized thermoelasticity Youssef improved the generalized thermoelasticity base on two distinct temperatures; the conductive temperature and the thermodynamics temperature which coincide together when the heat supply vanishes [1, 2]. This theory has one paradox, where it offers an infinite speed of thermal wave propagation. So, this work assuming a new consideration of the two types of temperature which depends upon the acceleration of the conductive and the thermal temperature. This work introduces the proof of the uniqueness of the solution, moreover, one dimensional numerical application. According to the numerical result this new model of thermoelasticity offers finite speed of thermal wave and mechanical wave propagation. 10.18720/MPM.4022018_4 elasticity thermoelasticity hyperbolic two-temperature finite speed wave propagation https://mpm.spbstu.ru/article/2018.66.4/ MPM240_04_youssef.pdf

RAR RUS 172-180 Peter the Great St. Petersburg Polytechnic University Podolskaya

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Krivtsov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Tsvetkov

St.Petersburg, Russia

Anomalous heat transfer in one-dimensional diatomic harmonic crystal The work is devoted to description of unsteady thermal processes in lowdimensional materials. One-dimensional harmonic crystals with alternating masses and stiffnesses are considered. Analytical solution demonstrates the ballistic nature of heat propagation, which is confirmed by numerical simulations based on the particle dynamics method. It is shown that temperature distribution propagates as two consecutive thermal fronts with finite speed, and its initial shape is preserved. 10.18720/MPM.4022018_5 mathematical modeling low-dimensional materials discrete media thermal processes heat transfer lattice dynamics harmonic crystal polyatomic lattice https://mpm.spbstu.ru/article/2018.66.5/ MPM240_05_podolskaya.pdf

RAR RUS 181-186 Peter the Great St. Petersburg Polytechnic University Markov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Linkov

St.Petersburg, Russia

Correspondence principle for simulation hydraulic fractures by using pseudo 3D model The original pseudo three-dimensional (P3D) model is extended to an arbitrary stress contrast on the basis of the correspondence principle suggested. The principle employs the similarity between solutions to plain-strain elasticity problems for (i) the crack, corresponding to the central cross-sections of the P3D model, and (ii) the crack of the Khristianovich-Geertsma-de Klerk (KGD) model, when the sizes and average openings of the cracks are the same. This suggests using the propagation speeds of the KGD problem for assigning the speed of the height growth of the P3D model. This approach is applicable in all the cases when the KGD problem may be accurately solved; specifically, when accounting for an arbitrary stress contrast. 10.18720/MPM.4022018_6 hydraulic fracturing pseudo three dimensional (P3D) model stress contrast https://mpm.spbstu.ru/article/2018.66.6/ MPM240_06_markov.pdf

RAR RUS 187-200 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

South Scientific Center of Russian Academy of Sciences Sheydakov

Rostov-on-Don, Russia

Higher-order model of prestressed isotropic medium for large initial deformations Within the theory of small deformations superposed on a finite one, a consistent linearization for the nonlinear equations of the mechanics of an originally isotropic elastic body in a neighborhood of some initial stress state is carried out in the Lagrange coordinate system. As the elastic potential for the originally isotropic body, we use the representation of the specific strain energy through the algebraic invariants of the Green-Lagrange strain tensor. The linearized constitutive relations and the equations of motion of the prestressed medium are derived that allow taking into account the nonlinear effects of the initial deformation on the elastic properties of the originally isotropic body. 10.18720/MPM.4022018_7 initial stress prestressed initial deformation elastic moduli of III orders elastic moduli of IV orders linearized theory large initial deformations elastic potential of IV orders https://mpm.spbstu.ru/article/2018.66.7/ MPM240_07_belyankova.pdf

RAR RUS 201-211 Institute for Metals Superplasticity Problems of Russian Academy of Sciences Musabirov

Ufa, Russia

Institute for Metals Superplasticity Problems of Russian Academy of Sciences Safarov

Ufa, Russia

Institute for Metals Superplasticity Problems of the Russian Academy of Sciences Galeyev

Ufa, Russia

Institute for Metals Superplasticity Problems of Russian Academy of Sciences Abdullina

Ufa, Russia

Bashkir State University Gaifullin

Ufa, Russia

Institute for Metals Superplasticity Problems of Russian Academy of Sciences Afonichev

Ufa, Russia

Kotelnikov Institute of Radio Engineering and Electronics of Russian Academy of Sciences Koledov

Moscow, Russia

Institute for Metals Superplasticity Problems of Russian Academy of Sciences Mulyukov

ufa

Comparison of influence forging and extrusion on microstructure of heusler alloys The results of investigation of the microstructure of two polycrystalline Ni-Mn-Ga alloys subjected to thermo-mechanical treatment by multiple isothermal forging and extrusion are presented. Alloy forging at a temperature of 680°C and 700°C leads to the formation of a bimodal structure which has large grains of several hundred micrometers surrounded by a layer of the fine-grained structure. As the result of the further treatment by extrusion at 710°C the volume fraction of the fine-grained structure is increased. At the same time, anisotropy of thermal expansion during the martensitic transformation is observed in the alloys in both states due to residual tensile stresses introduced in the last stages of treatment. The performed investigation shows high potential of the thermo-mechanical treatment for obtaining structurally modified Heusler alloys having a sufficient level of functional and service properties for practical applications. 10.18720/MPM.4022018_8 Heusler alloys martensitic transformation thermo-mechanical treatment multiple isothermal forging extrusion EBSD texture anisotropy https://mpm.spbstu.ru/article/2018.66.8/ MPM240_08_musabirov.pdf

RAR RUS 212-220 Nosov Magnitogorsk State Technical University Pivovarova

Magnitogorsk, Russia

Nosov Magnitogorsk State Technical University Polyakova

Magnitogorsk, Russia

University of Padova Dabala

Padova, Italy

Nosov Magnitogorsk state technical university Korchunov

Magnitogorsk, Russia

Peter the Great St. Petersburg Polytechnic University Shymchenko

St.Petersburg, Russia

Modern approaches for study of eutectoid steel oxidation and decarburization This paper describes the results of a laboratory study into the high-temperature surface oxidation and decarburization of eutectoid steel performed using thermal gravimetric analysis which makes it possible to understand the steel surface oxidation kinetics in non-isothermal conditions as the steel specimen is continuously heated to a specified temperature. An exponential relationship is obtained between the heating temperature and the iron loss in steel. A relationship is established between the heating temperature applied and the surface oxidation rate observed in a eutectoid steel specimen. It is shown that when the temperature of the specimen is raised from 900 to 1000°С, it leads to a triple increase in the surface oxidation rate, whereas the temperature increase to 1200°С results in an eightfold increase in the surface oxidation rate. It is noted that, within the temperature range of 720-950°С, the phase transformations observed are accompanied with intensified scale formation and surface carbon depletion. Using the emission spectrometry technique, the concentration of carbon is determined in the surface layer in relation to the heating temperature and time. The results obtained indicate that eutectoid steel is subjected to an intense surface decarburization at the temperatures of 600-1200°С. 10.18720/MPM.4022018_9 eutectoid steel thermal gravimetric analysis differential scanning calorimetry oxidation decarburization https://mpm.spbstu.ru/article/2018.66.9/ MPM240_09_pivovarova.pdf

RAR RUS 221-230 Peter the Great St. Petersburg Polytechnic University Kobykhno

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Kuznetсov

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Didenko

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Smirnova

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Vaganov G.V.

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Ivanov

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Popova

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Litvinova

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Svetlichnyi

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Vasilyeva E.S.

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Tolochko

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Yudin

St.Petersburg, Russia

Institute of Macromolecular Compounds of RAS Kudryavtsev

St.Petersburg, Russia

Multiblock copoly(urethane-amide-imide)s with the properties of thermoplastic elastomers Multiblock (segmented) copoly(urethane-amide-imide)s containing flexible segments of polypropylene glycol (PPG) and rigid segments of bis(urethane-amide-imide) in repeating units were obtained and investigated. Copolymers were prepared of PPG terminated by 2,4-toluyilene diisocyanate (Mn=2300), 4-chloroformylphthalic anhydride and aromatic diamines. Thermal properties of copolymers were analyzed by TGA and DSC methods. The mechanical properties of copolymer films were measured by tensile test and DMA method. It is shown that copolymers have elastomer properties. The chemical structures of copolymers capable of processing by injection molding were determined and the mechanical properties of the obtained moldings were estimated. A conclusion was drawn that the studied copolymers have the properties of thermoplastic elastomers (thermoelastoplasts). 10.18720/MPM.4022018_10 polyurethanes polyamide-imides multiblock (segmented) copolymers thermal stability glass transition temperature mechanical properties films injection molding thermoplastic elastomers https://mpm.spbstu.ru/article/2018.66.10/ MPM240_10_kobykhno.pdf

RAR RUS 231-238 Peter the Great St. Petersburg Polytechnic University Smirnov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Lebedev

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Aleshin

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Rozhdestvenskiy

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Nikulina

St.Petersburg, Russia

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

St.Petersburg, Russia

Revisited applicability of polymeric composite materials for designing tractor hoods The paper shows the possibility of using composite materials for design and production of tractor hoods. A method for calculating thermal loads with allowance for convection and radiation in the underhood space and its application in thermoelastic calculation were developed. The results of the most thermoelastic calculation of the hood, taking into account its composite structure and using aeroelasticity approaches, are presented; the paper shows necessity to allow for thermal loads when designing a hood of a composite material. Application of the method described in this paper allowed calculating the hood deformation under constant thermal loads and showed the advantages of using a composite material. 10.18720/MPM.4022018_11 optimization polymeric composite materials (PCM) aerodynamics radiation convection thermoelasticity and aeroelasticity https://mpm.spbstu.ru/article/2018.66.11/ MPM240_11_smirnov.pdf

RAR RUS 239-245 Lobachevsky State University of Nizhni Novgorod Balandin

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Ezhov

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Petrakov

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Fedotov

Nizhny Novgorod, Russia

Multi-criteria problems for optimal protection of elastic constructions from vibration In a multi-objective formulation with criteria such as the maximal deformation of the elastic object to be protected and maximal forces created by protection devices, a new class of optimal vibration protection problems is considered. A general approach to solving these problems based on results of modern control theory using linear matrix inequalities technique is presented. An example of a solution of two-criteria problem for a high-storey building under seismic disturbances is given. 10.18720/MPM.4022018_12 optimal vibration isolation multi-criteria problem linear matrix inequalities Germeyer convolution https://mpm.spbstu.ru/article/2018.66.12/ MPM240_12_balandin.pdf

RAR RUS 246-253 Peter the Great St. Petersburg Polytechnic University Shcherba

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

Developing of phenomenological damage model for automotive low-carbon structural steel for using in validation of euroncap frontal impact Results presented in this paper demonstrate the process of material models development for automotive structural steels in order to implement it into the SUV digital twin. Developed digital twin is capable to simulate vehicle crash impact in the same way as full-scale test but among of many parameters it needs correctly defined material models. One of the most difficult things to develop is failure models which simulate the behavior of real material correctly. Usually standard approach considers using only stress-strain curves for several strain rates that does not follow the requirements of advanced model of digital twin. Implementing of damage theory based GISSMO failure description into the vehicle model, especially for high strain rates, leads to achieving good correlation with full-scale crash tests. Also it helps to improve digital twin's quality and speed up overall process of vehicle developing. As a result of research this paper demonstrated the difference of simulations between usual and improved material models. 10.18720/MPM.4022018_13 damage GISSMO digital twin vehicle crash test triaxiality https://mpm.spbstu.ru/article/2018.66.13/ MPM240_13_shcherba.pdf

RAR RUS 254-260 Don State Technical University Vasiliev

Rostov-on-Don, Russia

Don State Technical University Volkov

Rostov-on-Don, Russia

Don State Technical University Aizikovich

Rostov-on-Don, Russia

Southern Federal University Litvinenko

Rostov-on-Don, Russia

Indentation of an elastic half-space reinforced with a functionally graded interlayer by a conical punch An elastic half-space with a two-layered coating is considered. The upper layer is homogeneous while the lower layer is assumed to be made of a functionally graded material. Elastic moduli of the interlayer vary with depth according to arbitrary differentiable functions. The half-space is indented by a rigid conical punch. Approximated analytical expressions for the contact stresses are obtained using the bilateral asymptotic method. Expressions for the subsurface stresses and displacements are obtained in the form of some quadratures. Numerical results illustrating difference between the stress distributions for one- and two-layered coatings are presented 10.18720/MPM.4022018_14 contact indentation conical punch two-layered coating functionally graded interlayer elasticity analytical methods https://mpm.spbstu.ru/article/2018.66.14/ MPM240_14_vasiliev.pdf

RAR RUS 261-273 Don State Technical University Zelentsov

Rostov-on-Don, Russia

Don State Technical University Mitrin

Rostov-on-Don, Russia

Don State Technical University Aizikovich

Rostov-on-Don, Russia

Don State Technical University Lapina

Rostov-on-Don, Russia

Don State Technical University Sukiyazov

Rostov-on-Don, Russia

Monitoring of sliding contact with wear by means of piezoelectric interlayer parameters The contact problem on frictional sliding of a rigid body over a coating's surface is considered. During sliding, frictional heating and wear of the coating takes place at the contact interface. A piezoelectric interlayer is placed between the coating and the rigid substrate, which edges are perfectly bonded to the substrate and to the lower boundary of the coating. Electrodes are located at the edges of the interlayer, being connected to the control circuit and subjected to electric potential difference. Solutions of the problem were represented in form of the Laplace convolutions. They allow to determine relationship between electric current in the interlayer and main parameters of the contact: temperature, contact stresses, displacements, coating's wear. Also the obtained solutions show that one can alter contact parameters by changing the potential difference on electrodes of the interlayer. 10.18720/MPM.4022018_15 wear sliding contact thermoelasticity piezoelectricity coating piezoelectric interlayer https://mpm.spbstu.ru/article/2018.66.15/ MPM240_15_zelentsov.pdf

RAR RUS 274-284 Samara University Grechnikov

Samara, Russia

Samara University Erisov

Samara, Russia

Samara University Surudin

Samara, Russia

Peter the Great St. Petersburg Polytechnic University Tereshchenko

St.Petersburg, Russia

Theoretical and experimental study of plastic anisotropy of Al-1Mn alloy taking into account the crystallographic orientation of the structure The paper establishes a relationship between the indicators of plastic anisotropy (coefficient of transverse deformation) and the parameters of the structure of the material. It was also investigated the change of crystallography of the structure and anisotropy parameters on the example of rolling of Al-1Mn alloy (grade 1400). In general, the results of studies indicate a fairly good convergence of the calculated and experimental data, therefore the developed models of plastic flow of anisotropic material, taking into account the crystallographic orientation of the structure, adequately describe the anisotropy of the deformation characteristics of sheet materials. Crystallographic orientations contributing to an increase in the coefficients of transverse deformation are established and also leads to the creation of transverse isotropy. The conducted studies confirm the principal possibility of forming a given crystallographic structure in the sheets which provides an increase in the deformation capabilities of the material in the molding process. 10.18720/MPM.4022018_16 plastic anisotropy crystallographic orientation of the structure the plasticity criterion the coefficients of transverse deformation rolling data storage systems https://mpm.spbstu.ru/article/2018.66.16/ MPM240_16_grechnikov.pdf

RAR RUS 285-295 Samara National Research University Mikheev

Samara, Russia

Samara State Technical University Doroshko

Samara, Russia

Samara National Research University Grechnikova

Samara, Russia

Samara National Research University Agafonova

Samara, Russia

Application of temperature analysis to account for the effect of sheet thickness on rolling force The relationship between the rolling force and the initial thickness of the Al-Mg-Li sheet preform for thicknesses of 1.8 mm and 4.8 mm was shown for cold rolling prequenched and artificial aging. Samples with a thickness of 7.3 mm were obtained by hot rolling with cooling from the deformation temperature. Thermoanalytical support of the rolling process is carried out by the method of temperature analysis based on isothermal discrete scanning (IDS) data. It gives the connection of effort with internal temperature distributions, which have general patterns of properties, regardless of the complexity of the structure and composition of the material. The presence of periodicity and steady-state temperatures after IDS makes it possible to partition the results of the temperature scanning of the samples into sections. As a result, it is possible to improve the accuracy of estimating the effect of the initial thickness of the workpiece on the force for each of the passes during cold rolling, without correction for the thermal or technological past. 10.18720/MPM.4022018_17 Al-Mg-Li sheet cold rolling temperature analysis https://mpm.spbstu.ru/article/2018.66.17/ MPM240_17_mikheev.pdf

RAR RUS 296-303 Moscow Aviation Institute (National Research University) Vestyak

Moscow, Russia

Lobachevsky State University of Nizhni Novgorod Igumnov

Nizhni Novgorod, Russia

Lomonosov Moscow State University Tarlakovskiy

Moscow, Russia

Electromagnetic elastic ball under non-stationary axially symmetrical waves This paper studies propagation of non-stationary axially symmetrical kinematic or electromagnetic disturbances applied on the surface of a ball. To this end, linear equations of motion of an elastic ball together with Maxwell equations are used as well as linearized generalized Ohm law and Lorentz force equation. The required functions are expanded in series in terms of Legendre and Gegenbauer polynomials. Laplace integral time transformation and expansion of coefficients of series into power series in small parameter linking mechanical and electromagnetic properties of the medium enabled finding recurrent sequence of boundary value problems with respect to components of mechanical and electromagnetic fields. The solution of each problem is represented in the form of generalized convolution of functions corresponding to previous members of the recurrent sequence with Green functions. 10.18720/MPM.4022018_18 Green functions electromagnetic disturbances linear equations of motion of elastic ball Ohm law https://mpm.spbstu.ru/article/2018.66.18/ MPM240_18_vestyak.pdf

RAR RUS 304-312 University of Shahreza Motamedi

Isfahan, Iran

Comsats University Islamabad Sohail

Pakistan

Biophysical analysis of microtubules nonlocal beam theory Microtubules are filamentous intracellular structures that are responsible for various kinds of movements in all eukaryotic cells. The dynamic assembly and disassembly of microtubules and the mechanical properties of these polymers are essential for many key cellular processes such as spermatogenesis and the processes of neurons. Mathematical and computational modeling, especially coupled mechanochemical modeling, has contributed a lot to understand their dynamics. However, it has remained a great challenge to reduce the critical discrepancies, which exist between the experimental observations and modeling results. During this research, the small scaling parameter of the nonlocal Euler-Bernoulli beam theory is analyzed to demonstrate the free vibration problem of microtubules. 10.18720/MPM.4022018_19 microtubules nonlocal parameter finite element Euler-Bernoulli beam theory https://mpm.spbstu.ru/article/2018.66.19/ MPM240_19_motamedi.pdf