Materials physics and mechanics

RAR RUS 1-4 Moscow State University of Mechanical Engineering (MAMI) Bondar

Moscow, Russia

Theory of plasticity without surface of loading On the basis of hysteresis loop analysis (cyclic diagram) there are distinguished three parts, which characterize different behaviors of stresses, that is distinguished three types of stresses. For each type of stresses there are formulated corresponding evolutionary equations for anisotropic hardening. For description isotropic hardening the evolutionary equation with parameter of saturation for second type stresses is introduced. The deviator of stresses is determined as sum of three types of stresses. For description of the non-linear process of accumulation damages the kinetic equation is introduced, basing on energetic principle, where in quality of energy, which expending on creating of damages in material there is energy equal work of second type stresses on full deformation field. The material functions, which completed the theory and subjected to experimental determining, are distinguished. theory of plasticity; hysteresis loop analysis; anisotropic hardening https://mpm.spbstu.ru/article/2015.40.1/ MPM123_01_bondar.pdf

RAR RUS 5-9 Lobachevsky State University of Nizhni Novgorod Erofeev

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Igumnov

Nizhni Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Pavlov

Nizhni Novgorod, Russia

The mathematical model for anisotropic material with auxetic properties A two-dimensional model representing a square lattice of round particles is proposed for description of auxetic properties of an anisotropic crystalline material with cubic symmetry. It is assumed that each particle has two translational and one rotational degrees of freedom. Differential equations describing the propagation of elastic and rotational waves in such a medium have been derived. Relationships between the macroelasticity constants of the medium and the parameters of its inner structure have been found. It has been shown that the Poisson's ratios of the anisotropic material can be negative for certain values of the parameters of its inner structure. anisotropic material; auxetic properties; two-dimensional model https://mpm.spbstu.ru/article/2015.40.2/ MPM123_02_pavlov.pdf

RAR RUS 10-13 National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) Murashkin E.V.

Moscow, Russia

A. Ishlinsky Institute for Problems in Mechanics RAS Radayev

Moscow, Russia

On a classification of weak discontinuities in micropolar thermoelasticity The present study is devoted to problem of propagating surfaces of weak discontinuities of translational displacements, microrotations and temperature in type-I micropolar (MP) thermoelastic (TE) continuum. Geometrical and kinematical compatibility conditions due to Hadamard and Thomas are used to study possible wave surfaces of weak discontinuities in MPTE-I continua. Weak discontinuities are discriminated according to spatial orientations of the discontinuities polarization vectors (DPVs). It is shown that the surfaces of weak discontinuities can propagate exist without weak discontinuities of the temperature field. type-I micropolar thermoelastic continuum; translational displacements; microrotations; temperature; weak discontinuities https://mpm.spbstu.ru/article/2015.40.3/ MPM123_03_murashkin.pdf

RAR RUS 14-19 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

Beijing Jiaotong University Ke

Beijing, China

Instability of solution of the dynamic sliding frictional contact problem of coupled thermoelasticity We consider one-dimensional thermoelastic contact problem on vertical indentation of a rigid thermally insulated half-plane moving horizontally with constant speed over an elastic coating (strip), while bottom side of the latter is bonded to a rigid foundation. Thermal flux generated by friction is directed to the strip. Temperature, displacement and stress distributions along the depth of the coating are derived in the form of infinite series over eigenfunctions. It is shown that the thermoelastodynamic instability of the obtained solutions is present in all time range and at any velocities of the half-plane sliding over the surface of the coating. one-dimensional thermoelastic contact problem; a rigid half-plane moving horizontally; instability of solution https://mpm.spbstu.ru/article/2015.40.4/ MPM123_04_mitrin.pdf

RAR RUS 20-24 Institute of Mechanics, National Academy of Sciences of the Republic of Armenia Belubekyan

Yerevan, Armenia

Lobachevsky State University of Nizhni Novgorod Erofeev

Nizhny Novgorod, Russia

Institute of Mechanics, National Academy of Sciences of the Republic of Armenia Shekoyan

Yerevan, Armenia

Influence of point defects on ultrasonic waves propagating in the thin plate In the linear formulation a two-dimensional self-consistent problem of the propagation of elastic (ultrasonic) waves in the plate, taking into account its interaction with point defects present in its material is provided. We study the effect of point defects on the dispersion laws of planar and bending elastic waves. ultrasonic waves; thin plate; point defects https://mpm.spbstu.ru/article/2015.40.5/ MPM123_05_erofeev.pdf

RAR RUS 25-30 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

Peculiarities of the wave field localization in the functionally graded layer Within the framework of the linearized theory of elasticity, as exemplified by the problem of the shear harmonic oscillations of the pre-stressed functionally graded layer, the influence of the type of inhomogeneity and of the character of the initial stressed state on the distribution of the displacements with depth is investigated. The initially deformed state is assumed to be homogeneous, the inhomogeneity of the initial stresses is caused by the change of the material properties. The transformation of the displacements with depth for different oscillation frequencies of the layer under the conditions of the equal and arbitrary intensity of the change of properties is demonstrated. The possibility to dampen the amplitude of displacements at the definite frequencies by means of changing the initial actions is established. linearized theory of elasticity; shear harmonic oscillations; pre-stressed functionally graded layer; inhomogeneity https://mpm.spbstu.ru/article/2015.40.6/ MPM123_06_belyankova.pdf

RAR RUS 31-35 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 field in moving space with spherical enclosure The unsteady axisymmetric problem being considered is related to the identification of the components of electromagnetic field in moving space with spherical enclosure filled with homogeneous isotropic conductor. The model used includes Maxwell's equations and generalized Ohm's law. In order to find a solution, a series expansion in Legendre polynomials and Laplace time transform are applied. Integral representations of the components of the electromagnetic field with Green's function kernels have been generated. electromagnetic field; moving space with spherical enclosure; Green's function https://mpm.spbstu.ru/article/2015.40.7/ MPM123_07_vestyak.pdf

RAR RUS 36-41 Moscow Aviation Institute (National Research University) Zemskov

Moscow, Russia

Lomonosov Moscow State University Tarlakovskiy

Moscow, Russia

Method of the equivalent boundary conditions in the unsteady problem for elastic diffusion layer The proposed approach to solving initial-boundary problems is based on integral relations which connect right sides of boundary conditions of different types. One of these solutions is assumed to be found. In this case, integral relations are considered as equations as regard to right sides which are equivalent to other conditions. Quadrature formulas are used to solve these equations. initial-boundary problems; method of the equivalent boundary conditions https://mpm.spbstu.ru/article/2015.40.8/ MPM123_08_zemskov.pdf

RAR RUS 42-46 Southern Scientific Center of Russian Academy of Sciences Levi

Rostov-on-Don, Russia

Lobachevsky State University of Nizhni Novgorod Igumnov

Nizhni Novgorod, Russia

Some properties of the thermoelastic prestressed medium Green function The dynamic coupled problem of excitation of harmonic oscillations on the layered prestressed thermoelastic body surface is considered. The body is under the action of the oscillating heat flow which is distributed on the surface in a certain region. It is a layer which is rigidly coupled to a half-space. The layer surface is assumed to be free from mechanical stress and outside the thermal stress region is thermal insulated. Thermal and mechanical effects induce initial stress state. The influence of different prestressing cases on the Green function poles distribution is investigated. thermoelasticity; dynamics; contact problem; initial strain; preheating; thermoelastic waves; initial stress; Green's function; dispersion curves; layered body https://mpm.spbstu.ru/article/2015.40.9/ MPM123_09_levi.pdf

RAR RUS 47-51 7006355365 0000-0002-6663-6357 Kuban State University Babeshko Vladimir

Krasnodar, Russia

57201387701 Southern Scientific Center RAS Evdokimova Olga

Rostov-on-Don, Russia

6602333282 0000-0003-1283-3870 Kuban State University Babeshko Olga

Krasnodar, Russia

The analytical solutions of the boundary-value problems by the method of factorization The differential factorization method developed by previously [1, 2] is applied to boundary-value problems for the analytical method [3]. There problems are convenient for comparing different methods of their solution and demonstrate great potentialities of the differential factorization method. It is important to note that these problems include cases involving the main types of roots (simple and double zeros) of the determinants of characteristic equations of the corresponding differential equations. boundary-value problems; method of factorization; analytical solutions https://mpm.spbstu.ru/article/2015.40.10/ MPM123_10_babeshko.pdf

RAR RUS 52-55 Southern Scientific Center of Russian Academy of Sciences Shirokov

Rostov-on-Don, Russia

Southern Scientific Center of Russian Academy of Sciences Kalinchuk

Rostov-on-Don, Russia

Univ. Orléans Shakhovoy

Orléans, France

Southern Federal University Yuzyuk

Rostov-on-Don, Russia

Anomalies of the elastic modulus of thin films of barium titanate For the single-crystal thin films of barium titanate based on Landau potential for eighth degree dependence of the elastic moduli from the misfit strain at room temperature constructed. Elastic moduli at the phase boundaries indicate abnormal behavior. In the region of the r-phase, some modules have the extreme values. elastic modulus; thin films; barium titanate https://mpm.spbstu.ru/article/2015.40.11/ MPM123_11_shirokov.pdf

RAR RUS 56-60 Kuban State University Glushkov

Krasnodar, Russia

Kuban State University Glushkova

Krasnodar, Russia

Kuban State University Eremin

Krasnodar, Russia

Guided wave based nondestructive testing and evaluation of effective elastic moduli of layered composite materials The paper presents a nondestructive technique for the evaluation of elastic moduli of layered fiber-reinforced composites. It is based on the minimization of the discrepancy between the theoretically calculated and experimentally measured dispersion curves of guided Lamb waves generated by surface-mounted piezoelectric wafer active sensors. Numerical simulation is performed in the context of 3D linear elastodynamics for anisotropic solids. It relies on the explicit integral and asymptotic representations derived for the force-generated wave fields in terms of Green's matrix of the composite structure considered. The minimization of the least-square error sum between the measured and calculated data is achieved through a real coded micro-genetic algorithm. The reliability of the proposed approach is experimentally validated via static tensile tests as well as by the frequency response evaluation. laminate composite; guided waves; group velocities; effective elastic properties; piezoelectric actuators; laser vibrometry https://mpm.spbstu.ru/article/2015.40.12/ MPM123_12_glushkov.pdf

RAR RUS 61-65 Lobachevsky State University of Nizhni Novgorod Bragov

Nizhny Novgorod, Russia

Saint Petersburg State University Konstantinov

St.Petersburg, Russia

St.-Petersburg State University Petrov

St.Petersburg, Russia

Saint Petersburg State University Evstifeev

St.Petersburg, Russia

Structural-temporal approach for dynamic strength characterization of rock Test results of rock obtained by split Hopkinson bar apparatus and his modifications. A uniform interpretation of fracture rate effects of the tested marble samples is given on the basis of the incubation time approach based on a set of fixed material constants. Time dependences of both compressive and tensile strengths are calculated using the incubation time fracture criterion. rock; dynamic strength characterization; structural-temporal approach https://mpm.spbstu.ru/article/2015.40.13/ MPM123_13_evstifeev.pdf

RAR RUS 66-70 Lobachevsky State University of Nizhni Novgorod Abrosimov

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Novosel’tseva

Nizhny Novgorod, Russia

The identification of material parameters in nonlinear deformation models of metallic-plastic cylindrical shells under pulsed loading A method of identification of material parameters in defining relations of elastic deformation of composite materials is developed based on the minimization of disagreement between experimental data and the results of numerical analysis of the dynamic behavior of double-layered metallic-plastic cylindrical shells under explosive loading. material parameters; nonlinear deformation models; metallic-plastic cylindrical shells; pulsed loading https://mpm.spbstu.ru/article/2015.40.14/ MPM123_14_abrosimov.pdf

RAR RUS 71-75 Southern Federal University Vatulyan

Rostov-on-Don, Russia

Southern Federal University Nesterov

Rostov-on-Don, Russia

About the specifics of identification thermomechanical characteristics of functionally graded hollow cylinder The coefficient inverse problem for functionally graded hollow cylinder is considered. The direct problem for a cylinder solved based on the joint use of the Laplace transform and the method of adjustment. The solution of the inverse problem is reduced to an iterative procedure, at each step, which is necessary for solving Fredholm integral equation of the 1st kind. Concrete examples of the reconstruction of thermomechanical characteristics are given. functionally graded hollow cylinder; thermomechanical characteristics; Fredholm integral equation of the 1st kind https://mpm.spbstu.ru/article/2015.40.15/ MPM123_15_vatulyan.pdf

RAR RUS 76-78 Komsomolsk-on-Amur State Technical University Khromov

Komsomolsk-on-Amur, Russia

Komsomolsk-on-Amur State Technical University Loshmanov

Komsomolsk-on-Amur, Russia

Komsomolsk-on-Amur State Technical University Sirotin

Komsomolsk-on-Amur, Russia

Influence of density change on fracture in the problem of material cutting Possibility of using technological process of materials cutting to determine fracture characteristics connected to density change in a neighborhood of a crack's peak is considered. fracture characteristics; crack's peak; density change https://mpm.spbstu.ru/article/2015.40.16/ MPM123_16_khromov.pdf

RAR RUS 79-82 Lobachevsky State University of Nizhni Novgorod Kapustin

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Gorokhov

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Churilov

Nizhny Novgorod, Russia

Models and prediction algorithms of fracture of structural elements for low- and high-cycle loading based on FEM Mathematical models, methods, algorithms and developed based on them the results of numerical simulation based on FEM, approaches mechanics of the damaged medium, processes of deformation and fracture (from the generation stage of microdefects to the propagation of the main cracks) of structural elements for low- and high-cycle loading. damage accumulation; fracture; low-cycle; high-cycle; fatigue; crack; extrapolation; FEM https://mpm.spbstu.ru/article/2015.40.17/ MPM123_17_kapustin.pdf

RAR RUS 83-86 Lobachevsky State University of Nizhni Novgorod Glazova

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Kochetkov

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Krylov

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Poverennov

Nizhny Novgorod, Russia

Numerically modeling of explosive loading processes of snow Snow is modeled using S.S. Grigoryan's plastic compressible medium with nonlinear equations of state different for loading and unloading also capable of shear deformation. The adequacy of equation of state in the pressure range from tens to some hundreds megapascals is verified using comparison of one-dimensional plane problem's numerical solution of snow pack impact loading and available experimental data. The numerical solution's results of spherical explosion of blasting charge in snow are presented. Time-history dependences of radial and tangential stresses into the points located on the different distances from charge are analyzed. The analysis results are compared with data of experimental investigations. numerically modeling; explosive; snow; deformation; stress; shock adiabat https://mpm.spbstu.ru/article/2015.40.18/ MPM123_18_kochetkov.pdf

RAR RUS 87-90 Nizhny Novgorod State University of Architecture and Civil Engineering Kislitsyn

Nizhny Novgorod, Russia

Nizhny Novgorod State University of Architecture and Civil Engineering Suprun

Nizhny Novgorod, Russia

Nizhny Novgorod State University of Architecture and Civil Engineering Khromykh

Nizhny Novgorod, Russia

Nizhny Novgorod State University of Architecture and Civil Engineering Domrachev

Nizhny Novgorod, Russia

Computing weakly parallelized calculations of objects made of materials with complex physical-mechanical properties The article demonstrates, by the example of solving a problem of a high degree of static indefinability that the efficiency of parallelizing calculations drops drastically as the number of cores increases. This limits considerably a possibility to design computer systems capable to simulate reliably enough normal and abnormal operation of real technical objects by means of widely used multiprocess hardware. To solve a wide range of problems of deformed solids mechanics, a variant is offered to modernize the method of dividing an object into design units, suggested by the authors earlier, and to divide it into continuums, that provides practically unlimited possibilities for parallelizing a calculation process. computing weakly parallelized calculations; deformed solids mechanics https://mpm.spbstu.ru/article/2015.40.19/ MPM123_19_suprun.pdf

RAR RUS 91-94 Peter the Great St. Petersburg Polytechnic University Kotov

St.Petersburg, Russia

Lobachevsky State University of Nizhni Novgorod Linnik

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Tarasova

Nizhny Novgorod, Russia

The influence of stress distribution on stability of the displacement of conical indenter into the soil medium Plane-parallel displacement of conical bodies in an elastoplastic medium on the basis of the hypothesis of locality is simulated. The parameters of the quadratic velocity model of local interaction are determined by solving the one-dimensional problem of the expansion of a spherical cavity. It is shown that the radial and angular velocity dependent on the stress distribution along the cone at oblique impact. We analyze the behavior of the angular velocity of rotation in time at different positions the center of gravity of a sharp cone. elastoplastic medium; conical indenter; displacement; stress distribution https://mpm.spbstu.ru/article/2015.40.20/ MPM123_20_kotov.pdf