Evgenii Murashkin

• PhD
• Senior Researcher at Ishlinsky Institute for Problems in Mechanics of the Russian Academy of Sciences

The paper deals with a method of the Nye figures construction for micropolar elastic solids. The method of tensors of the 4th and 3rd ranks representations by means of blocks of two-dimensional matrices and relationships between their elements is widely known in crystallography. Such approach makes it possible to simply determine the number of inde...

This article considers a variant of the heat conduction theory of thermal conductivity, in which the heat flux pseudovector has a weight of 1. The pseudoinvariants associated to the heat flux pseudovector are sensitive to mirror reflections and inversions of threedimensional space. The primary purpose of the study was to find a heat flux vector tha...

The paper is devoted to problems related to two-dimensional Nye figures for micropolar continua. The representation technique known from studies on crystallography for 4th, 3rd and 2nd rank tensors is employed by two-dimensional matrices, supplied by relationships between their elements. Such representations are commonly used to simplify a script o...

The present paper deals with the problem of deriving the constitutive equations for the micropolar thermoelastic continuum GN-I in terms of the standard pseudotensor formalism. In most cases, the pseudotensor approach is justified in modeling hemitropic micropolar solids, the thermomechanical properties of which are sensitive to mirror reflections...

Рассматриваются представляющие интерес с точки зрения механики микрополярных континуумов тензоры с постоянными компонентами, полуизотропные тензоры и псевдотензоры. Обсуждаются свойства и способы координатного представления тензоров и псевдотензоров с постоянными компонентами. На основе неконвенционального определения полуизотропного тензора четвер...

The present study deals with the boundary value problems under toroidal symmetry conditions. The residual stresses after cooling (unloading) in an elasto-plastic material are calculated. Throughout the paper the conventional Prandtl-Reuss model is generalised and used. The solution to the problem of hollow torus cooling under a temperature gradient...

The present study is devoted to the boundary value problems statements for the growing materials with microstructural features. The general form of tensor relations on the propagating growing surface is derived as a consequence of the conservation laws of momentum and angular momentum. The necessary system of independent arguments of constitutive d...

Обсуждаются вопросы ковариантного постоянства тензоров и псевдотензоров произвольной валентности и веса в евклидовом пространстве. Приводятся минимально необходимые сведения из алгебры и анализа псевдотензоров. Выясняются условия ковариантного постоянства псевдотензоров. Рассматриваются примеры ковариантно постоянных тензоров и псевдотензоров из мн...

The paper deals with the concept of the force stress pseudotensor and the derivation of equilibrium equations in terms of the Schouten's stress pseudotensor being an affinor density. The definition of Schouten's force stress pseudotensor is mainly based on the notion of a pseudoinvariant element of area. The requisute equations and notions from alg...

Обсуждаются определяющие псевдоскаляры, связанные с теорией гемитропного микрополярного континуума. Приводятся основные понятия алгебры псевдотензоров. Определяется псевдотензорная форма гемитропного микрополярного упругого потенциала, основанная на 9 определяющих псевдоскалярах (из них 3 псевдоскаляра и 6 абсолютных скаляров). Вычисляются веса опр...

Рассматриваются проблемы согласования ориентаций реперов для микрополярного континуума, погруженного во внешнее плоское пространство. Опираясь на понятие элементарного тензорного объема (площади) \(M\)-ячейки, описывается алгоритм сравнения и согласования внешних пространственных ориентаций \(M\)-ячеек. Рассматривается процесс непрерывного переноса...

Professor Akinlabi’s research and her team has focused on the field of advanced and modern manufacturing processes like Laser Additive Manufacturing (AM), in particular laser material processing. Her other research work is focused on laser metal deposition and functionally graded materials of titanium-based alloys and other materials. Some of the s...

The present study deals with a problem of modeling a surface growth process. Governing principles for mechanics of growing solids have been formulated. Within the framework of the surface growth theory, different variants of boundary value problems are discussed. A human blood vessel under pathological growth processes has been considered as an exa...

Рассматривается псевдотензорная формулировка теории микрополярной упругости Нейбера. Приведены и обсуждаются динамические уравнения микрополярного континуума в терминах относительных тензоров (псевдотензоров). Даны определяющие уравнения для линейного изотропного микрополярного твердого тела. Окончательные формы динамических уравнений для изотропно...

The axisymmetric wave propagation is investigated in coaxially layered isotropic functionally graded cylinders with different mass and stiffness properties of the layers. Exact solutions of the governing equations of the wave propagation in the cylinders exist only for isotropic, transversely iso-tropic and piezoelectric transversely isotropic cyli...

Обсуждается принцип вывода граничных условий в краевых задачах механики растущих микрополярных тел. Приводится вывод уравнений динамики микрополярного континуума в терминах относительных тензоров для тел постоянного состава. Указана определяющая квадратичная форма упругого потенцила (абсолютного скаляра) для линейного гемитропного микрополярного те...

Direct laser metal deposition (DLMD) is an additive manufacturing technique that is favourable in industries such as aerospace, biomedical, sports and automotive. Its advanced three-dimensional printing via layer-by-layer additive of a material allows for high-dimensional accuracy of the manufacturing of a part, but the surface finishing is still a...

Composite materials are used for the manufacturing of light weight components and structures in many industries. Composite materials are obtained by combining materials with preferred properties and by synthesizing a new material using two or more materials having the desired properties. The composite material obtained has an enhanced proportion of...

The aim of this investigation is to characterize the effect of process parameters applied to the laser metal deposition of Al-Cu-Ti coatings on titanium substrate (Ti-6Al-4V). After the deposition process was completed, a new hybrid coated surface emerged with improvements in the following areas: improved thermal, mechanical, and metallurgical prop...

The aim of this research is to study the effect of aluminum-based coatings on the new emerging surface properties, producing improved thermal, mechanical, tribological and metallurgical properties, which can withstand adverse environmental conditions using laser metal deposition technique. In this study, laser metal depo-sition was used to produce...

Direct laser metal deposition (DLMD) is an additive manufacturing technique that is favourable in industries such as aerospace, biomedical, sports and automotive. Its advanced three-dimensional printing via layer-by-layer additive of a material allows for high-dimensional accuracy of the manufacturing of a part, but the surface finishing is still a...

Titanium alloy grade 5 is a grade of the titanium material that is in‐demand in the marine, aerospace, biomedical and turbo machinery industries. It offers great properties such as being light weight, good corrosion performance and great strength. However, some of the other properties, namely: its low hardness and poor tribological performance, has...

The study on the optomechanical effect (photostriction) in the material used in 3D printing by layer-by-layer photopolymerization is performed. The calculation - experimental model in the form of a steel console plate with the one-sided photopolymeric coating is developed for studying of this effect. The experimental setup including UV source, the...

The paper deals with the problem of calculation of residual stresses and displacements in functionally graded material under thermal treatment. The investigated multilayered object has a spherical form. The model of thermoelastic plastic deformation is used. The method of construction of analytical solution is proposed and discussed. The distributi...

The paper considers the problem of torsion of a growing viscoelastic prismatic rod with integral boundary conditions at the ends. The process of continuous growth under the influence of torque is studied. The distributions of the intensity of tangential stresses at various stages of the building process are investigated. The calculations of the tor...

The possibility of applications of relative tensors concepts to the mechanics of micropolar continuum and, in particular, for the hemitropic micropolar continua is considered. The fundamental tensors and orienting relative scalars in three-dimensional space are introduced. Permutation symbols and absolute Levi-Civita tensors are investigated in fur...

The article deals with the problem on setting boundary conditions for asymmetric problems in the mechanics of growing solids. Firstly, we study the conditions on the growing surface that are most important from the point of view of the theory completeness. When deriving relations on the growing surface, we use the results known from the algebra of...

Mechanics of additive manufacturing technologies is aimed at improving the quality of the final geometry and mechanical properties of the structures, devices, and parts of fabricated in such a way. Modern research demonstrates significant differences in the mechanical characteristics of solids formed in the result of growth processes as compared wi...

The present study is devoted to the computational problem of the residual stresses inside human blood vessel wall during atherosclerosis. The blood vessel (artery) wall is simulated by the thick-walled very long circular cylinder. The governing and constitutive equations of mechanics of surface growth solids are reminded for thick-walled solid case...

The present study deals with the elastic plastic boundary value problems statements in toroidal coordinates. The basic model relations of the temperature stresses theory are furnished in a toroidal coordinate system. The computation problem of the stress-strain state of a hollow elastic-plastic torus subjected to uneven radial heating is considered...

Предлагается один общий принцип постановки граничных условий в краевых задачах механики растущих тел. При выводе определяющих соотношений на поверхности наращивания используется аппарат алгебры рациональных инвариантов. Проведен вывод различных вариантов физически непротиворечивых дифференциальных ограничений на поверхности наращивания. Полученные...

The present study is devoted to analysis of coupled harmonic waves of translational displacements and microrotations propagating along the axis of a long cylindrical waveguide with circular cross-section. Microrotation waves modelling is realized within the frameworks of linear micropolar elasticity by introducing microrotations as independent degr...

Contemporary models of solids of thermoelasticity requires to include multiphysics coupling and employ non classical e.g. elastic behavior. The permanent generalization of elastic model is the Cosseratt micropolar model. Now this model is to be applied to growing solids, biomaterials, granular media, concrete. The basic concepts of the continuum me...

We use the solution of a one-dimensional problem of the theory of thermal stresses in an elastoplastic tube heated on its interior surface and maintained at a constant temperature on the exterior surface as an example to make a comparison of both the results and solution methods depending on the choice of each of three conventional yield criteria:...

The present study is devoted to the problem of formulation of conservation laws in divergent form for hyperbolic thermoelastic continua. The field formalism is applied to study the problem. A natural density of thermoelastic action and the corresponding variational least action principle are formulated. A special form of the first variation of the...

The present paper is devoted to mathematical modelling of complex continua deformations considered as immersed in an external plane space. The complex continuum is defined as a differential manifold supplied with metrics induced by the external space. A systematic derivation of strain tensors by notion of isometric immersion of the complex continuu...

The present study is devoted to the problem of residual stresses calculation in AM fabricated ball during heating. Strains of the ball are assumed to be small, which allows to use the apparatus of the theory of thermoelastoplastic akin to Prandtl and Reuss. The problem of the evolution of the field of residual stresses in the ball at a given temper...

The present paper is devoted to plane harmonic waves of displacements and microrotations propagating in fully coupled thermoelastic continua. The analysis is carried out in the framework of linear conventional thermoelastic micropolar continuum model. The reduced energy balance equation and the special form of the Helmholtz free energy are discusse...

A propagation problem for coupled harmonic waves of translational displacements and microrotations along the axis of a long cylindrical waveguide is discussed at present study. Microrotations modeling is carried out within the linear micropolar elasticity frameworks. The mathematical model of the linear (or even nonlinear) micropolar elasticity is...

The present study is devoted to the set of boundary value problems in the frameworks of coupled thermoelastoplasticity under axial symmetry conditions for a composite circular cylinder. Throughout the paper the conventional Prandtl–Reuss elastic–plastic model generalised on the thermal effects is used. The yield stress is assumed by linear function...

The present paper deals with the problem of the elastic-plastic plate heating. Considering problems are solved with the various yield stress depending on temperature. Throughout the paper the model of thermo-elastic-plastic deformation are used. We consider Tresca yield criterion, von Mises one, and Ishlinskiy-Ivlev one. The boundaries of the irrev...

The present study is devoted to the boundary value problem of coupled thermoelastoplasticity. The temperature depended yield criterion and Duhamel Neumann constitutive equation was used. The material subjected to uneven heat treatment under plane strain frameworks was considered. The new analytical solution of the problem of uneven heat treatment o...

Propagation problem for coupled harmonic waves of translational displacements and microrotations along the axis of a long cylindrical waveguide is discussed at present study. Microrotations modeling is carried out within the linear micropolar elasticity frameworks. The coupled system of vector differential equations of micropolar elasticity is pres...

The present study is devoted to the problem of the thermal stresses theory for a hollow thermoelastic-plastic ball under unsteady heating. Throughout the paper the conventional elastic-plastic Prandt-Reuss model generalized on the thermal effects is used with the Tresca yield criterion linearly depending on temperature. A numerical-analytical algor...

The problem of centrally symmetric deformation of a multilayer elastoplastic ball in the process of successive accretion of preheated layers to its outer surface is considered in the framework of small elastoplastic deformations. The problems of residual stress formation in the elastoplastic ball with an inclusion and a cavity are solved under vari...

The present study is devoted to the boundary value problems of the perfect thermoelastic-plastic continua concerning to the hollow cylinder deforming under non-stationary thermal action. The conventional Prandtl-Reuss elastic-plastic model generalized on the thermal effects is used. The irreversible deformations, residual stresses, and displacement...

The present paper is devoted to formulations of constitutive equations for the non-linear Green-Naghdi type-III thermoelastic continuum consistent with the principle of thermodynamic (or thermomechanical) orthogonality. Contrary to the original Green-Naghdi model the Lagrange description is employed. The principle of thermodynamic orthogonality ori...

The present study deals with the multiphysics modelling frameworks for the elasticcreep-plastic material. The proposed theory of large deformations is based on the classical formalism of nonequilibrium thermodynamics. Reversible and irreversible components of total deformations are derived by the constitutive differential equations. The development...

A non-linear mathematical model of thermoelastic micropolar continuum is developed. The model is presented in terms of 4-covariant field theoretical formalism. Lagrangian density for thermoelastic continuum with three micropolar directors is given and the least action principle is formulated. Corresponding field equations of micropolar thermoelasti...

The present study is devoted to the statement of compatibility conditions on propagating wave sur- faces of strong and weak discontinuities in thermoelastic continua with microstructure. The field formalism is used to study the problem. A natural density of thermoelastic action and the corresponding variational least action principle are stated for...

This book shows impressively how complex mathematical modeling of materials can be applied to technological problems. Top-class researchers present the theoretical approaches in modern mechanics and apply them to real-world problems in solid mechanics, creep, plasticity, fracture, impact, and friction. They show how they can be applied to technolog...

The present study is devoted to the boundary value problem of thermoelastoplasticity. The new analytical solution of the problem of irregularly heating of the thermo-elastic-plastic hollow cylinder was constructed. The Ishlinsky-Ivlev's and Tresca's yield conditions were used as the plastic potential. The yield stress was assumed linear depending o...

A mathematical model of the large deformations of materials with elastic, plastic and viscous properties is proposed. Non-linear viscous properties develop during deformation preceding plastic flow and, on unloading, in the form of creep of the material and, during its flow, in the form of viscous resistance to plastic flow. The rheological mechani...

The present study is devoted to the problem of optimal loading pressure identification by the prescribed displacements vector. The framework of finite elastocreep strains is used. The problem of deformation of the material in the vicinity of microdefect was considered. Integro-differential equations for the external pressure, irreversible deformati...

The dimensional problem of a formation of the residual stresses in the thin circular elastoplastic plate under the given thermal action was analytically solved. The generalized Prandtl-Reuss thermoelastoplastic model was used. The effect of the non-stationary temperature gradient on the residual stresses field formation was investigated under the c...

The present study is devoted to the problem of optimal loading pressure computing by the prescribed displacements vector. The mathematical model of finite elastocreep deformations is used. The boundary value problem of residual stresses forming in microdefect material was considered. Integro-differential equations for the external pressure, irrever...

Evgeniy Dats, Sergey Mokrin, and Evgenii Murashkin Calculation of the Residual Stresses of Hollow Cylinder under Unsteady Thermal Action // Lecture Notes in Engineering and Computer Science: Proceedings of The World Congress on Engineering 2015, 1-3 July, 2015, London, U.K., pp.1043-1046. http://www.iaeng.org/publication/WCE2015/ ISBN 978-988-14047...

The present study is devoted to problem of propagating surfaces of weak and strong discontinuities of translational displacements, microrotations and temperature in micropolar (MP) thermoelastic (TE) continua. Problems of propagation of weak discontinuities in type-I MPTE continua are discussed. Geometrical and kinematical compatibility conditions...

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 discontinuitie...

The object of research is the process of forming metal preform with predetermined configuration under creep at high temperatures. Two deformation modes have been considered – “cold” and “hot”. The results of numerical modeling of two deformation modes using the system MSC Marc are presented.

The one-dimensional process of material deformation due to local heating and subsequent cooling is analyzed in the framework of the classical theory of elastoplastic deformations. The problem of formation of residual stresses in a thin plate made of an elastoplastic material under a given thermal action is solved. The graphs of fields of residual s...

A solution is given for a sequence of boundary value problems in the theory of large deformations of materials with elastic, plastic, and viscous properties. This sequence is related to viscoelastic deformation and determination of the time and location of the plastic flow origination, development of this flow, and the subsequent unloading of the m...

We propose a mathematical model of large elastocreep deformations. As part of the constructed mathematical model the problem of deformation of the material in the vicinity of microdefect was solved. Integro-differential dependence of external pressure from irreversible deformations and displacements was obtained. The laws of loading material from v...

The formation of residual stresses in the vicinity of a single defect of continuity in the process of intense impulse loading surface with considerable distance from the defect is examined. Modeling is carried out within the framework of large elastic-plastic deformation. In the vicinity of the defect there is level of stress, leading to its elimin...

We propose a mathematical model of large elastoplastic deformations with rheological features. As an example of applying the model relations, we present a solution of the boundaryvalue problem on collapsing process of microdefect continuity in elastic-creep-plastic materials under uniform pressure. In the case of a single micropore we obtained quan...