Труды сотрудников ИВМ СО РАН

/ O. V. Sadovskaya // Proceedings of XLI International Summer School–Conference APM 2013. - 2013. - P484-491
Аннотация: Mathematical model for the description of deformation of a porous metal is constructed on the basis of generalized rheological method. In this method a new rheological element, so-called rigid contact, is used to describe the uniaxial deformation of materials with different resistance to tension and compression. Change in the resistance of a porous metal to external loads, when the collapse of pores occurs, is taken into account by means of the von Mises–Schleicher strength condition. Irreversible deformation is described with the help of yield condition, modeling the plastic loss of stability of porous skeleton. For a homogeneous porous medium the fields of displacements and stresses in the problem of radial expansion of spherical and cylindrical cavities under the action of internal pressure considering the effect of collapse of pores are constructed in closed form. The algorithm of numerical realization of the model of dynamic deformation of metal foams on multiprocessor computer systems of the cluster type is worked out

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ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Садовская, Оксана Викторовна

[Text] / V. M. Sadovskii, O. V. Sadovskaya, A. A. Luk'yanov // J. Appl. Mech. Tech. Phys. - 2014. - Vol. 55, Is. 4. - P689-700, DOI 10.1134/S0021894414040154. - Cited References: 18. - This work was supported by the Russian Foundation for Basic Research (Grant No. 14-01-00130). . - ISSN 0021-8944. - ISSN 1573-8620РУБ Mechanics + Physics, Applied

Аннотация: A solution describing the displacement and stress fields around expanding spherical and cylindrical cavities with allowance for pore collapse is constructed using the theory of small elastic deformations of a homogeneous isotropic porous medium in closed form. Transition of the medium into a plastic state is modeled using the Tresca-Saint Venant yield condition. Porosity change is described on the basis of a mathematical model developed taking into account the increase in the stiffness of the porous material at the moment of pore collapse. It is shown that in the elastic deformation stage, the porosity does not change; an increase in the pressure leads to the formation of a region of plastic compression, in part of which, the pores collapse. Stress and displacement fields in the porous medium during unloading are constructed. It is shown that under certain conditions, the elastic unloading stage is followed by the plastic reflow stage to form a region of pore expansion. As the pressure decreases, the boundary of this region simultaneously reaches the region of plastic reflow and the region of pore collapse.

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Держатели документа:
ИВМ СО РАН

Доп.точки доступа:
Sadovskii, V.M.; Садовский, Владимир Михайлович; Sadovskaya, O.V.; Садовская, Оксана Викторовна; Luk'yanov, A.A.; Russian Foundation for Basic Research [14-01-00130]

[Text] / V. M. Sadovskii, O. V. Sadovskaya // ECCOMAS Thematic Conference - COMPDYN 2013: 4th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering, Proceedings - An IACM Special Interest Conference. - 2013. - P4277-4286
Аннотация: Mathematical model for the description of deformation of a porous material with a random distribution of pores is constructed on the basis of generalized rheological method taking into account the different resistance of a material to tension and compression. Phenomenological parameters of the model are determined by means of the approximate computations for the problem of static loading of a cubic periodicity cell with spherical cavities. Within the framework of this theory the fields of displacements and stresses around expanding cavity of spherical shape in a homogenious space are constructed. It is shown that the porosity does not change at the stage of elastic deformation. When the pressure increases, a zone of plastic compaction is formed in the vicinity of a cavity, and in a part of this zone the collapse of pores takes place. Engineering formulas for calculation of critical pressures of the elastic limit state and the limit state of a medium with open pores, and also the formulas for determining the radiuses of interfaces of zones of plasticity and compaction are obtained. A complex of parallel programs for numerical analysis of the dynamic deformation of porous materials on multiprocessor computer systems is worked out. By means of this complex a series of computations for deformation of the protection elements, made of metal foams, under the action of localizedim pulsive loads was performed. The random nature of distribution of the pores size is taken into account with the help of computer modeling. Computations allow one to estimate plastic dissipative part of the energy of impact.

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Доп.точки доступа:
Sadovskaya, O.V.; Садовская, Оксана Викторовна; Садовский, Владимир Михайлович

[Text] / A. Lukyanov [et al.] // 14th European Conference on the Mathematics of Oil Recovery 2014, ECMOR 2014. - 2014. - Ст. P27
Аннотация: Thermomechanical processes observing in deformable solids under intensive dynamic or quasi-static loadings consist of coupled mechanical, thermal and fracturing stages. The fracturing processes involve formation, motion and interaction of defects in crystals, phase transitions, breaking of bonds between atoms, accumulation of micro-structural damages (pores, cracks), etc. Irreversible deformations, zones of adiabatic shear micro-fractures are caused by these processes. A dynamic fracturing is a complicated multistage process, which includes appearance, evolution and confluence of micro-defects and formation of embryonic micro-cracks, pores that can grow and lead to the breaking-up of bodies with formation of free surfaces. This results in a need to use more advanced mathematical and numerical techniques. This talk presents modeling of irreversible deformation near the tip of a crack in a porous domain containing oil and gas during the hydraulic fracturing process. The governing equations for a porous domain containing oil and gas are based on constructing mathematical model of thermo-visco-elastoplastic media with micro-defects (micro-pores) filled with another phase (e.g., oil or/and gas). The micropores can change their size during the process of dynamical irreversible deformation. The existing pores can expand or collapse. The model was created by using the fundamental thermodynamic principles and, therefore, it is a thermodynamically consistent model. All the processes (i.e., irreversible deformation, fracturing, micro-damaging, heat transfer) within a porous domain are strongly coupled. Therefore, explicit normalized-corrected meshless method is used to solve the resulting governing PDEs. The flexibility of the proposed technique allows running efficiently using a great number of micro- and macrofractures. The results are presented, discussed and future studies are outlined.

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Доп.точки доступа:
Lukyanov, A.; Chugunov, N.; Sadovskii, V.M.; Садовский, Владимир Михайлович; Sadovskaya, O.V.; Садовская, Оксана Викторовна

[Text] / V. M. Sadovskii, O. V. Sadovskaya // AIP Conference Proceedings. - 2015. - Vol. 1648: International Conference on Numerical Analysis and Applied Mathematics (SEP 22-28, 2014, Rhodes, GREECE). - Ст. UNSP 630005, DOI 10.1063/1.4912863. - Cited References:6 . - ISSN 0094-243XРУБ Mathematics, Applied + Physics, Applied

Аннотация: Mathematical model for the description of deformation of a porous metal is constructed on the basis of generalized rheological method, taking into account change in the resistance to external loads, when the collapse of pores occurs. Irreversible deformation is described with the help of yield condition, modeling the plastic loss of stability of a porous skeleton. For a homogeneous porous medium the fields of displacements and stresses in the problem of radial expansion of spherical and cylindrical cavities under the action of internal pressure considering the effect of collapse of pores are constructed in closed form. The algorithm of numerical realization of the model of dynamic deformation of metal foams on multiprocessor computer systems of the cluster type is worked out.

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Держатели документа:
SB RAS, Inst Computat Modeling, Krasnoyarsk 660036, Russia

Доп.точки доступа:
Sadovskii, V.M.; Садовский, Владимир Михайлович; Sadovskaya, O.V.; Садовская, Оксана Викторовна

[Text] / M. M. Simunin [et al.] // Tech. Phys. Lett. - 2015. - Vol. 41, Is. 11. - P1047-1050, DOI 10.1134/S1063785015110103. - Cited References:20. - This work was supported financially by the Russian Science Foundation, project no. 15-19-10017. . - ISSN 1063-7850. - ISSN 1090-6533РУБ Physics, Applied

Аннотация: A structure based on porous anodic alumina with through pores is synthesized. This structure may be of some interest in terms of fabricating electrically switchable membranes. Conducting tubulenes connected to a common input electrode are located in the pores of the structure. It is hypothesized that enhancement of the electric field nonuniformity associated with the indicated structure morphology should help raise the degree of ionic selectivity of the membrane and broaden the range of permissible concentrations of ions in the processed solution. An suggestion regarding the structure of synthesized tubulenes in the context of the problem of suppressing the physical sorption of ions on the pore surface and raising the hydrogen and oxygen reduction potentials relative to those of state-of-the-art field-switchable membranes is also made.

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Держатели документа:
Natl Res Univ Elect Technol MIET, Moscow 124498, Russia.
Siberian Fed Univ, Krasnoyarsk 660041, Russia.
Russian Acad Sci, Siberian Branch, Krasnoyarsk Sci Ctr, Krasnoyarsk 660036, Russia.
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia.
Russian Acad Sci, Inst Computat Modeling, Siberian Branch, Krasnoyarsk 660036, Russia.

Доп.точки доступа:
Simunin, M. M.; Khartov, S. V.; Shiverskii, A. V.; Zyryanov, V. Ya.; Fadeev, Y. V.; Фадеев Ю.В.; Voronin, A. S.; Russian Science Foundation [15-19-10017]

[Text] / O. V. Sadovskaya, V. M. Sadovskii ; ed. M. D. Todorov // APPLICATION OF MATHEMATICS IN TECHNICAL AND NATURAL SCIENCES : AMER INST PHYSICS, 2015. - Vol. 1684: 7th International Conference on Application of Mathematics in Technical (JUN 28-JUL 03, 2015, Albena, BULGARIA). - Ст. UNSP 070005. - (AIP Conference Proceedings), DOI 10.1063/1.4934306. - Cited References:8 . - РУБ Mathematics, Applied + Physics, Applied

Аннотация: The parallel computational algorithm for analysis of the processes of elastic-plastic deformation of a porous medium under the action of external dynamic loads is developed. This algorithm is based on the mathematical model taking into account threshold nature of change in the strength of a material under the collapse of pores. The algorithm is implemented in Fortran by means of functions of the MPI library. The parallel program system has been tested on clusters in computations of the propagation of plane longitudinal shock waves of the compression and in computations of the expansion of a cylindrical cavity in an infinite porous medium. The comparison of numerical results and exact solutions has shown their good qualitative and quantitative correspondence. Using the obtained algorithm, the process of propagation of elastic-plastic waves of the compression in a homogenous porous medium, accompanied by the deformation of a skeleton and the collapse of pores, is analyzed.

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SB RAS, Inst Computat Modeling, Akademgorodok 50-44, Krasnoyarsk 660036, Russia.

Доп.точки доступа:
Sadovskaya, O. V.; Sadovskii, V. M.; Todorov, M.D. \ed.\

[Text] / V. M. Sadovskii, O. V. Sadovskaya ; ed. M. D. Todorov // APPLICATION OF MATHEMATICS IN TECHNICAL AND NATURAL SCIENCES : AMER INST PHYSICS, 2015. - Vol. 1684: 7th International Conference on Application of Mathematics in Technical (JUN 28-JUL 03, 2015, Albena, BULGARIA). - Ст. UNSP 070006. - (AIP Conference Proceedings), DOI 10.1063/1.4934307. - Cited References:18 . - РУБ Mathematics, Applied + Physics, Applied

Аннотация: Based on the generalized rheological method, the mathematical model describing small deformations of a single-phase porous medium without regard to the effects of a fluid or gas in pores is constructed. The change in resistance of a material to the external mechanical impacts at the moment of pore collapse is taken into account by means of the von Mises-Schleicher strength condition. In order to consider irreversible deformations, alongside with the classical yield conditions by von Mises and Tresca-Saint-Venant, the special condition modeling the plastic loss of stability of a porous skeleton is used. The random nature of the pore size distribution is taken into account. It is shown that the proposed mathematical model satisfies the principles of thermodynamics of irreversible processes. Phenomenological parameters of the model are determined on the basis of the approximate calculation of the problem on quasi-static loading of a cubic periodicity cell with spherical voids. In the framework of the obtained model, the process of propagation of plane longitudinal waves of the compression in a homogenous porous medium, accompanied by the plastic deformation of a skeleton and the collapse of pores, is analyzed.

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SB RAS, Inst Computat Modeling, Akademgorodok 50-44, Krasnoyarsk 660036, Russia.

Доп.точки доступа:
Sadovskii, V. M.; Sadovskaya, O. V.; Todorov, M.D. \ed.\

/ I. I. Ryzhkov, A. V. Minakov // J. Membr. Sci. - 2016. - Vol. 520. - P515-628, DOI 10.1016/j.memsci.2016.08.004 . - ISSN 0376-7388
Аннотация: The pressure–driven electrolyte transport through nanofiltration membrane pores with constant surface potential or charge density is investigated theoretically. Two approaches are employed in the study. The first one is based on one–dimensional Nernst–Planck equation coupled with electroneutrality, zero current, and Donnan equilibrium conditions. This model is extended to account for interfacial effects by using a smooth approximation of step function for the volume charge density. The second approach is based on two–dimensional Nernst–Planck, Poisson, and Navier–Stokes equations, which are solved in a high aspect ratio nanopore connecting two reservoirs with much larger diameter. The modification of equations on the basis of Slotboom transformation is employed to speed up the convergence rate. The distributions of potential, pressure, ion concentrations and fluxes due to convection, diffusion, and migration in the nanopore and reservoirs are discussed and analyzed. It is found that for constant surface charge density, the convective flux of counter–ions in the nanopore is almost completely balanced by the opposite migration flux, while for constant surface potential, the convective flux is balanced by the opposite diffusion and migration fluxes. The co–ions in the nanopore are mainly transported by diffusion. A particular attention is focused on describing the interfacial effects at the nanopore entrance/exit. Detailed comparison between one– and two–dimensional models is performed in terms of rejection, pressure drop, and membrane potential dependence on the surface potential/charge density, volume flux, ion concentration, and pore radius. A good agreement between these models is found when the Debye length is smaller than the pore radius and the surface potential or charge density are sufficiently low. © 2016 Elsevier B.V.

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Держатели документа:
Institute of Computational Modelling SB RAS, Akademgorodok, Krasnoyarsk, Russian Federation
Siberian Federal University, Svobodny 79, Krasnoyarsk, Russian Federation

Доп.точки доступа:
Minakov, A. V.; Рыжков, Илья Игоревич

/ V. M. Sadovskii, O. V. Sadovskaya // J. Appl. Mech. Tech. Phys. - 2016. - Vol. 57, Is. 5. - P808-818, DOI 10.1134/S0021894416050072 . - ISSN 0021-8944
Аннотация: The generalized rheological method is used to construct a mathematical model of small deformations of a porous media with open pores. Changes in the resistance of the material to external mechanical impact at the moment of collapse of the pores is described using the von Mises–Schleicher strength condition. The irreversible deformation is accounted for with the help of the classic versions of the von Mises–Tresca–Saint-Venant yield condition and the condition that simulates the plastic loss of stability of the porous skeleton. Within the framework of the constructed model, this paper describes the analysis of the propagation of plane longitudinal compression waves in a homogeneous medium accompanied with plastic strain of the skeleton and densification of the material. A parallel computational algorithm is developed for the study of the elastoplastic deformation of the porous medium under external dynamics loads. The algorithm and the program are tested by calculating the propagation of plane longitudinal compression shock waves and the extension of the cylindrical cavity in an infinite porous medium. The calculation results are compared with exact solutions, and it is shown that they are in good agreement. © 2016, Pleiades Publishing, Ltd.

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Держатели документа:
Institute of Computational Modelling, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, Russian Federation

Доп.точки доступа:
Sadovskii, V. M.; Sadovskaya, O. V.

[Текст] : статья / Г. Г. Крушенко // Вестник Сибирского государственного аэрокосмического университета им. академика М.Ф. Решетнева. - 2016. - Т. 17, № 2. - С. 484-489 . - ISSN 1816-9724
   Перевод заглавия: INCREASE OF THE PURITY OF METAL PRODUCTS SURFACES WITH APPLICATION OF NANOTECHNOLOGIES

УДК	629.12.03 (075.8)

Аннотация: Известно, что качество поверхности металлоизделий механизмов и машин, оцениваемое по величине шероховатости, существенно влияет на их эксплуатационные характеристики. Это касается и рабочих колес (РК) турбонасосных агрегатов (ТНА) жидкостных ракетных двигателей (ЖРД), отливаемых из жаропрочных сплавов, так как этот показатель существенно влияет на объемную подачу компонентов топлива. Однако в связи с трудностями проведения натурного эксперимента на ЖРД в работе были использованы данные, полученные на судовом гребном винте (ГВ), отливаемом из стали, между геометрий которого и функциями РК ТНА имеется определенное сходство. Сходство имеется и в технологиях их изготовления. И те, и другие, во-первых, изготавливают литьем: РК ТНА - способом литья по выплавляемым моделям, ГВ - литьем в песчано-глинистые формы; во-вторых, имеется и сходство в материалах литейных форм: в обоих случаях их основой является песок, а вторым компонентом - жидкое связующее. При этом при литье в песчано-глинистые формы детали зачастую поражаются пригаром - прочно сцепленной с телом отливки коркой, образующейся в результате проникновения жидкого металла в поры между зернами песка формы, которую впоследствии удаляют разными способами, как правило, с ухудшением чистоты поверхности. С целью уменьшения пригара рабочие поверхности форм покрывают огнеупорными красками, представляющими собой суспензии из порошкового наполнителя (графит, пылевидный кварц и др.). Однако применение таких красок не предупреждает образование на отливках пригара из-за крупности частиц наполнителей. В работе использованы противопригарные краски, содержащие нанопорошки тугоплавких химических соединений. При использовании таких покрытий практически полностью предотвращается образование пригара на стальных отливках, включая и описанный в работе судовой гребной винт, и, как результат, повышается чистота и улучшается качество поверхности. Полученные результаты можно использовать при изготовлении форм при литье по выплавляемым моделям РК ТНА.
It is known that the quality of the surface of metal products machinery and equipment measured at the value of the roughness significantly affects their performance. This also applies to the impellers turbopump units (TNA) of liquid rocket engines (LRE), the cast of superalloys, because this figure significantly affects the volumetric flow of the fuel components. However, due to the difficulties of conducting full-scale experiment on LRE, in that article the data from the cast steel ship propellers (SP) were used. There is a certain similarity between geometries of SP and functions of TNA. The similarity of the features and technologies of their production, both of which, firstly, produce a casting: impellers TNA - investment casting process, SP - casting in sand-clay molds, secondly, there is the similarity in the materials of the molds - in both cases, their basis is the sand, and the second component is a liquid binder. At the same time when molding in sand-clay parts often affects the penetration, firmly linked with the body of the casting crust, formed as a result of penetration of liquid metal into the pores between the grains of sand form, which is subsequently removed in a variety of ways, usually with the deterioration of surface cleanliness. To reduce metal penetration work surfaces forms are coated with fireproof paint, representing a suspension of the powder filler (graphite, powdered quartz, etc.). However, the use of such paints does not prevent the formation in castings of metal penetration due to the particle size of the fillers. In this paper a nonstick paint containing nanopowders of refractory chemical compounds is used, the use of such coatings is almost completely prevents the formation of burnt-on steel castings, including the one described in the work of the ship propeller, and, as a result, increased clarity and improved surface quality. The obtained results can be used in the manufacture of molds for the casting of the impellers TNA.

РИНЦ

Держатели документа:
Институт вычислительного моделирования СО РАН

Доп.точки доступа:
Крушенко, Генрих Гаврилович; Krushenko G.G.

[Текст] : статья / Владимир Михайлович Садовский, Оксана Викторовна Садовская // Прикладная механика и техническая физика. - 2016. - Т. 57, № 5. - С. 53-65, DOI 10.15372/PMTF20160507 . - ISSN 0869-5032
   Перевод заглавия: Analyzing the Deformation of a Porous Medium with Account for the Collapse of Pores

УДК

539.37

Аннотация: С использованием обобщенного реологического метода строится математическая модель малых деформаций пористой среды с открытыми порами. Изменение сопротивления материала внешним механическим воздействиям в момент схлопывания пор описывается с помощью условия прочности Мизеса - Шлейхера. При учете необратимой деформации наряду с классическими вариантами условия текучести Мизеса и Треска - Сен-Венана используется условие, моделирующее пластическую потерю устойчивости пористого скелета. В рамках построенной модели анализируется процесс распространения плоских продольных волн сжатия в однородной пористой среде, сопровождающийся пластической деформацией скелета и уплотнением материала. Разработан параллельный вычислительный алгоритм для исследования процессов упругопластического деформирования пористой среды под действием внешних динамических нагрузок. При тестировании алгоритма и программы выполнены расчеты распространения плоских продольных ударных волн сжатия и расширения цилиндрической полости в безграничной пористой среде. Проведено сравнение результатов расчетов с точными решениями, показавшее, что они хорошо согласуются.
The generalized rheological method is used to construct a mathematical model of small deformations of a porous media with open pores. Changes in the resistance of the material to external mechanical impact at the moment of collapse of the pores is described using the Mises~--- Schleicher strength condition. The irreversible deformation is accounted for with the help of the classic versions of the von Mises - Tresca - Saint-Venant yield condition and the condition that simulates the plastic loss of stability of the porous skeleton. Within the framework of the constructed model, this paper describes the analysis of the propagation of plane longitudinal compression waves in a homogeneous medium accompanied with plastic strain of the skeleton and densification of the material. A parallel computational algorithm is developed for the study of the elastoplastic deformation of the porous medium under external dynamics loads. The algorithm and the program are tested by calculating the propagation of plane longitudinal shock waves of compression and cylindrical cavity of in an infinite porous medium. The calculation results are compared with exact solutions, and it is shown that they are in good agreement.

РИНЦ

Держатели документа:
Институт вычислительного моделирования СО РАН

Доп.точки доступа:
Садовская, Оксана Викторовна; Sadovskaya O.V.; Sadovskii V.M.

/ I. I. Ryzhkov, A. V. Minakov // J. Sib. Fed. Univ. Math. Phys. - 2017. - Vol. 10, Is. 2. - P186-198, DOI 10.17516/1997-1397-2017-10-2-186-198 . - ISSN 1997-1397
Аннотация: The pressure–driven electrolyte transport through nanofiltration membrane pores with specified wall potential is investigated theoretically. The finite ion size effect is taken into account by introducing an additional term to electrochemical potential. The two–dimensional Navier–Stokes, Poisson, and modified Nernst–Planck equations are solved numerically in a high aspect ratio nanopore connecting two reservoirs with a larger diameter. The calculations are performed for potassium chloride aqueous solution. In the case of point–like ions, the non–physical rise of counter–ion concentration is observed near the pore wall at large applied voltages. When finite ion size is taken in account, the concentration of counter–ions decreases significantly and saturates to the maximum value. It leads to lower osmotic pressure jump and larger magnitude of potential in the pore. The stronger co–ion depletion observed for finite size ions results in the increase of salt rejection, membrane potential, and required pressure drop. © Siberian Federal University. All rights reserved.

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Institute of Computational Modelling RAS SB, Academgorodok, 50/44, Krasnoyarsk, Russian Federation
Institute of Engineering Physics and Radio Electronics, Siberian Federal University, Svobodny, 79, Krasnoyarsk, Russian Federation

Доп.точки доступа:
Ryzhkov, I. I.; Minakov, A. V.

/ V. M. Sadovskii, O. V. Sadovskaya, A. A. Lukyanov // J. Comput. Phys. - 2017. - Vol. 345. - P834-855, DOI 10.1016/j.jcp.2017.06.001 . - ISSN 0021-9991
Аннотация: The wave processes in blocky media are analyzed by applying different mathematical models, wherein the elastic blocks interact with each other via pliant interlayers with the complex mechanical properties. Four versions of constitutive equations are considered. In the first version, an elastic interaction between the blocks is simulated within the framework of linear elasticity theory, and the model of elastic–plastic interlayers is constructed to take into account the appearance of irreversible deformation of interlayers at short time intervals. In the second one, the effects of viscoelastic shear in the interblock interlayers are taken into the consideration using the Poynting–Thomson rheological scheme. In the third option, the model of an elastic porous material is used in the interlayers, where the pores collapse if an abrupt compressive stress is applied. In the fourth case, the model of a fluid-saturated material with open pores is examined based on Biot's equations. The collapse of pores is modeled by the generalized rheological approach, wherein the mechanical properties of a material are simulated using four rheological elements. Three of them are the traditional elastic, viscous and plastic elements, the fourth element is the so-called rigid contact, which is used to describe the behavior of materials with the different resistance to tension and compression. It was shown that the thermodynamically consistent model is provided, which means that the energy balance equation is fulfilled for an entire blocky structure, where the kinetic and potential energy of the system is the sum of the kinetic and potential energies of the blocks and interlayers. Under numerical implementation of the interlayers models, the dissipationless finite difference Ivanov's method was used. The splitting method by spatial variables in the combination with the Godunov gap decay scheme was applied in the blocks. As a result, robust and stable computational algorithms are built and tested. Using MPI technology, the parallel software was designed for the modeling of wave processes in 2D setting. The numerical results are presented, discussed and future studies are outlined. © 2017 Elsevier Inc.

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Institute of Computational Modeling SB RAS, Krasnoyarsk, Russian Federation
Schlumberger–Doll Research, Cambridge, United States

Доп.точки доступа:
Sadovskii, V. M.; Sadovskaya, O. V.; Lukyanov, A. A.

/ V. M. Sadovskii, O. V. Sadovskaya // Russ. J. Numer. Anal. Math. Model. - 2018. - Vol. 33, Is. 2. - P111-121, DOI 10.1515/rnam-2018-0010. - Cited References:21 . - ISSN 0927-6467. - ISSN 1569-3988РУБ Engineering, Multidisciplinary + Mathematics, Applied

Аннотация: Dynamic processes in block-structured media are described within the framework of a mathematical model where elastic blocks interact with each other through pliable interlayers possessing complex mechanical properties. The case of elastic interaction is considered, the effects of plasticity and viscoelastic shear in block interlayers are taken into account. We use the model of porous fluid-saturated material in interlayers in which pores collapse during sudden or prolonged application of compressive stresses. An implicit difference scheme is constructed for numerical implementation of the model based on principles for construction of Ivanov's schemes with controlled energy dissipation. UsingMPI (Message Passing Interface), we developed parallel software for modelling wave motion in a two-dimensional formulation. The results of numerical analysis are presented for the waves initiated by rotation of blocks, which indicates a strong anisotropy of the blocky medium.

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Держатели документа:
RAS, Inst Computat Modelling, Siberian Branch, Krasnoyarsk 660036, Russia.

Доп.точки доступа:
Sadovskii, Vladimir M.; Sadovskaya, Oxana V.

: статья / N. V. Eremin // Сибирский журнал науки и технологий. - 2018. - Т. 19, № 2. - P346-354, DOI 10.31772/2587-6066-2018-19-2-346-354 . - ISSN 2587-6066
   Перевод заглавия: Анализ микроструктуры слоистого полимерного композиционного материала металлокомпозитного бака высокого давления

УДК

629.7

620.186

Аннотация: The microstructure of a layered polymeric composite material used in the construction of a metal composite over- wrapped pressure vessel is investigated. The purpose of this work was to evaluate the parameters characterizing the structure of a laminate polymer composite material. Due to their technological and structural features, laminated polymer composite materials have a number of operational disadvantages that lead to a reduction in the overall level of strength characteristics. From the different zones of the nine-layer composite shell of the metal composite overwrapped pressure vessel, four vertical flat samples of the composite material for the manufacture of thin sections were cut out. The method of electron-scanning microscopy was used. The analysis of the percentage confinement of fibers in the ma- trix was carried out. The structure of the layered polymeric composite material is uniform with the presence of a dis- persion of distances between the fibers. The analysis of porosity in a composite material was carried out. The analysis of the structure of composite materials with different porosity has shown that with increasing pore area and their num- ber, the strength characteristics of composite tapes and reinforcing fibers decrease. Using the “mixture rule” and “polydispersity model”, the values of the effective modulus of elasticity of the composite material are estimated. It is determined that the modulus of elasticity of the composite material in the zone of the flange of the composite shell is less than at the equator. A complex evaluation of the quality of a laminate polymer composite material used in the structure of a metal composite overwrapped pressure vessel was carried out. The obtained results of inhomogeneity of the me- chanical properties of the composite shell are necessary for design calculation of the stress-stain state of metal over- wrapped pressure vessels.
Исследована микроструктура слоистого полимерного композиционного материала, применяемого в конст- рукции металлокомпозитного бака высокого давления. Целью исследования являлась оценка параметров, ха- рактеризующих структуру слоистого полимерного композиционного материала. В связи с технологическими и конструктивными особенностями слоистые полимерные композиционные материалы имеют ряд недостат- ков при эксплуатации, которые приводят к снижению общего уровня прочностных характеристик. Из разных зон 9-слойной композитной оболочки металлокомпозитного бака высокого давления было вырезано 4 верти- кальных плоских образца композиционного материала для изготовления шлифов. Исследования проводились с использованием электронно-сканирующей микроскопии. В ходе исследований были получены изображения мик- роструктуры композиционного материала с характерным высоким уровнем контраста между волокном и матрицей. Проведен анализ процентного содержания углеродных волокон в матрице. Определено, что струк- тура слоистого полимерного композиционного материала однородна с наличием разброса расстояний между волокнами. Сравнительный анализ случайных зон микроструктуры композиционного материала указал на то, что разница в процентном содержании углеродных волокон в матрице между образцами, вырезанными с эк- ватора, небольшая, однако имеется существенная разница между образцом, вырезанным с экватора, и образ- цом, вырезанным в зоне фланца. Проведен анализ пористости в композиционном материале. Анализ структу- ры композиционных материалов с различной пористостью показал, что с ростом площади пор и их количест- ва характеристики прочности композитных лент и армирующих волокон уменьшаются. Рассчитаны значения эффективного модуля упругости композиционного материала с использованием «правила смеси» и «полидис- персной модели». Определено, что модуль упругости композиционного материала в зоне фланца композитной оболочки меньше, чем на экваторе. Проведена комплексная оценка качества слоистого полимерного компози- ционного материала, применяемого в конструкции металлокомпозитного бака высокого давления. Полученные результаты неоднородности механических свойств композитной оболочки могут быть использованы при про- ектных расчетах напряженно-деформированного состояния металлокомпозитных баков высокого давления.

РИНЦ

Держатели документа:
Institute of Computational Modeling SB RAS
Institute of Computational Technologies SB RAS

Доп.точки доступа:
Eremin, N.V.; Еремин Н.В.

/ V. M. Sadovskii, O. V. Sadovskaya // 9th Australasian Congress on Applied Mechanics, ACAM 2017 : National Committee on Applied Mechanics, 2017. - Vol. 2017-November: 9th Australasian Congress on Applied Mechanics, ACAM 2017 (27 November 2017 through 29 November 2017, ) Conference code: 135086 . -
Аннотация: Traditional rheological method is supplemented by a new element called rigid contact, which serves to take into account different resistance of materials to tension and compression. Based on this method, mathematical model describing deformation of a porous medium is constructed, which takes into account change in the resistance to external mechanical impact at a moment of collapse of pores. Parallel computational algorithm is developed for the analysis of dynamics of porous materials, accompanied by plastic deformation of skeleton and collapse of pores. This algorithm is tested on supercomputers in the problems about propagation of plane longitudinal compression shock waves and the expansion of cylindrical cavity in an infinite porous medium. The solutions of these problems are obtained in closed form in the framework of the suggested mathematical model. It is shown that, depending on the porosity of the medium and the value of the yield point, the instantaneous loading of a half-space with constant pressure leads to the formation of one or two shock waves – an elastic longitudinal wave, a plastic wave or waves of elastic or plastic compaction. Critical pressures of limit states and radii of interfaces between characteristic zones of plasticity and compaction are calculated numerically in the problem of radial expansion of cavity with sufficiently high precision. © 2017 National Committee on Applied Mechanics. All Rights Reserved.

Scopus

Держатели документа:
Institute of Computational Modelling SB RAS, Akademgorodok 50/44, Krasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Sadovskii, V. M.; Sadovskaya, O. V.

/ L. Zhang, P. M. Biesheuvel, I. I. Ryzhkov // Phys. Rev. Appl. - 2019. - Vol. 12, Is. 1. - Ст. 014039, DOI 10.1103/PhysRevApplied.12.014039. - Cited References:49. - This work is performed in the cooperation framework of Wetsus, European Centre of Excellence for Sustainable Water Technology. Wetsus is co-funded by the Dutch Ministry of Economic Affairs and Ministry of Infrastructure and Environment, the Province of Fryslan, and the Northern Netherlands Provinces. L.Z. and P.M.B. thank the participants of the research theme Advanced Water Treatment for fruitful discussions and financial support. I.R. acknowledges the support of Russian Foundation for Basic Research, Government of Krasnoyarsk Territory, Krasnoyarsk Regional Fund of Science in the frame of research project 18-48-242011 "Mathematical modelling of synthesis and ionic transport properties of conductive nanoporous membranes." I.R. also acknowledges the Dutch Science Foundation NWO for a Visitors Travel Grant No. 040.11.694. . - ISSN 2331-7019РУБ Physics, Applied

Аннотация: In this work, we develop an extended uniform potential (UP) model for a membrane nanopore by including two different charging mechanisms of the pore walls, namely by electronic charge and by chemical charge. These two charging mechanisms generally occur in polymeric membranes with conducting agents, or membranes made of conducting materials like carbon nanotubes with surface ionizable groups. The electronic charge redistributes along the pore in response to the gradient of electric potential in the pore, while the chemical charge depends on the local pH via a Langmuir-type isotherm. The extended UP model shows good agreement with experimental data for membrane potential measured at the zero-current condition. When both types of charge are present, the ratio of the electronic charge to the chemical charge can be characterized by the dimensionless number of surface groups and the dimensionless capacitance of the dielectric Stern layer. The performance of the membrane pore in converting osmotic energy from a salt concentration difference into electrical power can be improved by tuning the electronic charge.

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Держатели документа:
Wetsus, European Ctr Excellence Sustainable Water Technol, Oostergoweg 9, NL-8911 MA Leeuwarden, Netherlands.
Fed Res Ctr KSC SB RAS, Inst Computat Modelling SB RAS, Akademgorodok 50-44, Krasnoyarsk 660036, Russia.
Siberian Fed Univ, Svobodny 79, Krasnoyarsk 660041, Russia.

Доп.точки доступа:
Zhang, L.; Biesheuvel, P. M.; Ryzhkov, I. I.; Dutch Ministry of Economic Affairs and Ministry of Infrastructure and Environment; Province of Fryslan; Northern Netherlands Provinces; Russian Foundation for Basic Research, Government of Krasnoyarsk Territory; Krasnoyarsk Regional Fund of Science [18-48-242011]; Dutch Science Foundation NWO [040.11.694]

/ D. Lebedev, M. Novomlinsky, V. Kochemirovsky [et al.] // Materials. - 2020. - Vol. 13, Is. 7, DOI 10.3390/ma13071767. - Cited References:60. - This research was funded by the Russian Science Foundation, grant No 19-79-00095. . - ISSN 1996-1944РУБ Materials Science, Multidisciplinary

Аннотация: Nanocomposite membranes have been actively developed in the last decade. The involvement of nanostructures can improve the permeability, selectivity, and anti-fouling properties of a membrane for improved filtration processes. In this work, we propose a novel type of ion-selective Glass/Au composite membrane based on porous glass (PG), which combines the advantages of porous media and promising selective properties. The latter are achieved by depositing gold nanoparticles into the membrane pores by the laser-induced liquid phase chemical deposition technique. Inside the pores, gold nanoparticles with an average diameter 25 nm were formed, which was confirmed by optical and microscopic studies. To study the transport and selective properties of the PG/Au composite membrane, the potentiometric method was applied. The uniform potential model was used to determine the surface charge from the experimental data. It was found that the formation of gold nanoparticles inside membrane pores leads to an increase in the surface charge from -2.75 mC/m(2) to -5.42 mC/m(2). The methods proposed in this work allow the creation of a whole family of composite materials based on porous glasses. In this case, conceptually, the synthesis of these materials will differ only in the selection of initial precursors.

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Держатели документа:
St Petersburg State Univ, 13B Univ Skaya Emb, St Petersburg 199034, Russia.
RAS, SB, Inst Computat Modelling, Akademgorodok 50-44, Krasnoyarsk 660036, Russia.
Siberian Fed Univ, Svobodny 79, Krasnoyarsk 660041, Russia.
RAS, Grebenshchikov Inst Silicate Chem ISCh, 2 Adm Makarova Emb, St Petersburg 199155, Russia.

Доп.точки доступа:
Lebedev, Denis; Novomlinsky, Maxim; Kochemirovsky, Vladimir; Ryzhkov, Ilya; Anfimova, Irina; Panov, Maxim; Antropova, Tatyana; Russian Science FoundationRussian Science Foundation (RSF) [19-79-00095]