Begell House Inc.
Nanoscience and Technology: An International Journal
NST
2572-4258
6
4
2015
MECHANICAL PROPERTIES OF CARBON FIBER-REINFORCED PLASTIC CONTAINING ADDITIONS OF FULLERENE SOOT
251-260
10.1615/NanomechanicsSciTechnolIntJ.v6.i4.10
A. V.
Artemiev
Moscow Aviation Institute (National Research University), 4 Volokolamskoe Shosse, Moscow, 125993, Russia
A. V.
Afanasiev
Moscow Aviation Institute (National Research University), 4 Volokolamskoe Highway, Moscow, 125993, Russian Federation
Lev N.
Rabinskiy
Department of Engineering Education, Moscow Aviation Institute (National
Research University), 4 Volokolamskoe Highway, Moscow, 125080,
Russian Federation
Jo Aung
Lin
Moscow Aviation Institute (National Research University), 4 Volokolamskoe Highway, Moscow, 125993, Russian Federation
carbon fiber-reinforced plastic
layered composite
mechanical properties
strength
epoxy binder
fullerene soot
The results of investigations of the microstructure and mechanical properties of carbon fiber-reinforced plastic with fullerene soot used as nanodispersed filler are presented. Samples of the composites with reinforcement scheme O2/9O4/O2, +452/−454/+452, O4, 904 were investigated. The strength and the modulus of elasticity of unidirectional samples and fillers with fiber orientation ±45 were improved by 5−20% after addition of 0.2% of the filler. The properties of composites with other fiber arrangements do not change, or may reduce to some extent. It was found that nanomodification of the binder insignificantly affected the material interlaminar shear strength and it is equal to 51 MPa. For the samples of unfilled matrix it was found the inpruvement of mechanical properties. Young modulus and ultimate tensile strength were increased by 25−30%.
MODELING THE STRESS−STRAIN BEHAVIOR OF SHUNGITE PARTICLE-FILLED RUBBERS
261-280
10.1615/NanomechanicsSciTechnolIntJ.v6.i4.20
Arseniy V.
Babaytsev
Moscow Aviation Institute (National Research University), 4 Volokolamskoe Ave.,
Moscow, А-80, GSP-3, 125993, Russia
Yu. V.
Kornev
Institute of Applied Mechanics, Russian Academy of Sciences, 7 Leningradsky Ave., Moscow, 125040, Russia
Nikolay A.
Semenov
Federal State Institution of Science Institute of Applied Mechanics of the Russian
Academy of Sciences, 7 Leningradsky Prospekt, p.1, Moscow 125040, Russia
modeling
rubber
composite
shungite
averaging methods
nanoinclusions
interfacial layer
mechanical properties
hyperelastic material
Analytical modeling of mechanical behavior of elastomeric composite samples, filled with mineral ultradisperse particles of shungite, is performed in uniaxial tension. The composite matrix is assumed to be hyperelastic, while the polymer composites are elastic or absolutely stiff. The possibility of using different models in order to specify constitutive equations of a rubber hyperelastic matrix is analyzed. Two methods of averaging for determining effective properties of composites, the Mori−Tanaka method and the double inclusion method, are compared. To obtain an approximate estimate of mechanical characteristics of nanocomposites, we assumed that inclusions in the composite are surrounded by an interfacial layer (bounded rubber), the mechanical properties of which are similar to the properties of inclusions. The results of modeling are compared with the experimental data. Based on the comparison results we obtained an approximate estimate of the thickness of the interfacial layers formed around the reinforcing inclusions, which is 15−20 nm. This is a lower-bound estimate, since we do not take into account the nonlinearity of properties of the material of interphasial regions. Among the models discussed, the best approximation to the experimental data using the smallest number of material constants can be obtained by the Ogden model combined with the Mori−Tanaka method of averaging. It is shown that for composites with microsized inclusions, as well as in the case of nanocomposite strains up to 100%, we can use the hypothesis on the linearly elastic behavior of the material in the interfacial layers that are formed around the inclusions. However, in the case of high strains of materials with nanoinclusions it is necessary to take into account the nonlinearity of properties of the interphasial regions, the volume fraction of which is significant in this case.
DEVELOPMENT OF MULTILEVEL MODELS BASED ON CRYSTAL PLASTICITY: DESCRIPTION OF GRAIN BOUNDARY SLIDING AND EVOLUTION OF GRAIN STRUCTURE
281-298
10.1615/NanomechanicsSciTechnolIntJ.v6.i4.30
Alexey I.
Shveykin
Perm National Research Polytechnic University, 29 Komsomolsky Ave., Perm,
614990, Russian Federation
E. R.
Sharifullina
Chair of Mathematical Modeling of Systems and Processes, Perm National Research Polytechnic University, 29 Komsomolskii Ave, Perm, 614990, Russia
multilevel models
crystal plasticity
grain boundary sliding
grain structure changing
grain fragmentation and breaking
In recent decades, multilevel constitutive models of polycrystalline metals and alloys have been developed intensively. These models consider the structure of the material and physical mechanisms of deformation at the crystallite level explicitly and allow the description of changes in the internal structure and of physical and mechanical properties of the material during thermomechanical processing that depend on the state of the material. Models of micro- and nanomechanics (for example, elements of molecular dynamics, dislocation dynamics) can be used either as submodels in a multilevel model of materials or can be used for clarification of its parameters. In the present paper, we present a modification of multilevel models, which was previously developed by a team of authors, by taking into account the mechanism of grain boundary sliding and changes of the grain structure as a result of breaking and fragmentation of grains. The earlier proposed two-level model of inelastic deformation of polycrystalline metals is used as a reference model. In describing the grain boundary sliding, viscoplastic shears at grain boundaries are explicitly considered with account for changes in the critical shear stresses: an increase due to intrusion as a result of intercrystalline slip, and a decrease due to increasing in energy as a result of inflow of the intragranular dislocations and diffusion processes. In order to describe the fragmentation associated with changes in mutual orientations of crystallite parts, the couple stresses that cause the fragment rotation due to nonsimultaneous dislocation sliding in it and in the neighboring fragments, are considered. The process of crystallite breaking is described by analogy with the ductile fracture. For finding the most probable plane, an optimization problem is formulated: the plane and the direction where the largest shears are accumulated are determined with account for grain elongation in the direction perpendicular to the plane. The proposed model allows the description of "regular" inelastic deformation of polycrystalline materials and deformation under the conditions of structural superplasticity (with specific effects and the state of grain structure), the transitions between these conditions of deformation (including grain structure refinement on preparation of material to superplastic deformation). The test calculation results illustrating the capacities of the proposed model are presented.
EVALUATION OF ENERGY EFFICIENCY OF THE ALUMINOTHERMIC PROCESS OF PRODUCING METAL COMPOSITE MATERIALS BY THE CRITERIA OF THE MAXIMUM SELF-HEATING TEMPERATURE AND THE AGGREGATE STATE OF OXYGEN EXCHANGE REACTION PRODUCTS
299-304
10.1615/NanomechanicsSciTechnolIntJ.v6.i4.40
Yu. A.
Abuzin
National University of Science and Technology (MISIS), 4 Leninsky Ave.,
Moscow 119049, Russia
M. M.
Karashaev
National University of Science and Technology (MISIS), 4 Leninsky Ave.,
Moscow 119049, Russia
R. A.
Sokolov
National University of Science and Technology "MISiS", 4 Leninsky Ave., Moscow, 119049, Russia
thermophysical computations
aluminothermic process
composite mate¬rials
reaction heat effect
maximum self-heating temperatures
aggregate state
As a result of theoretical calculations we obtained values of maximum temperatures of self-heating for the products of oxygen exchange reactions in aluminum oxide systems Nb−Al2O3, Mo−Al2O3, W−Al2O3, Fe−Al2O3, and Ni−Al2O3 that is caused by heat effect of these reactions. When applied to the production of composite materials by aluminothermic methods, the value of the maximum temperature of self-heating the products of oxygen exchange reaction allows evaluating the aggregate state of the components of composite materials of different systems with different aluminum oxide contents. It was established that the aluminothermic process with one of the reaction products reaching the gaseous state can be implemented. The proposed calculation methods allow evaluating self-heating of products of multicomponent metallothermic systems. The calculations showed that oxygen exchange reactions of the aluminothermic process in the discussed systems have high energy efficiency; however, the released energy is not sufficient for evaporating all reaction products and producing nanosized powder mixtures. The use of additional sources for heating the reaction products in order to obtain their complete transition to vapor is quite feasible, representing a perspective line of research for the development of nanostructured metal composite materials
SYNTHESIS OF MICRO- AND NANOSIZED BIORESORBING SILICON-SUBSTITUTED TRICALCIUM PHOSPHATES FOR BONE TISSUE ENGINEERING AND THEIR BIOLOGICAL SAFETY USING MESENCHYMAL STEM CELLS
305-317
10.1615/NanomechanicsSciTechnolIntJ.v6.i4.50
I. V.
Fadeeva
Federal State Budgetary Scientific Institution "A. A. Baikov Institute of Metallurgy and Material Science", Russian Academy of Sciences, Russia
Ya. Yu.
Filippov
Institute of Mechanics, Federal State Budgetary Higher Educational Institution "M. V. Lomonosov Moscow State University", Moscow, Russia
A. S.
Fomin
Federal State Budgetary Scientific Institution "A. A. Baikov Institute of Metallurgy and Material Science", Russian Academy of Sciences, Russia
M. E.
Shaposhnikov
Federal State Budgetary Scientific Institution "A. A. Baikov Institute of Metallurgy and Material Science", Russian Academy of Sciences, Russia
G. A.
Davydova
Federal State Budgetary Scientific Institution "Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences", Russia
O. S.
Antonova
Federal State Budgetary Scientific Institution "A. A. Baikov Institute of Metallurgy and Material Science", Russian Academy of Sciences, Russia
I. I.
Selezneva
Institute of Theoretical and Experimental Biophysics,
Russian Academy of Sciences, Pushchino, Russia
A. Yu.
Mikheev
Federal State Budgetary Scientific Institution "Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences", Russia
L. I.
Akhmetov
Federal State Budgetary Scientific Institution "G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms", Russia
S. M.
Barinov
Federal State Budgetary Scientific Institution "A. A. Baikov Institute of Metallurgy and Material Science", Russian Academy of Sciences, Russia
E. I.
Zaraisky
Institute of Applied Mechanics, Russian Academy of Sciences, Moscow, Russia
R. A.
Poltavtseva
Federal State Budgetary Institution "Academician V. I. Kulakov Scientific Center of Obstetrics, Gynecology and Perinatology", Ministry of Health
of the Russian Federation, Moscow, Russia
tricalcium phosphate ceramics
silicon-substituted
biocompatibility
Silicon-substituted tricalcium phosphates have been developed by the precipitation method and heterophase mechanic activation using tetraethoxysilan as a source of silicate ions. The phase composition was established to depend on the silicate concentration: the apatite phase is formed at 0.09 wt.% silicate and Whitlockite is formed when the silicate concentration increases 10 times − up to 0.90 wt.%. The inhomogeneity and surface roughness of the material increase with the silicate concentration. Increasing the content of silicon in synthesized TCPs increases their thermal stability. Ceramics from silicon-substituted TCPs does not manifest cytotoxicity, while the cell spreading on the material surfaces increases with the degree of surface development, displaying the maximum value for the TCP sample with Si 0.1 substitution. The TCP ceramics containing 0.9 wt.% silicate ions characterize a pronounced antibacterial activity to E. Coli strain, whereas ceramics from TCPs do not manifest antibacterial activity.
INTENSIFICATION OF MASS TRANSFER IN LAMINAR AND TURBULENT CHANNEL FLOWS BY APPLYING SUBMICRON CAVITIES ON THE CHANNEL WALL SURFACE
319-334
10.1615/NanomechanicsSciTechnolIntJ.v6.i4.60
V. A.
Aleksin
A. Ishlinsky Institute for Problems in Mechanics, Russian Academy of Sciences, 101/1 Vernadskii Ave, Moscow, 119526, Russia
A. A.
Markov
A. Ishlinsky Institute for Problems in Mechanics, Russian Academy of Sciences, 101/1 Vernadskii Ave, Moscow, 119526, Russia
tubes and cavities of submicron scale
slip
mass transfer enhancement
reduction of friction drag in pipes
A model of reduction of the friction drag in laminar and turbulent liquid and gas flows in channels by creating air-filled microcavities (micropores) on the channel walls and applying, to the surface, special coatings consisting of hydrophobic (water repellent) materials with organized structure of cavities of submicron size is suggested. It is proposed to use the slip parameters of gas phase on the surface of micropores at large Knudsen numbers. The value of the macrointensity of slip on the pipe wall has been found by applying averaging of gas microflows and gas velocity gradients in nanocavities on the basis of the model of mutually penetrating continua of the solid and gas phases. The detailed structure of gas flows in the cavities is not considered. The intensities of the slip processes are presented in dimensionless variables as functions of the coefficients of gas molecules reflection from the cavity surfaces. Calculations of the mass transfer rate were made with varied intensities of slip processes. The theoretical model makes it possible to predict the characteristics of mass transfer intensification both at small and large Reynolds numbers. The possibilities of applying the differential model of turbulence in the case of simultaneous action of two factors − the high intensity of turbulence in the incoming flow and slip on the wall − have been established.
2015 INDEX
335-342
10.1615/NanomechanicsSciTechnolIntJ.v6.i4.70