https://www.elibrary.ru/title_about_new.asp?i
1605-8119
Materials physics and mechanics
45
1
2020
1-199
RAR
RUS
1-7
Zisman
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Element-free numerical modeling with discrete gradient and its application to crystal defects
The gradient operation has been extended to discrete data in terms of nodal coordinates. On this ground, the nodal strains and related stresses are expressed directly in terms of nodal displacements and the stress divergence in terms of nodal stresses. To make use of truly discrete modeling in computational solid mechanics, the stress balance equation is formulated. For a case study, the latter is applied to an edge dislocation where atom positions of a dislocated crystal are taken for nodal points. Both the resulting stress level at the dislocation core close to the theoretical strength and the corresponding core dimensions prove to be realistic physically, whereas the long-range nodal stresses asymptotically approach the virtual continuous fields known in an analytical form.
10.18720/MPM.4512020_1
discrete gradient
edge dislocation
element-free model
shape function
stress balance
https://mpm.spbstu.ru/article/2020.78.1/
1-Alexander-A_-Zisman.pdf
RAR
RUS
8-19
Vasilyev
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Sokolov
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Sokolov
Peter the Great St. Peresburg Polytechnic University
St.Petersburg, Russia
Modeling microstructure evolution during thermomechanical processing and heat treatment of steels and predicting their mechanical properties
An integral computer model/program AusEvol Pro was developed to describe the evolution of steel microstructure during thermomechanical processing (hot rolling, forging), as well as subsequent heat treatment (normalization, tempering), and to evaluate the final mechanical properties (yield stress, tensile stress, elongation), hardness and impact toughness. The program implements a set of physically based models that allow quantitative description of all significant processes of steel structure formation with account of the effects of chemical composition both during thermomechanical processing and heat treatment. Calculations of the final mechanical properties are carried out using the developed models that take into account all physically meaningful contributions. The models created are verified both on the extensive database of our own experimental studies and on reliable data from literature for steels of various chemical compositions.
10.18720/MPM.4512020_2
heat treatment
mechanical property
microstructure
modeling
steel
thermomechanical processing
https://mpm.spbstu.ru/article/2020.78.2/
2-A_A_-Vasilyev-et-al.pdf
RAR
RUS
20-30
Mamchits
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Nemov
Alexander
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Karandashev
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Büchler
Baltico GmbH
Hohen Luckow, Germany
Vasilyev
Baltico GmbH
Hohen Luckow, Germany
Ignatiev
Baltico GmbH
Hohen Luckow, Germany
Development of a composite hatch cover
Two designs of a composite marine hatch cover were developed on the basis of the design of a steel one. One of the proposed designs features composite structure made by means of manual lay-up technology, and the other one is based on a truss composite structure which can be produced by rod winding process. Selection of the most rational materials and design parameters was carried out on the basis of finite element simulations and use of parametric optimization methods. Results reveal the possibility of weight reduction by means of using composites in the hatch cover, which is associated, however, with a comparatively high cost.
10.18720/MPM.4512020_3
composite material
finite element analysis
hatch cover
parametric optimization
sandwich panel
https://mpm.spbstu.ru/article/2020.78.3/
3-D_-Mamchits%2C-A_-Nemov%2C-A_-Karandashev%2C-D_-Buechler%2C-R_-Vasilyev%2C-M_-Ignatiev(1).pdf
RAR
RUS
31-37
Leontiev
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Efremenkov
Ulyanovsk State University
Ulyanovsk, Russia
3D finite element, connected with orthogonal finite functions, in modeling and investigation of elastic homogeneous and heterogeneous materials
A novel 2D finite element (FE) associated with orthogonal finite functions (OFF, orthogonal splines) was developed for the ANSYS software and was tested early. The expansion of this method is presented here. The novel 3D FE, connected with 3D OFF is proposed for modeling and investigation of the stress-strain state of homogeneous and heterogeneous elastic bodies. The accuracy of the solutions obtained with this 3D FE is as high as for the classic ANSYS 3D FE. The developed 3D FE requires significantly less computational time; the winning of computational time increases with the amount of FE in a model.
10.18720/MPM.4512020_4
3D finite element
homogeneous material
heterogeneous materials
orthogonal finite function
shape function
https://mpm.spbstu.ru/article/2020.78.4/
4-V_L_-Leontiev-and-I_V_-Efremenkov(1).pdf
RAR
RUS
38-48
Melker
A.I.
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Matveenko
V.P.
Institute of Continuous Media Mechanics (RAS)
Perm, Russia
Natural isomers of fullerenes from C4 to C20
We have systematized possible ways of forming the isomers of mini-fullerenes, namely elementary fullerenes: tetrahedron C4, triangular prism C6, cube C8, pentagonal prism C10, hexagonal prism C12, as well as their derivatives, which were obtained by joining elementary fullerenes. Combined with the graph analysis, this approach allows obtain a clear knowledge of their structure. Among them there are barrel-shaped fullerenes: C12, C16, C20; tetrahedral ones C12 and C16; bi-shamrocks C14 and C18, bipyramids C14 and C18; regular and irregular dodecahedrons C20 as well as intermediate compounds. The three simplest elementary fullerenes, C4, C6, C8; have only electronic isomers and no space atomic isomers at all. After a cube, the next in size carbon fullerene C10 is a pentagonal prism. We have designed an isomer of it by fusion of a tetrahedron and a triangular prism. For the pentagonal prism shape fullerene the energy lies in the range from 974 to 2464 kJ/mol, for the hybrid of a tetrahedron and a triangular prism does in the range from 1396 to 2433 kJ/mol; it depends both on the number of single and double bonds as well as on their position in space. Fullerene of twelve carbon atoms C12 produces four isomers: a hexagonal prism, a barrel-shape fullerene, a truncated tetrahedron and a tetra-penta octahedron. They have different energies depending on the number of single and double bonds and their position in space. In a like manner other fullerenes studied, C14, C16, C18 and C20, have two or three isomers with different energies.
10.18720/MPM.4512020_5
atomic isomer
electronic isomer
energy
fullerene
fusion reaction
graph representation
growth
periodic system
https://mpm.spbstu.ru/article/2020.78.5/
5-Alexander-I_-Melker-and-Aleksandra-N_-Matvienko(1).pdf
RAR
RUS
49-59
Melker
A.I.
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Matveenko
V.P.
Institute of Continuous Media Mechanics (RAS)
Perm, Russia
Natural isomers of fullerenes from C20 to C28
We have systematized possible ways of forming the isomers of midi-fullerenes, namely C22, C24, C26 and C28. There are three the most natural mechanisms of their obtaining: embedding carbon dimers into initial fullerenes; fusion of carbon cupolas having the same symmetry; fusion of fullerenes having compatible symmetry. The minimum energy fullerenes are obtained through the use of the first mechanism. It is worth noting that these fullerenes conserve the topological three-fold symmetry. At the same time the graph representation shows the change of symmetry from three-fold symmetry to six-fold one. Combined with the graph analysis, this geometric modeling allows obtain a clear knowledge of the structure of the fullerenes formed.
10.18720/MPM.4512020_6
atomic isomer
electronic isomer
energy
fullerene
fusion reaction
graph representation
growth
periodic system
https://mpm.spbstu.ru/article/2020.78.6/
6-Alexander-I_-Melker-and-Aleksandra-N_-Matvienko(1).pdf
RAR
RUS
60-78
Melker
A.I.
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Matveenko
V.P.
Institute of Continuous Media Mechanics (RAS)
Perm, Russia
Krupina
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Natural isomers of fullerenes from C30 to C40
We have systematized possible ways of forming the isomers of midi-fullerenes, namely C30, C32, C34 C36, C38 and C40. Similar to the isomers of midi-fullerenes from C20 to C28, there are three the most natural mechanisms of their formation: 1) Embedding carbon dimers into initial fullerenes; 2) Fusion of carbon cupolas having the same symmetry; and 3) Fusion of fullerenes having compatible symmetry. The energies of the fullerenes calculated through the use of molecular mechanics are presented together with their graphs. It is found that in the majority of cases the minimum-energy fullerenes are those, having perfect and topological three-fold symmetries.
10.18720/MPM.4512020_7
atomic isomer
dimer embedding
energy
fullerene
fusion reaction
graph representation
growth
periodic system
self-organization
symmetry
topological symmetry
https://mpm.spbstu.ru/article/2020.78.7/
7-Alexander-I_-Melker%2C-Aleksandra-N_-Matvienko-and-Maria-A_-Krupina(1).pdf
RAR
RUS
79-86
Sánchez-Bernabe
Department of Mathematics, U A M
Mexico
Towards a periodic pattern in classical and nonclassical fullerenes with tetrahedral structure
We have considered the following classical fullerenes: C40 C84 and C92. All of them have tetrahedral symmetry. The nonclassical fullerenes C64 and C76 were proposed earlier. Now, we have outlined a constructive process to obtain both fullerenes. The Table obtained earlier is complemented with four nonclassical fullerenes C52, C60, C88, and C100. The mass difference Δm between the numbers of carbon atoms of the fullerenes forms the sequence: 8, 4, 12, 8, 4, 12, 8, 4, 12. Its periodicity has no gaps as before.
10.18720/MPM.4512020_8
isolated pentagon rule
nonclassical fullerene
Schlegel diagram
tetrahedral symmetry
https://mpm.spbstu.ru/article/2020.78.8/
8-F_J_-Sanchez-Bernabe(1).pdf
RAR
RUS
87-95
Bezrukova
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Vlasova
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Nano- and microparticle aggregation: unique optical vectors for control
The multiparameter analysis of simultaneous optical data for systems of nano- and/or micro-particles (3D disperse systems, dispersions, colloids, ensembles with the average diameter less than 10 micrometers) can be presented as the system characteristics characterized by N-dimensional unique vectors of optical parameters that can elucidate changes in the state of system particles. The application of ND unique optical vector approach is shown for several biomedical dispersions at the processes of aggregation. This approach can serve as the online control platform for the management of technological processes with 3D disperse systems.
10.18720/MPM.4512020_9
absorbance
aggregation
biomedical nano and micro particle
light scattering
ND optical vector
3D disperse system
https://mpm.spbstu.ru/article/2020.78.9/
9-Alexandra-G-Bezrukova-and-Olga-L-Vlasova(1).pdf
RAR
RUS
96-100
Sanin
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Simple Wigner-Langevin equation
A new dynamical equation is derived by substituting the Schrödinger-LangevinKostin equation into the definition for the Wigner function, it can be called the quantumclassical Wigner-Langevin equation. The proposed equation contains partial derivatives for time and phase space variables of the Wigner function, its coefficients are spatial derivatives of potentials that take into account friction, white noise and external influence. The transition to the classical regime of motion is also discussed.
10.18720/MPM.4512020_10
phase space
Wigner-Langevin
quantum-to-classical transition
friction
white noise
https://mpm.spbstu.ru/article/2020.78.10/
10-Andrey-L_-Sanin(1).pdf
RAR
RUS
101-103
Sery
A. S. Pushkin Brest State University
Brest, Republic of Belarus
Influence of resonance Compton scattering in a magnetic field on rotation of the polarization plane of photons
The solution of the problem of the value of rotation of photon polarization plane in totally spin-polarized electron gas in quantizing magnetic field is obtained. The second order perturbation theory on electromagnetic coupling is considered using modified Gell-Mann– Goldberger–Thirring dispersion relationship and optical theorem. Approximate formula obtained by Fomin and Kholodov for resonance Compton scattering cross-section is used in calculation.
10.18720/MPM.4512020_11
Baryshevsky–Luboshits effect
electron gas
quantizing magnetic field
spin polarization of electrons
https://mpm.spbstu.ru/article/2020.78.11/
11-Alexey-I_-Sery(1).pdf
RAR
RUS
104-131
Ivashkevich
B.I. Stepanov Institute of Physics
Minsk, Belarus
Ovsiyuk
Mozyr State Pedagogical University
Mozyr, Belarus
Kisel
Belarus State University of Informatics and Radio-electronics
Minsk, Republic of Belarus
Red'kov
B.I. Stepanov Institute of Physics
Minsk, Belarus
Spinor Maxwell equations in Riemannian space-time and the geometrical modeling of constitutive relations in electrodynamics
It is known that vacuum Maxwell equations being considered on the background of any pseudo-Riemannin space-time may be interpreted as Maxwell equations in Minkowski space but specified in some effective medium, which constitutive relations are determined by metric of the curved space-time. In that context, we have considered de Sitter, anti de Sitter, and Schwarzschild models. Also we have studied hyperbolic Lobachevsky and spherical Riemann models, parameterized by coordinates with spherical or cylindric symmetry. We have proved that in all the examined cases, effective tensors and of electric permittivity and magnetic permeability obey one the same condition: . Expressions for tensors and are simple, but this simplicity is misleading. For each curved space-time model we are to solve Maxwell equations separately and anew. We have constructed the solutions, applying Maxwell equations in spinor form.
10.18720/MPM.4512020_12
constitutive relations
electrodynamics
geometrical modeling
Maxwell equations
Riemannian space-time
spherical and cylindric symmetry
spinor formalism
https://mpm.spbstu.ru/article/2020.78.12/
12-A_V_-Ivashkevich%2C-E_M_-Ovsiyuk%2C-V_V_-Kisel%2C-V_M_-Red%E2%80%99kov(1).pdf
RAR
RUS
132-149
Melker
A.I.
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Nuclear geometry: from hydrogen to boron
Possible ways of nuclear synthesis in the range from hydrogen to boron are studied. The geometric model of these nuclei is suggested. The basis for this model is the analogy between tetrahedral fullerene C4 and helium 2He4 . It is assumed that a nucleus of helium 2He4 has the form of a tetrahedron, where: 1) All the apices are equivalent and therefore they are protons, 2) Each neutron in a nucleus decomposes into a proton and three negatively charged particles having the charge ⅓ of that of an electron, 3) Interaction of the negative particles creates a special electronic pattern, which symmetry does not coincide with that of protons one, but determines it. On the basis of the postulates, the structure of other nuclei has been designed using geometric modeling. For hydrogen, deuterium, tritium and helium 3, a point, a linear and a plane structure respectively have been obtained. Helium 4 has tetrahedral symmetry. Then there was transition from three-fold symmetry prisms (lithium 6 and 7) to five-fold symmetry (boron 10 and 11) through four-fold one (beryllium 8, 9, 10). The nuclear electron patterns are more complex; their polyhedrons resemble the electron pairs arrangement at the valence shells of molecules.
10.18720/MPM.4512020_13
beryllium
boron
deuterium
graph representation
helium
hydrogen
lithium
nuclear electron
nuclear geometry
https://mpm.spbstu.ru/article/2020.78.13/
13-Alexander-I_-Melker(1).pdf
RAR
RUS
150-166
Melker
A.I.
Peter the Great St. Petersburg Polytechnic University
St.Petersburg, Russia
Nuclear isomers and isotopes of carbon
The nuclear geometry has been developed by analogy with the fullerene geometry. On the base of this geometric approach, the structure of carbon isomers and isotopes, which can be obtained by means of nuclear synthesis, has been designed. The mechanisms of possible nuclear reaction are discussed. Carbon is an unusual element. It has four isomers of different symmetry: three-fold, six-fold and tetrahedral ones, two being stable and one halfstable. The isotopes of carbon inherit the structure of the isomers.
10.18720/MPM.4512020_14
carbon
graph representation
isomer
isotope
nuclear electron
nuclear geometry
nuclear reaction
nuclear synthesis
https://mpm.spbstu.ru/article/2020.78.14/
14-Alexander-I_-Melker(1).pdf