20 Works

Corrosion resistance and mechanical performance of steel reinforcement, before and after shot-blasting process

Ch. Apostolopoulos, Arg. Drakakaki, А.I. Rudskoi, G.Е. Коdzhaspirov & Alk. Apostolopoulos
As it is widely known, corrosion of steel reinforcement is one of the main causes of deterioration of the reinforced concrete structures. Corrosion phenomena combined with seismic loads aggravate the situation. For this reason, in the present paper, an effort is made to upgrade the performance of steel reinforcement against corrosion, using the shot blasting method. Precisely, two groups of specimens were prepared, one of which had previously been shot blasted. Afterwards, the specimens were...

Modeling microstructure evolution during thermomechanical processing and heat treatment of steels and predicting their mechanical properties

A.A. Vasilyev, D.F. Sokolov & S.F. Sokolov
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...

Nano- and microparticle aggregation: unique optical vectors for control

Alexandra G. Bezrukova & Olga L. Vlasova
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...

Natural isomers of fullerenes from C4 to C20

Alexander I. Melker & Aleksandra N. Matvienko
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...

Element-free numerical modeling with discrete gradient and its application to crystal defects

A.A. Zisman
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...


N.T. Bagraev, P.A. Golovin, V.S. Khromov, L.E. Klyachkin, A.M. Malyarenko, V.A. Mashkov, B.A. Novikov, A.P. Presnukhina, A.S. Reukov & K.B. Taranets
The characteristics of terahertz (THz) irradiation generated by a silicon nanosandwich structure under the conditions of a stabilized drain-source current are demonstrated. The frequency of irradiation arising from the quantum Faraday effect is determined by the parameters of microcavities embedded in the edge channels of a silicon nanosandwich structure confined by the negative-U centers. The obtained characteristics of a compact THz irradiation source determine the basis for highly effective medical applications.

Isomeres and isotopes of carbon

Alexander I. Melker
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...

Development of a composite hatch cover

D. Mamchits, А. Nemov, A. Karandashev, D. Büchler, R. Vasilyev & M. Ignatiev
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...

Simple Wigner-Langevin equation

Andrey L. Sanin
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.

Nuclear geometry: from hydrogen to boron

Alexander I. Melker
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...

Crystallographic orientation, delay time and mechanical constants influence on thermal fatigue strength of single - crystal nickel superalloys

A.V. Savikovskii, A.S. Semenov & L.B. Getsov
The influence of a delay time at the maximum temperature on the number of cycles for the macrocrack initiation for two thermal loading programs was investigated for two single-crystal nickel-based superalloys VIN3 and ZhS32. An analytic approximation of a delay time influence was proposed. Comparison of computational results and analytic formula on the base of constitutive equations with the experimental data was performed for considered single-crystal superalloys and showed a good accuracy. Influence of several...


A.A. Vasilyev, S.F. Sokolov Sokolov, D.F. Sokolov & N.G. Kolbasnikov
To predict the kinetics of static recrystallization and the resulting grain size in austenite of alloyed steels including additions of Nb, V, and Ti, a quantitative model is developed. Physically motivated, the model relates the activation energy of the process with that of bulk self-diffusion. The known dependence of the latter on the chemical composition of austenite solid solution, established previously, essentially simplifies the modeling. Employed empirical parameters have been fitted to relevant data covering...

Pair interaction of coaxial circular prismatic dislocation loops in elastic solids with spherical surfaces

S.A. Krasnitckii, A.M. Smirnov & M.Yu. Gutkin
In the present work, the pair interaction of coaxial circular prismatic dislocation loops (PDLs) arbitrary placed in elastic solids with free spherical surfaces is considered. The analytical solutions for the pair interaction energies of PDLs in an elastic sphere, an elastic medium with a spherical pore and a spherical layer are given in the form of double power series and illustrated by energy maps built in the space of the normalized PDL radii and axial...

Selective laser melting of copper alloy

I.A. Polozov, E.V. Borisov, V.Sh. Sufiiarov & A.A. Popovich
Additive Manufacturing (AM) of copper and its alloys is a promising way to produce parts with complex geometries without tooling. One of the AM processes is Selective Laser Melting (SLM) technology that uses a laser beam to fuse powder layers to obtain a final part. Laser processing of copper is considered to be a challenging task due to its high thermal conductivity and poor laser absorptivity. In the present work, Cu-Cr-Zr-Ti alloy powder has been...

Physical fundamentals of thermomechanical processing in ultrafine-grained metallic materials manufacturing

А.I. Rudskoi, G.Е. Коdzhaspirov, J. Kliber, Ch. Apostolopoulos & D.A. Kitaeva
The processing of metallic materials through the application Thermomechanical Processing (TMP) has now become of major importance in the world research and industrial companies. A great attention is paid to study of mechanism TMP applied to different techniques and technological processes providing ultrafine-grained state of metal materials including submicro – and nanocrystalline ones. The main development in terms of obtaining bulk metallic materials received in the recent years, various schemes of TMP of metallic materials,...

Growth of thick gallium oxide on the various substrates by halide vapor phase epitaxy

A.V. Kremleva, Sh.Sh. Sharofidinov, A.M. Smirnov, E. Podlesnov, M.V. Dorogov, M.A. Odnoblyudov, V.E. Bougrov & A.E. Romanov


A.A. Vasilyev, D.F. Sokolov, S.F. Sokolov & A.A. Zisman
Transformation kinetics of undeformed and deformed austenite during continuous cooling has been investigated on several industrial steels. Dimensions of both prior austenite grains and ferrite grains in ferrite-pearlite structures obtained for various states of parent austenite and cooling rates were determined. Based on the obtained experimental data a physically motivated model is formulated for the ferritic transformation with allowance for the effects of deformation and concurrent recovery of austenite. Under consideration is the deformation influence...

3D finite element, connected with orthogonal finite functions, in modeling and investigation of elastic homogeneous and heterogeneous material

V.L. Leontiev & I.V. Efremenkov
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...

Natural isomers of fullerenes from C30 to C40

Alexander I. Melker, Aleksandra N. Matvienko & Maria A. Krupina
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...

Natural isomers of fullerenes from C20 to C28

Alexander I. Melker & Aleksandra N. Matvienko
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...

Registration Year

  • 2020

Resource Types

  • Text


  • Peter the Great St. Petersburg Polytechnic University
  • University of Patras
  • ITMO University
  • Ioffe Institute
  • Ulyanovsk State University
  • Federal Almazov North-West Medical Research Centre
  • Institute of Problems of Mechanical Engineering
  • Technical University of Ostrava