41 Works

The mechanical properties improvement of thermoplastics-based fiber metal laminates

Dmitry Goncharenko, Ilya Kobykhno, Elizaveta Bobrynina & Oleg Tolochko
This study investigated the possibility of increasing the fiber metal laminates mechanical properties by improving the impregnation quality due to the addition of a different number of layers of polymer film on the prepreg-metal interface. Specimens were made based on two thermoplastic polymers (polyamide-6 and polypropylene), glass fibers (E-glass), and aluminum alloy (AlMg6) by hot pressing. The theoretical calculation was performed for the tensile strength according to the rule of mixtures. The dependences of tensile...

Deformation mechanism of bimodal metal-graphene composites with nanotwinned structure

N.V. Skiba
The theoretical model is suggested which describes micromechanisms of plastic deformation in bimodal metal-graphene composite consisting of large grains embedded into nanocrystalline/ultrafine-grained metal-matrix reinforced by graphene inclusions. In the framework of the model, lattice dislocation slip and grain boundary sliding has occurred in nanocrystalline/ultrafine-grained matrix, and lattice dislocation slip and migration of twin boundaries are realized in large grains with a nanotwinned structure providing the plastic deformation of bimodal metal-graphene composite. With this assumption, the...

Modeling of carbides and copper particles precipitation during tempering of bainitic-martensitic Cr-Mo-V-Cu steels

A.A. Vasilyev, S.F. Sokolov & D.F. Sokolov
The paper represents a model for the tempering effects on quenched bainitic-martensitic steels that describes both the recovery and precipitation phenomena. The latter involves various carbides (Fe3C, V4C3, Mo2C, Cr7C3) and particles of pure Cu. Thermodynamic driving forces in the nucleation of the considered particles have been calculated using empirical formulas obtained with the Thermo-Calc software. The predicted formation kinetics for the considered carbides and Cu particles complies well with relevant experimental data.

Frequency-Dependent Dynamic Characteristics of the Soil Foundation

Aleksey Shokin & Daniil Semenov

Teaching English as a Language for Mechanical Engineering

Eduard Krylov, Liudmila Khalyapina & Alfred Nordmann
Engineering education usually includes the acquisition of a foreign language for a transnational professional discourse. Engineering education also involves the acquisition of competencies to compose functional technical systems from component parts. This paper provides a conceptual and empirical exploration of a synergistic effect between these two learning processes. It proposes that engineering education draw upon and incorporates this synergy. A pilot training course confirms that this leads to a faster development of the overall engineering...

NUCLEAR GEOMETRY: FROM NITROGEN TO NEON

Alexander I. Melker
The nuclear geometry was developed by analogy with the fullerene geometry. On the basis of this geometric approach, it was possible to design the structure of nitrogen, oxygen, fluorine and neon isomers and their isotopes, which can be obtained by means of nuclear synthesis. The most stable nuclei can be classed into two groups: basic nuclei having equal number of protons and neutrons and isotopes having one or two more neutrons. The latter ensure their...

Исследование структуры и элементного состава поверхности металла после финишного плазменного упрочнения

Павел Абрамович Тополянский, Сергей Александрович Ермаков & Андрей Павлович Тополянский
Рассмотрена актуальность изучения структуры и элементного состава тонкопленочных покрытий для прогнозирования эффективности повышения долговечности деталей. Приведены известные механизмы упрочнения металла при создании антифрикционных материалов, обеспечивающих минимальные коэффициент трения, длительность приработки, тепловыделение при трении и параметры износа, и дисперсионно-упрочненных наночастицами материалов, повышающих прочностные характеристики. Рассмотрены отдельные аспекты технологии финишного плазменного упрочнения путем нанесения покрытий на финишной стадии изготовления деталей при их температуре нагрева менее 150 °С и неизменности исходных параметров шероховатости. Результаты растровой электронной микроскопии подтвердили...

Effect of the specimen size on necking development in metals and alloys during superplastic deformation

A.G. Sheinerman
A model is proposed that describes the development of individual and multiple necks in superplastically deformed materials. Within the model, the examined samples have the form of round bars and are subjected to tensile superplastic deformation without strain hardening. It is demonstrated that neck development and necking-induced failure occur faster with a decrease in strain rate sensitivity and/or an increase in the fraction of the sample length occupied by necks. This means that high values...

ON BUCKLING INDUCED BY A CHEMICAL REACTION

V.O. Shtegman, A.V. Morozov Morozov, A.B. Freidin & W.H. Müller
This study is concerned with the modeling of plate buckling induced by a chemical reaction and is inspired by the observation that buckling may be a mechanism of stress relaxation in Si-based anodes in Li-ion batteries. A chemical reaction is localized at a sharp interface and accompanied by transformation strains, which produce internal stresses. If external supports restrict the deformation of the plate, buckling may occur. At the same time, mechanical stresses affect the kinetics...

In the Beginning was the Word

Alfred Nordmann & Daria Bylieva
The problem of modernity haunts the Western tradition of philosophy and moves us from disenchantment and disempowerment of the word to its reenchantment. If critical reasoning exorcised the magic power of the word, technological achievements of control reinstated it. More straightforwardly, perhaps, Russian thought traditionally viewed the word as a "technical" or "magical" artifact capable of changing the world. In the beginning was God‘s word but are also the words which open the world of...

Vertical Transport Systems for High-Rise Buildings

Марина Нафикова, Marina Gravit, Kirill Kuzenkov & Ivan Dmitriev

A model for annealing-induced hardening in ultrafine-grained metals

A.G. Sheinerman & S.A. Krasnitckii
We suggest a model, which describes the effect of grain boundary relaxation on the annealing-induced hardening in ultrafine-grained metals. Within the model, grain boundary relaxation during annealing is accompanied by a decrease in the number of grain boundary dislocation sources. The exhaustion of easily activated grain boundary dislocation sources results in the activation of harder grain boundary dislocation sources and/or repetitive action of the same dislocation sources. This gives rise to an increase in the...

THE NATURE OF DC CONDUCTIVITY AND STRUCTURAL FEATURES OF GLASSES OF THE Ag – As – Se SYSTEM AS MATERIALS FOR PHOTONICS AND INTEGRAL OPTICS

E.V. Bochagina, V.A. Klinkov, V.A. Markov, V.V. Polyakova & I.A. Sokolov
The physical and chemical properties (density, microhardness, thermal effects, elastic modulus, dc conductivity, and the transfer number of silver ions) of glasses of the As – Se – Ag system along the AsSe – Ag and AsSe1.5 – Ag sections were investigated. The transfer numbers of Ag+ ions were determined by a direct method; from their changes, it was found that the glasses of the investigated sections have mixed ion-electronic conductivity. The threshold concentration of...

The Automated Expert Workplace as a Tool for Technological Support for Forensic Expert Activities

Igor Latyshov
The forensic institutions of the Russian Federation draw on the advanced achievements of science and technology to account for the state of modern crime, the methods of committing and concealing crimes. In order to achieve this efficiency at the present stage, issues of technological support of forensic expert activity are of particular relevance. Based on an analysis of the scientific knowledge-base, it is noted that for the successful solution of tasks through the effective use...

SSRT method: application to studying the mechanism of stress corrosion cracking in steels and alloys (overview)

A.А. Kharkov , A.A. Alkhimenko, N.O. Shaposhnikov &  E.L.  Alekseeva
The paper briefly describes the slow strain rate testing (SSRT) method used for steels and alloys, considering the stress and strain criteria for assessing the sensitivity of materials to stress corrosion cracking (SCC). We pointed out the clear benefits of the SSRT method over static SCC testing. We reviewed the modern theories of the main possible mechanisms of SCC, typically including alternating stages of anodic dissolution and hydrogen embrittlement during the initiation and propagation of...

Technology and Language in Tattoos

Daria Ozerova & Alisher Serikov
This study identifies graphic features of words that are used in tattoos. Our interest in this type of name tattoos is based on the fact that words have a great significance in a person's life. The article presents the history of the origin of tattoos from ancient times, the geography of tattoos, and also describes in detail the methods of ancient tattooing techniques. It moves on to the main task of analyzing the relationship between...

Registration Year

  • 2021
    41

Resource Types

  • Text
    41

Affiliations

  • Peter the Great St. Petersburg Polytechnic University
    41
  • St Petersburg University
    2
  • Institute of Problems of Mechanical Engineering
    2
  • TU Darmstadt
    2
  • Volgograd Academy of the Russian Internal Affairs Ministry
    1
  • Graz University of Technology
    1
  • Saint Petersburg Mining University
    1
  • Izhevsk State Technical University
    1
  • Satbayev University
    1
  • Charles University
    1