107 Works

Shear anisotropy in Si-Cu interfaces on the atomic scale

D. Johansson, P. Hansson, A. Ahadi & S. Melin
Three dimensional molecular dynamics (MD) is used to model the mechanical response at the interface between a thin Cu coating resting on a base of Si. The copper coating is subjected to a displacement controlled shear load and the atom movements at the Si-Cu interface are monitored to investigate the effects of crystallographic anisotropy. The two crystals have the same crystallographic orientation, and two different interface normal directions are considered. The shear load is applied...

Construction of stress-strain curves for aviation materials database formation

B.E. Vasilyev, M.E. Volkov, Е.N. Bredihina & I.I. Pleshcheev
This paper discusses specific aspects of elasto-plastic behavior of various materials. It was shown, that during tensile test additional measurements are necessary for constructing stress-strain diagram. Concept of minimal stress-strain curve is presented. Issues and difficulties arising in obtaining and minimal stress-strain curve are discussed. Methods of obtaining statistically valid engineering and true stress-strain curves are introduced.


L.A. Igumnov, I.P. Markov & A. V. Boev
In this work, a boundary element method (BEM) is applied for time-harmonic analysis of three-dimensional linear piezoelectric solids. Coupled frequency domain boundary value problems of the linear theory of piezoelectricity are considered assuming zero initial conditions, in the absence of the body forces and free electric charges. The elastic and electric variables are combined into the extended vectors and tensors. Proposed boundary element approach employs regularized weakly singular frequency domain boundary integral equations (BIEs) for...

A numerical study of ballistic behaviour of ceramic metallic bi-layer armor under impact load

M.K. Khan, M.A. Iqbal, V. Bratov, N.K. Gupta & N.F. Morozov
A 3D finite element model has been developed for studying the ballistic behaviour of bi-layer ceramic-metal target plates under the impact loads induced by the projectiles of different diameter to length ratios. The bi-layer target constituted of alumina 95, as front layer, backed by aluminium alloy 2024-T3 layer, has been impacted by steel 4340 blunt and ogival nosed projectiles of diameter to length ratios, 0.5 and 1.1. The constitutive behaviour of ceramic was modelled using...

Dynamics of a frictional system, accounting for hereditary-type friction and the mobility of the vibration limiter

Leonid A. Igumnov, Vladimir S. Metrikin & Mikhail V. Grigoryev
Dynamics of a frictional system consisting of a rough body situated on a rough belt moving at a constant velocity is studied. The vibrations are limited by an elastic obstacle. The Coulomb-Hammonton dry friction characteristic is chosen, according to the hypothesis of Ishlinskiy and Kragelskiy, in the form of hereditary-type friction, where the coefficient of friction of relative rest (CFRR) is a monotone non-decreasing continuous functionof the time of relative rest at the previous analogous...

Nonlinear dynamics of serrated deformation of metals at low temperatures

G.F. Sarafanov & V.N. Perevezentsev
The mode of the serrated deformation is investigated mathematically in framework of the thermoactivation model of unstable plastic deformation in metals at low temperatures. The obtained solutions in the framework of known models, however, do not fully correspond to experimental situation, as the stress oscillations in reality are usually irregular and inhomogeneous. By this reason, additionally, the elastic correlations of neighboring deformation zones were taken into account in the model. Numerical analysis model showed that...

Asymptotics of a thermal wave in one-dimensional harmonic crystal

A.M. Krivtsov, E.A. Podolskaya & V.Yu. Shubina
An asymptotic representation is obtained at large times for the thermal wavefront propagating in a one-dimensional harmonic crystal. The propagation of thermal waves from a localized thermal perturbation and the transition zone between regions with different temperatures is considered. An explicit solution is given for a number of the simplest forms of the initial temperature distribution. It is shown that during the wave evolution, the wavefront smoothes, e.g., for a power-law dependence its degree increases...

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  • Peter the Great St. Petersburg Polytechnic University
  • N. I. Lobachevsky State University of Nizhny Novgorod
  • Institute of Problems of Mechanical Engineering
  • ITMO University
  • Ioffe Institute
  • Bauman Moscow State Technical University
  • //ror.org/02x91aj62:Peter the Great St. Petersburg Polytechnic University
  • Tver State Technical University
  • Kuban State University
  • Saint Petersburg State University