8 Works

MULTILEVEL MODELS OF INELASTIC DEFORMATION: DETERMINATION OF STABLE LOW ANGLE BOUNDARIES

N.S. Kondratev & P.V. Trusov
The paper considers the method for determining stable low angle cell boundaries. The multilevel physical approach is applied to model inelastic deformation, using which shears are found for slip systems of the crystal. Based on these data, the density of two types of dislocation defects, which are stopped during deformation at crystallite boundaries, is introduced into consideration. The optimization problem is posed for finding sections of the boundary with reduced energy. The dependence of orientation...

Pantographic metamaterials: a view towards applications

Francesco dell'Isola, Ivan Giorgio, Luca Placidi, Mario Spagnuolo, Patrice Peyre, Corinne Dupuy, Justin Dirrenberger, Marek Pawlikowski & Leonid Igumnov
The purpose of this article is to show the basic characteristics of the so-called pantographic metamaterial. Here we underline how the microstructure provides some exotic properties and, in principle, implies the second gradient nature of this type of metamaterial. Thanks to the development of additive manufacturing technology (especially in the field of metallurgy) we are now able to produce real samples and carry out experimental measurements to validate the proposed models. In this article we...

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...

Analysis of the dynamic behavior of sand-lime and ceramic bricks

D.A. Lamzin, A.M. Bragov, A.K. Lomunov, A.Yu. Konstantinov & F. dell'Isola
The results of dynamic tests on building brick samples were analyzed using the incubation time fracture criterion. The strength and time properties of sand-lime brick and ceramic brick were under study. The tests were carried out using the classical Kolsky method and its modification - dynamic splitting. Strain rates under compression reached 2.5·103 MPa/s while stress rates under tension reached 3.5·102 GPa/s. It is noted that the strain rate affects the strength and time properties...

Use of advanced materials in protection against high-velocity impact and explosion

Aleksander V. Gerasimov, Leonid A. Igumnov & Anatoliy M. Bragov
Numerical studies of the behavior of combined barriers consisting of solid and porous materials were carried out during high-speed impact on them with thin plates. It is shown that the introduction of plates of porous materials into the composition of combined barriers can significantly reduce the amplitude of compression waves and reduce the likelihood of spall damage. Comparison of the results of numerical modeling of high-speed impact interaction processes with the experimental results of other...

A static boundary element analysis of 3D anisotropic elastic problems

L.A. Igumnov, I.P. Markov & A.V. Boev
This paper presents a direct boundary element approach for anisotropic static three-dimensional linear elastic problems. Formulation is based on the use of regularized boundary integral equation (BIE) for displacements. This BIE is weakly singular which is advantageous compared to the traditional strongly singular formulations. The displacement static fundamental solution is expressed in terms of an integral over a circumference with a unit radius. For the efficient numerical implementation of these fundamental solutions an interpolation scheme...

Investigation of strength and time properties of lime-sand brick under dynamic loading

Dmitrii A. Lamzin, Andrey K. Lomunov & Aleksander Yu. Konstantinov
The results of experimental study of mechanical properties of samples of sand-lime brick under dynamic loading are presented. The tests were carried out using the traditional Kolsky method and its modification - dynamic splitting (the so-called «Brazilian test»). The laws of change in strength and time properties of the investigated material are determined in the strain rate range of 3·102 -2.5·103 s -1 under compression and in the stress rate range of 2·101 -3·102 GPa/s...

Numerically-analytically studying fundamental solutions of 3-D dynamics of partially saturated poroelastic bodies

Leonid A. Igumnov, Andrey N. Petrov, Aleksander A. Belov, Anatoly A. Mironov, Aleksander K. Lyubimov & Denis Yu. Dianov
A mathematical model of a porous material is considered, in which an elastic skeleton and two fluid phases filling the pores are discerned. The dynamic equations are written in Laplace-type representation for unknown displacement functions of the skeleton and pore pressures of the fillers. The fundamental solutions of the defining differential equations are numerically-analytically studied. A solution in the time-domain is constructed, using the time-step method of numerically inverting Laplace transform.

Registration Year

  • 2019
    8

Resource Types

  • Text
    8

Affiliations

  • N. I. Lobachevsky State University of Nizhny Novgorod
    8
  • Warsaw University of Technology
    1
  • Arts et Métiers ParisTech
    1
  • University of L'Aquila
    1
  • Tomsk State University
    1
  • Perm National Research Polytechnic University
    1