Sessions 2015-2016

The paper presents the results of the molecular dymanics (MD) simulations for deformation and destruction of a graphene sheet with a crack. The dependence between the stress and strain in graphene sheet is analyzed. The comparasion between the results for the case with deformation along the "armchair" direction and for the case with deformation along the "zigzag" direction is provided.

Papers on «Functional properties of Ni-Fe-Ga single crystal shape memory alloy are analyzed. One-way and two-way shape memory effects are studied for Ni-Fe-Ga alloy subjected to pre-deformation.

Development of cosmic technologies causes necessity of investigation of the Earth magnetosphere, in particular modeling of its structure and dynamics. This work presents an attempt of the analysis and comparison of results of two modelling methods, namely adaptive modeling and global MHD, of the MHD substorm. The good agreement of both methods was shown.

Research of physicomechanical parameters and charts tension/deformation is conducted in case of stretching of technical AD1 aluminum with different grain size, and also influence of the sizes of a sample on results of stretching is studied.

The method for determination of the composition of thermally ionized monatomic gas is considered. Gas is supposed to be highly rarefied. The proposed method permits reducing the calculation of the equilibrium composition to solution of one algebraic equation. The temperature dependence of equilibrium atoms, ions and electrons of ionized hydrogen is obtained.

A thin elastic annular plate under 2 radial point tensile loads is considered. It is shown that compression areas develop under tensile loading, which may lead to buckling. The Timoshenko energy method is applied to solve the buckling problem. The critical load value and buckling mode are found.

Mechanical properties of amorphous Ti50Ni25Cu25 thin ribbons are examined during tension. Dependence of properties of crytallined shape memory alloy in austenitic and martensitic phases on crystallization parameters is explored.

The spall fracture is the most popular method to research intensive tensile loads. The material's behaviour under different loads was studied by data processing. Structural time criterion was used to find dynamic strength parameters and to explain temporal effects of fracture.

Influence of end plates on the airflow around rectangular plate is studied experimentally. The drag force coefficient, the base pressure coefficient and dimension of recirculating region are obtained for two plates with and without end plates.

Mathematical model of a wind-powered station consisting of a synchronous generator, which rotates by the propeller is considered. The rotating moment on the part of the propeller is proportional to the square of velocity of incoming air stream. Two problems are considered: i) the synchronous generator working with the network of unlimited power of alternating current and ii) the synchronous generator working with actively inductive load. The stability conditions for two cases are found.

The problem of strength assessment of an interface between tile and base is considered. The state of stress and strain in vicinity of reentrant corner at the edge of the interface tile/base is described by asymptotic formulas with unknown stress intensity factors.

In the framework of this approach the strength of the joint of beryllium tiles of the First Wall mockup of Tokamak under stationary heat flux action is investigated. The results obtained match qualitatively the results of known experiments.

Also two-dimensional model of thin elastic patch with predefined approximation of displacements across the thickness is proposed. The stresses on the contour of an interface between the patch and the base are finite, but contour forces take place, which allows formulating of the strength criterion in the terms of contour forces.

With the help of known experimental data ultimate loads for the single lap joint specimen have been evaluated as a function of overlap length. The calculations based on both asymptotic formulas of reentrant corner and the model of thin elastic patch provide close results.

The paper sets out the necessary information about the variational principles of conformal mappings based on the works of academician M.A. Lavrentiev (11.19.1900 - 15.10.1980). On the basis of this principle, the plane problems of hydromechanics and hydroelasticity solved effectively.
We present some historical data. The solution for the plane problem of a potential flow around a hard body close to circular is presented. The concept of "proximity to the circular contour" is formalized. The application of variational principles of conformal mappings to problems hydroelasticity is discussed.