A. E. Tsibulko, E. A. Romanenko (PJSC «NKZM», Kramatorsk, Ukraine)

On the question of three energy concepts of breaking the strength of materials in a complex stress state

hree energy concepts of a possible violation of the strength of materials under a complex stress state and the criteria of the limiting state proposed on their basis are considered.
Keywords: complex stress state; specific potential energy of deformation; mail stress; equivalent stress.

A. V. Platonov, N. P. Yampurin, M. A. Kumaneev, N. A. Yankavtseva, K. A. Shchegletov, E. S. Korshunov (Arzamas Polytechnic Institute, a branch of the Nizhny Novgorod State Technical University named after R. E. Alekseev, Arzamas)

Simulation modeling technique in the research of device design for «Lathe unclamp fixture»
Part 1. Optimization of design parameters

The research task is to optimize the design of the «Lathe unclamp fixture» and to reveal  the influence degree of the device clamping forces on its hardness and stability of the processed workpiece, which is located on unclamp fixture up the pre-processed central hole. The research was carried out using the innovative modeling method in the T-FlexCAD design system. The practical application of the proposed research method is advisable in the calculation analysis of technological processes of mechanical turning of parts using such devices.
Keywords: research of technological processes; simulation modeling technique; unclamp fixture; deployment through the internal diameter; safety factor; turning treatment; device design optimization; pneumatic device drive.

S. A. Gubar, V. G. Komkov, G. G. Voskresensky (Pacific State University, Khabarovsk)

Comparative assessment of the sensitivity of cylindrical gears with arched teeth to errors in the relative position of the wheels

The article evaluates the sensitivity of cylindrical gears with arched teeth to errors in the relative position of gears. Sensitivity is estimated by the amount of displacement of the contact point from the nominal position. The considered transmission is compared with a cylindrical transmission with a barrel-shaped modification of the teeth. it is shown that for comparable parameters, a transmission with arched teeth may have a lower sensitivity to skew and non-parallelism of the gear axes.
Keywords: cylindrical gears; arched teeth; barrel modification; skew; non-parallelism of axes.

A. N. Epifanov (JSC NPO Energomash named after academician V. P. Glushko, Khimki); E. G. Demyanenko (Samara National Research University named after academician S. P. Korolev, Samara)

Simulation of forming process of thin-walled axisymmetric shells in Pam-Stamp 2G and Ansys 18.2 software products

In this paper, we consider a method of flanging and molding to obtain thin-walled axisymmetric shells with minimal wall thickness. Computer simulation was performed in the Pam-Stamp 2G (ESI Group) and Ansys 18.2 software products to analyze and obtain the most favorable process parameters. Conclusions are drawn on the results.
Keywords: thickness; flanging; forming; stamp; conical part; simulation.

Yu. N. Loginov (The Ural Federal University named after the first President of Russia B. N. Yeltsin, Institute of Physics of Metals named after M. N. Mikheev Ural Branch of the Russian Academy of Sciences, Ekateriburg); A. S. Ovchinnikov (PJSC «Revda non-ferrous metals processing plant», Revda)

Modeling the behavior of metal near the surface of the backpad

The results of finite element simulation in the ABAQUS software module of the behavior of the metal near the surface of the backpad during relief execution of its working surface are presented. The calculations of the distribution of the strains are performed. It is concluded that there are hard zones in the depressions of the relief, which impede the radial sliding of the metal and reduce the size of the press-weights.
Keywords: extrusion; backpad; press-weigher; plastic deformation; finite element method; ABAQUS software module.

Naeim David Hurmuz (Higher School of Economics, Moscow)

Formation of the metallurgical industry in Syria and Iraq: problems and prospects

The article examines the current situation in the metallurgical industry in Syria and Iraq, as a strategically important industry, and highlights other key issues facing the restoration of centralized, effective and legitimate functions of the state. Particular attention is paid to the need to achieve a balance in governance mechanisms that can restore links at the local and national levels and effectively manage the allocation of resources. The article emphasizes the need for a holistic approach to restoring effective and legitimate public administration structures. The analysis aims to understand the type of public administration reforms in Syria and Iraq over the past decade.
Keywords: public administration; Syria; Iraq; administrative reform; public sector; developing countries.

V. A. Gnevasheva (Institute for Demographical Research, Branch of the Federal Center of Theoretical and Applied Sociology, Russian Academy of Sciences, Moscow; Center for Family and Demography of the Academy of Sciences of the Republic of Tatarstan, Kazan); Ch. I. Ildarhanova (Center for Family and Demography of the Academy of Sciences of the Republic of Tatarstan, Kazan)

Migration flows of the municipal regions of the Republic of Tatarstan: Potential and threats of regional demographic development

The article is aimed at studying a separate subject of the Russian Federation – the Republic of Tatarstan in terms of assessing regional migration flows. The study sets the task of assessing and describing the nature of external and internal migration in the regions of the Republic, determining the main factors; affecting the change in the characteristics of migration flows; determine the socio-economic prerequisites for migration and justify the degree of influence of migration on the demographic indicators of the region. The study used methods of regression analysis, econometric methods for evaluating empirical data. The information base of the study is the data of field and statistical estimates of the main indicators of the regions of the Republic. The study allows us to identify a number of significant trends in certain regions of the Republic, to determine the degree of influence of migration flows on the general demographic situation. The main factor inducing migration was determined to be economic, while the main consequence of migration is mainly on the social factors of the development of society, especially on the transformation of social networks in terms of family and marriage. The article presents a grouping of regions of the Republic in accordance with trends in the main indicators of migration in comparison with demographic indicators. In conclusion, the mechanism of a possible change in the current demographic situation under the influence of migration towards the development of positive trends in the transformation of society towards the stability of social interactions on the basis of strengthening the family is presented.
Keywords: migration; demographic indicators; regional development; compensatory effect of migration; regression analysis.