1(50), 2013



dynamical research of crank-piston mechanism with clearances in two kinematical pairs with consideration of additional and basic motion of mechanism. N. Davitashvili, V. Bakhshaliev. Problems of Mechanics. Tbilisi, 2013, 1(50), pp. 5-17, (Engl.).

The dynamic investigation of crank-piston mechanism with clearances in two kinematic pairs with taking into account the additional and basic motions of mechanism is stated. Are found the kinetic energies of basic and additional motions of mechanism; by application of Lagrangian second order differential equations are derived differential equations of mechanism, describing the four basic and twelve additional motions. The reduced moment, generalized forces and in the kinematic pairs with clearances - the reaction and friction forces are determined. In order to realization of obtained differential equations and expressions are given recommendations. The obtained results contribute to the reliability and durability operation of a crank-piston mechanism, as well as piston machines. 2 ill. Bibl. 16. Engl.; sum. in Russian.


research of operational characteristics (friction, wear) in kinematical pairs of cranck-piston mechanism with clearances. N. Davitashvili. Problems of Mechanics. Tbilisi, 2013, 1(50), pp. 18-39, (Engl.).

Is stated method of research of operational characteristics (friction, wear) of hinged mechanisms. In the general case are investigated friction issues in the rotating, sliding, spherical, spherical with finger and cylindrical kinematical pairs. Grounded on the analysis of wear problem in mating joints in rotary kinematical pair (shaft - bush) is investigated and calculated the wear that is caused by friction. The final aim of carried out calculations on wear is presented by assessment and adjustment tribo-matings, i.e. the assessment of cranck - piston mechanisms and piston machines reliability and durability. The obtained results also give the possibility to carry out the dynamic study of crank - piston mechanisms with clearances in kinematical pairs and consideration of total value of wear and clearance. 17 ill. Bibl. 25. Engl.; sum. in Russian.


research of operational characteristics problem (cracks formation) of crank-piston mechanism. N. Davitashvili. Problems of Mechanics. Tbilisi, 2013, 1(50), pp. 40-49, (Engl.).

In stated the analysis of cyclic strength, grounded on that is defined that research of piston machines and mechanisms with taking into account the operational characteristics (crack formation) is necessary to carry out with deep study and research of friction, wear, stiffness, physical-mechanical properties of metal structure, kinematics and thermodynamics. The processes in mating kinematical pairs with clearances of cranck-piston mechanism, grounded on that is shown that the increasing of reaction forces in hinged connections causes the shocks, vibration, oscillations and crack formation are revealed. In order to improve the reliability and durability of piston machines and mechanisms is recommended to carry out their dynamical research with taking into account the deformation of links and vibration of mechanisms. 7 ill. Bibl. 18. Engl.; sum. in Russian.


ON TRANSLATIONAL AND SPHERICAL PARALLEL MANIPULATORS WITH THREE DEGREES OF FREEDOM. Nguyen Minh Thanh, V. Glazunov, P. Laryushkin, S. Kheylo. Problems of Mechanics. Tbilisi, 2013, 1(50), pp. 50-54, (Engl.).

Translational and spherical parallel manipulators with three degrees of freedom and three kinematic chains are considered. Each kinematic chain contains five revolute joints. Structure, kinematics and workspace of these mechanisms are discussed. 3 ill. Bibl. 12. Engl., sum. In Russian.



LOCAL HEAT EXCHANGE IN COMBUSTION CHAMBER AND THE INTENSIVE HEAT STATE OF THE DIEZEL PISTON, CONVERTED INTO THE TWO-FUEL ENGINE. R. Kavtaradze, T. Natriashvili, A. Zelentsov, M. Glonti. Scientific Journal of IFToMM Problems of Mechanics, Tbilisi, 2013, 1(50), pp. 55-61, (Engl.)

The results of calculation and experimental researches of local heat exchange between the working body and piston, also intensive heat state of pistons in the main operating modes of the basic (serial) engine and its two-fuel modification with keeping of identity of conditions necessary for the results comparative analysis are given. It is ascertained that distribution of heat transfer coefficient on heat receiving pistons surfaces are characterized by great non-uniformity. Besides, at the diesel conversion into the two-fuel engines an improvement of ecological characteristics is expected as significant reduction of diesel fuel cyclic feed leads to decrease of sooth concentration in outlet (exhausted) gases. 5 ill. Bibl.9. Engl.; sum.in Russian.



GENERAL PRINCIPLES OF useful ENERGY GENERATION FROM EQUILIBRIUM ENVIRONMENT - circulation of energy and implosion AGAINST THE SECOND LAW. A. Aptsiauri. Problems of Mechanics. Tbilisi, 2013, 1(50), pp. 62-76, (Engl.).

In this paper, based on the authors recent years investigations results analysis, are stated general principles for generating of useful energy from the equilibrium environment. Is shown that the existence of transformation mechanisms and accumulation of various types of energy inside the substance creates the possibility of energy internal circulation and apparent effects of cooling and heating of the isolated environment that, in turn, gives the possibility to generate such processes, which, in essence, are contrary to the second law. Is stated the definition of implosion as processes with simultaneous decreasing of temperature and entropy. 9 ill. Bibl. 14. Engl.; sum. in Russian.


THE unsteady flow of INCOMPRESSIBLE FLUID IN A constant cross section pipes in AN AXTERNAL UNIFORM magnetic field J. Sharikadze, V. Tsutskiridze, L. Jikidze. Problems of Mechanics. Tbilisi, 2013, 1(50), pp. 77-82, (Engl.).

In this article is considered the unsteady flow of viscous incompressible electrically conducting fluid in an infinitely long pipe placed in an external uniform magnetic field perpendicular to the pipe axis. It is considered that the motion is created by applied at the initial time in constant longitudinal pressure fall. The exact general solution of problem is obtained. Bibl. 6. Engl.; sum. in Russian.


A ROD MODEL OF ELECTRIC MACHINES: MAGNETIZATION OF CORES. A. Tvalchrelidze, K. Tskhakaia. Problems of Mechanics. Tbilisi. 2013, 1(50), pp. 83-88, (Engl.).

For describing the electromechanical conversion of energy in the electrical machines there is proposed in a given article to examine the interactions of electro-conductive rods located along the axis of the machine. Within the framework of a rod model there are examined cores magnetization phenomena. Use of rheological approaches enables to adequately describe the complex magnetization processes in ferromagnetic materials of cores. 4 ill. Bibl. 5. Engl. Sum. In Russian.


ON THEORY OF INTENSIVE LOADED TRAFFIC FLOW ON LONG MOTOR ROADS. Y. Vardanyan. Problems of Mechanics. Tbilisi, 2013, 1(50 ), pp. 89-92, (Engl.).

This paper on the basis of the theory of kinematic waves propagation examines intensely loaded traffic on long roads. To study the phenomena equations of continuum mechanics have been used. Conditions have been considered under which in the traffic flow a blast wave is formed corresponding, in reality, to traffic congestion. On the basis of numerical calculations graphs have been plotted to visualize time-dependent traffic density. 3 ill. Bibl. 8. Engl.; sum. in Russian.


MATHEMATICAL ANALYSIS OF HAVING SLIDER AND OTHER IRREGULARITIES MOTION OF CARRIAGES WHEEL PAIR. G. Sharashenidze, P. Kurtanidze, S. Sharashenidze. Problems of Mechanics. Tbilisi, 2013, 1(50), pp. 93-101, (Engl.).

In the work are defined geometrical shapes of irregularities existing on the roll surfaces of carriage wheels and are given their functional dependencies. Is investigated the motion of carriage wheels related to the rail in the case of slider existing on the roll surface of wheel. The analytical expression of dependency of impact related to the rail with taking into account the slider and irregularities are obtained. The obtained results give the possibility to carry out mathematical analysis of carriage wheels for a wide range of unevennesss. 4 ill. Bibl. 8. Engl.; sum. in Russian.


EXPERIMENTAL INVESTIGATION OF TRANSPORT FLOWS TRAFFIC CONDITIONS ON HIGHWAYS OF ARMENIA. Y. Vardanyan. Problems of Mechanics. Tbilisi, 2013, 1(50 ), pp. 102-107, (Engl.).

In the article is presented method of field researches, carried out on interstate significance highways M1, M2 and M4. The investigation was carried out by video filming that is very effective for obtaining necessary information of traffic conditions of density transport flows. Except density were studied also the stream composition, speed, safety range, acceleration, number of overtaking, volume of traffic. 4 ill. Bibl. 6. Engl.; sum. in Russian.