¹1(50), 2013
SUMMARIES
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 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
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 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 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 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 1(50), pp. 62-76, (Engl.).
In this paper, based on the author’s
recent year’s 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
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 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 1(50 ), pp. 89-92, (Engl.).
This paper on the basis of the theory of
kinematic wave’s 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 CARRIAGE’S WHEEL
PAIR. G. Sharashenidze, P. Kurtanidze, S. Sharashenidze. “Problems of Mechanics”. Tbilisi, 2013, ¹
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 unevenness’s. 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 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.