¹2(43), 2011
SUMMARIES
dynamical research of planar closed chain manipulators
with elastic links. N.
Davitashvili. “Problems of
Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 5-13, (Engl.).
Is
given the dynamic investigation of planar manipulator with two degrees of
freedom, taking into account the elasticity of links, kinematic chain of that
is closed. At the first stage of the study is given the description of links
elastic deformation determining method. Further are defined: reduced
coefficient of stiffness of manipulator, and kinetic and potential energies.
Manipulator is considered as four mass systems for that are derived nonlinear
second order differential equations describing the acceleration, velocity and
movement of the input links and actuators.
3 ill. Bibl. 16. Engl.; sum. in Russian.
On generation of differential equation of additional contact-Broken
(C1C1B3) motion of passenger carriage’s
optimal brake leverage transmission. G. Sharashenidze, P. Kurtanidze, T.
Motsonelidze, G. Usanetashvili. “Problems of Mechanics”. Tbilisi,
2010, ¹ 2(43), pp. 14-21, (Engl.).
In
the works is solved problem of generation of additional contact-broken motion
differential equations of passenger carrisge’s optimal brake leverage
transmission due a real dynamic model of the transmission. Additional motion
equation are generated relating to generalized linear and angular coordinates
of transmission recorded in a form that combines kinematic and time variable
dynamic characteristics. At generating of differential equations are applied
coordinate transitional formulae, as well as functional relationships between
the forces of normal reactions and friction. The obtained differential
equations would be applied at development of comprehensive program of research
of optimal brake transmission on which basis would to determine the effect of
joint connections elements deterioration on the kinematic and dynamic
parameters of brake transmission. 1 ill. Bibl. 16. Engl.; sum. in Russian.
KINETIC
ENERGY OF 3 DOF PLANAR PARTLY DECOUPLED PARALLEL MANIPULATOR. Vo Dinh Tung. “Problems of Mechanics”. Tbilisi, 2010, ¹ 2(43), pp. 22-27,
(Engl.).
A
new planar parallel manipulator is considered. The translation movements are decoupled
from rotation. The kinetic energy of this parallel manipulator is determined by
using the equations expressing velocities. By this the rotational velocities of
the links and translation velocities of the centers of masses are expressed by
the generalized velocities. The links corresponding to planar motions are
expressed as three masses whose energy is equal to this of these links. 4 ill.
Bibl. 3. Engl.; sum. in Russian.
Structure of space reflactor Force Ring. Sh. Tserodze, E.
Medzmariashvili, M. Sanikidze, N. Tsignadze, M. Nikoladze, V. Gogilashvili, E. Logachevi. “Problems of Mechanics”. Tbilisi,
2011, ¹ 2(43), pp. 28-35, (Engl.).
Is represented the structural scheme of new transforming force ring, which represents consisting from rod elements
kinematical chain. Separate sections represent
the parallelogram mechanism on
which diagonals are installed translational motion two lever
group. Each section are
rectangular shaped and consists
from jointly connected rigid rods with telescope rod located
on a large diagonal. As a result would be technical and technological effects that in turn provide the
creation of deployable ring that even in the case of large dimensions represent rigid and light-weight
structure.
15 ill. Bibl. 9. Engl.; sum. in Russian.
OBTAINING
OF THE PERIODICAL PROFILES WITH THE EXACT PITCH BY MEANS OF THE COMBINED
PROCESSES OF ROLLING AND DRAWING. J.
Lomsadze, T. Natriashvili , Z. Lomsadze,
S. Mebonia . “Problems of
Mechanics”, Tbilisi, 2011, ¹ 2(43),
pp. 36-40, (Engl.).
In
article new scheme
of technological process for manufacturing of periodic profiles based on the combination of
rolling and drawing,
as well as the rtational construction installation for its realization
is proposed. The formula to determine the contact stress and deformation
of the metal
in the deformation zone is proposed. 4 ill. Bibl. 4. Engl.
sum. in Russian.
Engineering
theory of analysis of multilayer orthotropic axisymmetric shells of medium
thickness on complex elastic foundation.
J. Bichiashvili. “Problems of
Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 41-55, (Engl.).
Is
developed engineering theory of solutions of analysis tasks of axisymmetric
orthotropic multilayer medium thickness shells, located on complex Winkler type
elastic foundation that gives the possibility in combination with an iterative
technique to solve the problems of such type shells in linear as well as
in nonlinear formulation, without
application of nonlinear differential
equations of shell theory. Is defined the possibility of obtaining of analysis
results with a high degree of accuracy (from 0.01 and higher), are considered
some particular types of shells. 2 ill. Bibl.
14. Engl.; sum. in Russian.
THE
LOCOMOTIVE VIBRATORY PROCESSES AND THEIR INFLUENCE ON THE DRIVE TOOTH GEARING. V.
Zviadauri, G. Tumanishvili, M. Chelidze, G. Cockhalashvili. “Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp.
56-62, (Engl.).P
The
influence of dynamical loads generated as a result of the railway rolling stock
spatial vibrations on the drive transmission is considered in the paper. For
solution of the problem a generalized dynamical model of the rolling stock
spatial vibratory movement is considered, where the wheel-rail contact and
a motor of the drive are the source of
excitation, and as a closing link of the drive tooth of the power flows an
engagement of the drive tooth gering is considered. A central link is a pair of
the gear-wheels, from which a classical methods a system of interdependent
differential equations of the rolling stock and rail vibrations is obtained in
the work, that is important for study of simultaneous influence of various
parameters on the transmission vibratory movement and load. As a result of computer
modeling of the system of equations it will be possible to study an influence
of dynamical due to variation of the rolling stack various inertial and
geometric parameters on the movement of each gear-wheel and character of their
interaction. 2 ill. Bibl. 3. Engl.; sum. in Russian.
improvement
of freight transportation by perfection of rolling stock selection methods. O. Gelashvili, N. Butkhuzi. G. Tsertsvadze. “Problems of Mechanics”. Tbilisi,
2011, ¹ 2(43), pp. 63-66, (Engl.).
In the article is
considered issues of improvement of freight road transport efficiency due
perfection of rolling stock selection methods. By the motor transport is
carried out a variety of cargo transportation that raises the specific
requirements for rolling stock. Thus the rolling-stock selection that provides
reliable low cost freight traffic and safety, in specific operating conditions,
is rather actual. On the basis of analysis of the transport rolling stock
selection methodsis defined the great number of indicators, parameters and
variables on which basis the decision-making requires the development of
special multi-criteria method of evaluation In the work is mentioned taht all
models represents the classical transportation problem and its modifications
for that are nowadays is developed lot of solution methods and algorithms and
is necessary for each model to determine the optimal solution options. 2 ill. Bibl. 3. Engl.; sum. in Russian.
on assesment of Mechanical system’s
transient processes. M. Tsikarishvili, M. Mokhevishvili. “Problems of Mechanics”. Tbilisi,
2011, ¹ 2(43), pp. 67-71, (Engl.).
The paper is to present a
mathematical model intended for describing the transients that would originate
in some components of both mechanical structures and airspace-engineering
systems. Owing to the mathematical model made thereof, a new method of analysis
has been developed. It implies determination of the position and intensity of
the transients taking place in the components of a system. That is achieved
through applying the data obtained with the help of fiber-optic sensors. The
analysis cited here proves the adequacy of the mathematical model to the
findings of the experimental investigation where analytical preconditions were
obtained on the basis of Fourier's spectral analysis. Due to the qualities
fiber-optic sensors appear to exhibit, it becomes quite evident that the
technical state of the structures under investigation may be controlled
continuously throughout their life period. 3 ill. Bibl. 3. Engl.; sum. in Russian.
INTERACTION
OF THE TRACTOR DRIVING WHEELS WITH THE SOIL BY CONSIDERING THE RHEOLOGICAL
PROPERTIES OF SOILS. R. Makharoblidze,
I. Lagvilava, O. Asatiani, A. Kobakhidze. “Problems of Mechanics”. Tbilisi,
¹ 2(43), pp. 72-78, (Engl.).
The
work contains the results of theoretical studies of the process of interaction
of the tractor wheels with the soil. A rheological model is used as a law of
shear deformation of soils as the principal law of linear deformation.
Calculation formulae of tangential traction force and traction coefficient of
the tractor driving wheels are deduced. A numerical example and graphs are used
to demonstrate that the theoretical results are quite close to the experimental
data. The solution to the new questions of the indicators of the traction
dynamics, maneuverability and passability of the existing and newly designed
tractors and other wheeled power machines needs a further development of the
theory of interaction of the tractor driving wheels with the soil. 2 ill. Bibl. 9. Engl.; sum. in Russian.
FEATURES
OF ENTROPY CHANGEs AND VIOLATION of SECOND LAW IN LARGE SCALE SYSTEMS. A. Aptsiauri.
“Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 79-87, (Engl.).
In
the article on basis of energy and momentum conservation laws is indicated that
at the large scale heat-insulated stream, in the onset of turbulence process or
other relative motions, there is an apparent effect of cooling from without and
heat accumulation into kinetic energy, at simultaneously fall of entropy, which
contradicts with the requirement of second law.
4 ill. Bibl. 12. Engl.; sum. in Russian.
INVESTIGATION OF THE VARIABLE GEOMETRY ROTOR IN DINAMICS. Î.
Rukhadze, R. Turmanidze, R. Bidzinashvili, Å. Rukhadze. “Problems of Mechanics”. Tbilisi,
2011, ¹ 2(43), pp. 88-95, (Engl.).
In the article the
summary of state of the question of investigation of the rotors with variable
geometry parameters (
THE REFINED MODEL OF PLANE WAVES OF THE IDEAL FLUID IN A
BASIN. A. Tvalchrelidze. “Problems of Mechanics”. Tbilisi. 2011,
¹2(43), pp. 96-100, (Engl.).
There is considered in a given article the mathematical
model wave pattern on the sea coastal zone. On the basis of kinematic
hypothesis and d’Alembert-Lagrange principle there are derived the
one-dimensional equations and boundary conditions with simple mechanical sense.
The peculiarity of the model
consists in fact that with one-dimensional description of motion there are
simultaneously considered the extension of motion quantity and moment of fluid
mass motion quantity in transverse direction to coast. 1 ill. Bibl. 2. Engl.; sum. in Russian.
calculation
of multi-layered spatial systems with discontinuous parameters. Z. Sopromadze. “Problems of Mechanics” Tbilisi. 2011, ¹ 2(43), p. 101-104,
(Engl.).
Is stated the method of
calculation of multi-layered spatial systems with cuts. The method of cuts consideration
is grounded on application of special discontinuous functions that are
introducing in initial relations and decision equation as well as in desired
solution. The obtained solutions are reducing to easy algorithm and allows by
fast-realized programs to define the stress concentration. Bibl. 5. Engl.; sum. in Russian.
Improving
of prevention systems for providing vehicles technical state. V. Lekiashvili, M. Zurikashvili, D.
Ugulava. “Problems of
Mechanics”. Tbilisi, 2011,
¹ 2(43), pp. 105-107, (Engl.).
The
method of formation of classification groups for optimization of vehicle
maintenance modes is developed. For each group are presented models to
determine the optimal periodicity of performing preventive operations. As optimization
criterion is assumed level of probability of non-failure operation and minimum
of specific cost. 1 ill. Bibl. 7. Engl.; sum. in Russian.