SUMMARIES
¹1(42), 2011
Dynamical analysis of robot planar hingEd actuator
mechanism.
N. Davitashvili. “Problems of
Mechanics”. Tbilisi, 2011, ¹ 1(42), pp. 8-15, (Engl.).
Is
given the dynamical analysis of robot’s planar hinged actuator mechanism formed
on the basis of five-bar mechanism with two degrees of freedom and consisting
three grippers. Is given the operating principle and is shown the possibilities
of its operations in five modes. For one case of actuator mechanism’s and
grippers operation are obtained formulae of kinetic energy, reduced moments and
non-linear second order differential equations by solving of which are defined
real laws of motion of mechanism when
all links are absolutely rigid. 2 ill. Bibl. 7. Engl.; sum. in Russian.
Designing Fundamentals of Investigation
Equipment of Rotors with the Parameters of Variable Geometry. R. Turmanidze, Î.
Rukhadze, R. Bidzinashvili, Å. Rukhadze. “Problems of Mechanics”. Tbilisi,
2011, ¹ 1(42), pp. 16-23, (Engl.).
In this article the brief review of the state of question of designing
of the investigation equipment of rotors with the parameters of variable
geometry (the stand for dynamic tests of the VGR) is given. By calculation and
experimental ways the dependences of consumption power from values of
rotational speeds are determined. Also the hydro-system parameters of the stand
for dynamic tests of the VGR are determined. 4 ill. Bibl. 9. Engl.; sum. in
Russian.
comparative
analysis of dynamic loadings in joint connections with clearances of optimal
brake linkage transmission. G.
Sharashenidze, S. Sharashenidze, P. Kurtanidze.
“Problems of Mechanics”. Tbilisi, 2011, ¹ 1(42), pp. 24-32, (Engl.).
In this paper is carried out
comparative analysis of arising in passenger car’s optimal brake leverage
transmission’s joint connections with clearances friction and reaction forces.
A dynamic model of optimal brake leverage transmission with clearances is
applied for research. The additional contact motion of system is selected for
the carrying out of comparative analysis, when transmission rod endpoints
represent the internal elements of joint connections with clearances. Are
developed the equations of equilibrium and are obtained the functional
interdependence of dynamic loadings in the joint connections with clearances,
according of dynamic loadings distribution for contact points of rods and
vertical suspensions. In the expressions of comparative analysis are provided
the significant geometric values of clearances as well as the phenomena of dry,
wet and quadratic friction in the joint connections. For the arbitrary kind of
friction phenomenon would be selected the values of developed by brake cylinder
and brake shoe pressing force on the car’s wheel. The mathematical formulation
of the dynamic loading’s comparative analysis gives the possibility to apply
the principles of analysis in the sol of problems of kinematic and dynamic
synthesis of optimal brake leverage transmission. 1 ill. Bibl. 17. Engl.; sum. in Russian.
Structural
Models of Random Vibration’s Experimental Data. C. Mert, A. Milnikov. “Problems of Mechanics”, Tbilisi,
2011, ¹ 1(42), pp. 33-36, (Engl.).
A method of analysis of mechanical ossilations’
experimental data’s (experimental time series) internal structures based on
Singular Spectrum Analysis is discussed. It has been shown that in the case
when the Time Series contains deterministic additive components rank of the
trajectory matrices equal to number of parameters of the components. Also it
was proved that both eigen and factor vectors repeat shapes of the additive
components and both eigen values and eigen vectors can be divided into additive
groups. Some useful patterns of deterministic components were identified, which
permit to provide graphical analysis of
times series Internal Structures. Bibl. 12. Engl., sum. In Russian.
INTERACTION
OF THE UNDERCARRIAGE OF ADAPTIVE TANDEM-WHEELED SEIF-PROPELLED CHASSIS WITH THE
SOIL BASED ON THE RHEOLOGICAL MODELS.
R. Makharoblidze, I. Lagvilava, O.
Asatiani, A. Kobakhidze.”Problems of Mechanics”. Tbilisi, 2011, ¹ 1(42),
pp. 37-44, (Engl.).
The work contains the theory
of the interaction of the undercarriage of adaptive tandem-wheeled
self-propelled chassis with the soil. A rheological model of Voigt is used as
the deformation law of soils. A calculation formula for the soil deformation by
considering the relative location of the front steering and rear driving
tandems wheels is deduced. A numerical example is used to demonstrate the
reduction of the depth of trace after the passage of three tandem wheels of an
adaptive chassis as compared with that of a serial chassis. 1 ill. Bibl. 4.
Engl.; sum. in Russian.
RUNNING
WHEEL OF hoisting CRANE WITH
CHANGED shape OF ROLLING SURFACE.
M. Shilakadze, V. Kartvelishvili, M. Barbakadze, I. Jamburidze. “Problems of Mechanics”. Tbilisi, 2011, ¹
1(42), pp. 45-48, (Engl.).
In
the article is given the development of new designs of roll surface of gantry
cranes running wheels. The existing running wheels of hoisting cranes are
cylindrical in shape and lateral flange on two sides, which are extensively
worn. With the change of the hoisting crane’s wheels roll surface’s shape of
the and giving for it the possibility of axial movement is achieved the
minimizing of transverse forces that arises at crane moving due the deviations
of wheel, rail or railway geometrical parameters from the permissible values of
technical standards. As a result is reduced friction between the
rolling-sliding contact surfaces of wheel and rail, and consequently decrease
the additional vibrations of crane’s metalware, thus is achieving the
improvement of wear resistance and crane’s running wheel and total operating
life. 2 ill. Bibl. 8. Engl.; sum. in Russian.
ELECTRICAL
CONDUCTING AND PARAMAGNETIC PROPERTIES OF CHANNELS FORMED AFTER LASER BEAM
IRRADIATION OF SOME POLYMERS. J. Aneli, E. Semiletova, N. Bakradze, T. Dumbadze. “Problems of Mechanics”. Tbilisi,
2011, ¹ 1(42), pp. 49-53,
(Engl.).
Formation
of electrical conducting channels with paramagnetic properties on the surface
of three type polymer plates (phenol-formaldehide and epoxy resins,
polyacrylonitril) under influence of CO2 laser irradiation at the
presence of air have been studied. It is shown that the magnitude of surface
resistance of the investigated polymers depends on polymer type and irradiation
energy. The appearance of electrical conducting regions in the polymer
materials is due to laser-chemical transformations of macromolecular physical
and chemical structures near the polymer plate surfaces, leading to formation
of double conjugated bonds. These structures are characterized also with
paramagnetic properties- by method of ESR the free radicals are discovered in
the transformed regions of polymers. The obtained results practically are
analogous to ones obtained in such polymers after thermal treatment at high
temperatures. However here are some advantages. At last case for obtaining of
conducting materials on the base of dielectric polymers it is necessary the use
of high vacuum. Besides of such method don’t allows the formation of conducting
channels with desired square and configuration on the surface of polymer plates
in very short time (about several seconds) at present of air. 5 ill. Bibl. 6.
Engl.; sum. in Russian.
TO THE THEORY OF TEA LEAF TWISTING PROCESS: CRITERIA OF TWISTING AND AN EQUATION FOR THE DEGREE OF THE TEA MASS TWISTING. A. Tvalchrelidze, B. Kankadze. “Problems
of Mechanics”. Tbilisi. 2011, ¹ 1(42), pp. 54-60, (Engl).
For the closure of system of equations, modeling the
tea leaf twisting process, it is necessary to apply an additional equation
describing the time variation of the twisting degree at a material point of the
mass. This equation must contain the so-called twisting criterion. There are
proposed several admissible versions for this criterion. 5 ill. Bibl. 2. Engl.,
sum. in Russian.
Investigation of fuel
economy of gas turbine in hybrid cars. M. Ben Chaim, M. Brand, O. Gelashvili, N. Navadze. “Problems of Mechanics”. Tbilisi,
2011, ¹ 1(42), pp. 61-66, (Engl.).
Though since recently, hybrid cars are having
acceptable technical parameters. Until now, hybrid cars have been basically
using traditional internal combustion engines, either working on diesel or
gasoline, due to their state-of-the art nature and relatively high thermal
efficiency. However, when analyzing engine operation modes in hybrid cars, and
more particularly, their ability to operate in an optimal mode, a gas turbine
usually comes to mind, which is comparable to other thermal engines due to its
exceptional technical properties. Determining its performance in hybrid cars in
terms of fuel economy alone is technically incorrect, since all aspects of this
technical solution shall be taken into account. This paper is an attempt to
evaluate the performance of gas turbines as a main source of energy in hybrid
cars by means of system analysis.
1 ill. Bibl. 16. Engl.; sum. in Russian.
logistic
system of transport companies financial flows management. O. Gelashvili, G. Tsertsvadze, N. Butkhuzi. “Problems of Mechanics”. Tbilisi,
2011, ¹ 1(42), pp. 67-69, (Engl.).
In the work is considered the
logistic system of transport companies financial flow management, which is
based on the method of actual analysis and gives the possibility in arbitrary
reporting period to determine the financial condition of transport companies.
The developed logistic system provides transportation companies results
management by taking into account affecting financial flows current factors.
Also due the changes of these
factors values to fulfillment of transport companies financial forecasting. Bibl. 7. Engl.; sum.
in Russian.
Low
rank tensor approximation algorithm in Singular Value Decomposition Problem. C. Mert, A. Milnikov. “ Problems of
Mechanics ”, Tbilisi, 2011,
¹ 1(42), pp. 70-79, (Engl.).
A
new method of computation of singular values and left and right singular
vectors of arbitrary non-square matrices has been proposed. The method permits
to avoid solutions of high rank systems of linear equations of singular value
decomposition problem, which makes it not sensitive to ill-conditioness of
decomposed matrix. On base of Eckart-Young theorem, it was shown that each
second order r-rank tensor can be represent as a sum of the first rank r-order
“coordinate” tensors. A new system of equations for “coordinate” tensor’s
generators vectors was obtained. An iterative method of solution of the system
was elaborated. Results of the method were compared with classical methods of
solutions of singular value decomposition problem. Bibl. 9. Engl., sum. In
Russian.
About
development of special technical schedule providing in post-soviet countries
railway transport and its infrastructure’s safety.
M. Moistrapishvili, E. Moistrapishvili,
N. Rurua. “Problems of Mechanics”. Tbilisi, 2011, ¹ 1(42), pp. 80-86, (Engl.).
After
the separation of former Soviet Union’s unified railway network, CIS and Baltic
countries have become an urgent necessity to develop a special regulation on
the technical safety of railway transport and its infrastructure.
In
this document by chapters and paragraphs are presented the all conceivable main problems, are
given the clarifications and clarification of basic terms that are required for
the development of technical rules of national special safely railway transport
and its infrastructure, with taking into consideration and concordance with
international approach. This approach gives the possibility to provide a high
degree of safety and to minimize the concomitant risks.
Regulations
of ensuring the safety railway transport and its infrastructure must meet the
following requirements:
Thus
the task of development of special technical regulations of railway transport
and its infrastructure safety must be mandatory for the post-Soviet countries
for integration of their transport systems in the world transport system is
urgent and mandatory. 2
ill., Bibl. 3 Engl.; sum. in Russian.
definition
of directions of georian railway passage technical capacity development in
relation of cargo TRAFFIC CHARACTER.
P. Kenkadze, A. Sharvashidze, G. Guramishvili, G. Lomouri, K.
Sharvashidze. “Problems of
Mechanics”. Tbilisi, 2011, ¹ 1 (42), pp. 87-90, (Engl.).
in the
conditions of transport market repartition and functioning of new freight
directions in the paper is considered freight character of Georgian railway
passage and prediction of perspective cargo traffic, possibility of direction
of technical development definition. 1 ill.
Bibl. 3. Engl.; sum. in Russian.