¹ 1(38), 2010
SUMMARIES
NEWSLETTER OF
IFToMM. “Problems of Mechanics”.
Synthesis of sewing-machine thread takeup joint mechanism according given output links law of motion.
N. Davitashvili, Kh. Khabuliani. “Problems of Mechanics”.
Is stated
solution of problems of synthesis of sewing-machine thread takeup joint
mechanisms (together with carrying needle) according the given of output links
law of motion. The problem is solved by two – grapho-analytical and analytical
methods. In the first case, according the given output links law of motion
(needle) are defined the sizes of links, and in the second case, according the
given thread takeup and needle law of motion are analytically defined all
parameters of the mechanism. The received expressions and the equations are
realized by computer machinery. 3 ill. Bibl. 13. Engl.; sum. in Russian.
SOLUTIONS OF SOME PROBLEMS
OF IMPROVEMENT OF ECOLOGI-CAL CHARACTERISTICS OF THE DIESEL ENGINE CONVERTED IN
THE GAS ENGINE. T.
Natriashvili, M. Glonti, R. Kavtaradze, Z. Kavtaradze, A. Zelentsov.
“Problems of Mechanics”.
Questions of influence of
a combustion chamber shape, swirl
intensity, the location of a of a spark plug and spark angle on ecological
parameters of a piston engine are little-investigated till now. Necessity of
the solution of these problems arises at converting of the serial diesel engine
in the gas engine with a spark ignition of an air-gas mixture, when natural gas
is used as a motor fuel. The mathematical model consists of three-dimensional
non-stationary transport equations, and also turbulence and combustion models.
Numerical experiments have been carried out with application of program code
FIRE. Best values of parameters of the working process, ensuring improving of
effective and ecological parameters of the diesel engine converted in the gas
engine are defined. 12 ill. Bibl.
17. Engl.; sum. in Russian.
About DYNAMIC ANALYSIS of existing and OPTIMAL BRAKE leverage SYSTEMS. G. Sharashenidze, P. Kurtanidze, T. Dundua,
The
development brake linkage mechanical system with minimal losses of brake force
characterized by simple structure and reliability operation is very topical and
problematic task. Nowadays the brakes systems consist from number of levers
therefore are characterized by force great losses in the hinge junctions on the
friction overcoming, great material capacity and making costs. For brake
mechanical systems optimal design due developed in the dynamic model are solved
the dynamic analysis tasks. Due the carried out theoretical researches and
according computational experiment is achieved the topical task solution.
Carried out in the work research is acceptable for other kinds of brake
mechanical systems optimization task solution as well as is possible fore
application at development and research of arbitrary complexity lever
mechanical system. 7 ill. Bibl. 13. Engl.; sum. in Russian.
CIRCULAR FLOW AND QUESTION OF OVERCOMING OF THERMAL INSTALLATIONS MAXIMAL
EFFICIENCY. A. Aptsiauri. “Problems
of Mechanics”.
In articlet is shown, that at use of materials with high heat
conductivity, Kueet flow of gas can be applied to realization of process
of the thermal pump or the thermal engine which efficiency is higher, than
efficiency of Carnot cycle in same
interval of limiting temperatures. Thus it is proved, that the marginal
efficiency of thermal installations depends on property of substances instead
of from a level of temperature balance of bodies in space environmental us.
Hence, the basic obstacle for realization of a perpetuum mobile of the second
kind is viscous and thermal resistance
of real ph. 3 ill. Bibl. 5. Engl., sum. in Russian.
TO QUESTION of dynamic processes analysis and
synthesis in drives complex mechanical systems. T.
Mchedlishvili, Z. Balamtsarashvili, E. Kristasiashvili, G. Tratiashvili, T.
Anjaparidze. “Problems of
Mechanics”.
The drives of modern
machines generally represent rather complex dynamic systems including
mechanical transmission (mechanical system MS) which, in turn, can have rather
complex manifold or ring structure. Complexity of considered
systems dynamic researches in many respects is defined by the choice of MS
design model. This scheme, in turn, regulates the qualitative and
quantitative parties of defined free components of transient processes.
Actual are the problems connected with construction of mathematical models,
considering only essential degrees of freedom, and formation of basic laws for
realization of mathematical procedures of the subsequent purposeful dynamic
researches. Thereupon in the present work are considered questions of
approximate models development of structurally complex of multimass drive
systems. As a result of the carried out researches are offered the original
methods of transition to simplified approximate models and realization of the
mathematical procedures directed on dynamic synthesis of investigated systems.
Bibl. 8. Engl.;
sum. in Russian.
Ways increas static, dynamic and aerodynamic stability
of wind power to wers for
In March, 1999 by Japan Consulting Institute is
presented the research report on the wind power generation project in
Analysis of lateral vibration behavior of
wheelset in straight track. G.
Tumanishvili, V. Zviadauri, M. Chelidze, M. Tsotskhalashvili. “Problems of
Mechanics”.
Abstract: The features of movement of the
carriage wheelset (without a bogie); a wheelset with the bogie but without a
carriage; and a wheelset with the bogie and carriage, are considered in the
paper. Conformities with a low of the period of zigzag motion, intensity of the
lateral displacement, angle of attack and sliding for the free wheelset and
also conditions of a generation of the creep, sliding and resonant vibrations
for each circumstance, are revealed. 4 ill. Bibl. 4. Engl.; sum. in Russian.
solution of problem about mode of deformation of inclined shells with
DISCONTINUOUS PARAMETERS. N.
Todua. “Problems of Mechanics”.
are considered the general
methods of generation of differential equation and, methods of simplification
for special cases. Is concretized the method of the solution of differential
equations with variable and pulse coefficients concerning of problems of
calculation of inclined shells with discontinuous parameters in the conditions
of nonlinear deformation. 1ill. Bibl. 4. Engl., sum. in Russian.
Influence of freight car truck (model 18-100)
on deterioration "wheel-rail” SYSTEM in small radius curves of way and
necessity of their bearer’s modernization. A.
Sharvashidze, D. Gogishvili, K. Sharvashidze. “Problems of Mechanics”.
Is considered one of the major problems of
railway transportation, which concerns of the track and car interaction on
sites of small radius of way at which occurs the lateral deterioration of wheel
flanges and rail heads which source is the 18-100 freight cars truck. The
accent becomes on necessary of out-of-date imperfect box-shaped bearer’s
replacement, which are located on the truck bolster and are one of the reasons
of above-mentioned deteriorations. We recommend to apply as bearer’s the
spherical design bearers, in particular in pairs from each side of truck
bolster in special boxes are longitudinally located balls which at contact with
bearers car body make only rolling friction (instead of kinetic and rolling
friction which occur in cylindrical rollers). Also is considered the question
of this structure with elastomer. The structure is developed and also is
improved its dynamic model and mathematical apparatus. 2
ill. Bibl. 6. Engl.; sum. in Russian.
Working out and
investigation of energy-economical efficiency of energy-preserving heat-cold
supplying systems on basis of heat pump plant and geothermal water on agroindustrial complex enterprises. K.
Vezirishvili-Nozadze, N. Mirianashvili,
T. Gedevanishvili. “Problems
of Mechanics”.
The results of technical and economic investigations of the complex
heat-cold provision systems working on the basis of the heat pumping plants for
the milk processing plants are given in the paper. 5 ill. Bibl.
3. Engl.; sum. in Russian.
Effect of modify by tetraethoxysilane of the mineral fillers on some
properties of composites based on epoxy resin. J. Aneli, O.
Mukhbaniani, E. Markarashvili, L. Shamanauri. “Problems of
Mechanics”.
¹ 1(38), pp. 82-87, (Engl.).
Ultimate
strength, softening temperature, and water absorption of the polymer composites
based on epoxy resin (type ED-20) with unmodified and/or modified by
tetraethoxysilane (TEOS) mineral diatomite are described. Comparison of
experimental results obtained for investigated composites shows that ones
containing modified filler have the better technical parameters mentioned above
than composites with unmodified filler at corresponding loading. Experimentally
is shown that the composites containing binary fillers diatomite and andesite
at definite ratio of them possess the optimal characteristics – so called
synergistic effect. Experimental results are explained in terms of structural
peculiarities of polymer composites. 8 ill. Bibl. 8. Engl.; sum. in Russian.