#4(37), 2009



NEWSLETTER OF IFToMM. “Problems of Mechanics”. Tbilisi. 2009, ¹ 4(37), pp. 5-9 .



kinematic analysis and precision of sewing-machine thread takeup linkage mechanism. N. Davitashvili, Kh. Khabuliani. “Problems of Mechanics”. Tbilisi, 2009, ¹ 4(37), pp. 10-16, (Engl.).

The solutions of kinematic research and kinematic precision problems of the light industry sewing-machine thread takeup linkage mechanism (together with carrying needle) are given. The kinematic parameters of output links and their points are defined. With the account of primary (technological) errors are found the positioning errors of output links and their points, as well as for whole mechanism. By computer machinery is solved the numerical example which results is given by diagrams. 3 ill. Bibl. 10. Engl.; sum. in Russ.



DISTRIBUTING OF PRESSURES ALONG PRESS CHAMBER OF SCREW WORKING ORGAN. R. Makharoblidze, O. Tedoradze, M. Gachechiladze.  Problems of Mechanics”. Tbilisi, 2009, ¹ 4(37), pp. 17-23, (Engl.).

Is stated the theory of screw working organ compression chamber design of distributing of pressure and force of friction along the chamber. Calculation formulas are shown out for determination of pressure on the bottom of chamber mobile part and force of friction of material at the walls of immobile and mobile chambers. It is set that force of friction depends on attitude of perimeter of chamber cross-sectional toward his area.  Most rational is the round section of chamber. From point of energy consumption on overcoming of friction the chambers of large section are more expedient. 3 ill. Bibl.3 Engl.; summ. in Russ.



MODELING of chain structures mechanisms motion with elasto-friction links. N. Baidarashvili, I. Zedelashvili, V. Gogilashvili.  Problems of Mechanics”. Tbilisi, 2009, ¹ 4(37), pp. 24-31, (Engl.).

The long-length chain system with elastic-frictional links is considered. The dynamic analysis of system is carried out on the presented basic contour on the basis of the nonlinear differential equation. Spectra of frequencies, dynamic transfer functions are defined at variation of geometrical parameters for the considered long-length system. 3 ill. Bibl. 4. Engl.; sum. in Russ.



ELABORATION OF THE MODEL OF LOGISTICAL SYSTEM “ECOLOGICAL SAFETY OF AUTOMOBILES — DIESEL OIL PROPERTIES”. T. Natriashvili, D.Iosebidze, O. Gelashvili, G. Abramishvili. “Problems of Mechanics”. Tbilisi, 2009, ¹ 4(37), pp. 32-42, (Engl.).

On the basis of results of existent researches conceptual relations between quantity of harmful exhausted products of automobile diesel engines and indices of diesel oil such as : fractional composition, cetane number, viscosity, density, ashiness, cokiness, acidity, contents of sulphur and actual pitches, etc, are established. Significant influence of the oil basic indices (temperatures corresponding to distillation of 50%, 90% and 96%, cetane number, etc.) on the mentioned automobile ecological indices is confirmed. A model of logistical system of the relation between automobile ecological safety indices and diesel oil properties is elaborated taking into account the revealed conformities with a law. Regulation of magnitudes of the model components ensures retaining of the planned level of automobile ecology and enables also to reveal perspective ways and modes for its rise. 7 ill. Bibl. 4. Engl.; sum. in Russ.



EQUILIBRIUM EQUATIONS OF THE FINITE ELEMENT IN THE THEORY OF SHELLS WITH THE USE OF SEVERAL BASIC SURFACES.  A. Tvalchrelidze, K. Tskhakaia. Problems of Mechanics”. Tbilisi, 2009, ¹ 4(37), pp. 43-47, (Engl.).

Finite element method gives the effective method of algorithms construction for boundary-value problem of the theory of shells with the use of several basic surfaces. There are derived in a given article the equilibrium equations of the finite element within the framework of theory in general and linear versions. These equations are the basic equations in the finite-element settings with numerical solution of different applied problems of the calculation of shell constructions. Bibl. 2. Engl.; sum. in Russ.



ABOUT AN OPPORTUNITY OF OVERCOMING OF A LIMIT OF THERMAL MACHINES EFFICIENCY AND THE SECOND  LAW. A. Aptsiauri. “Problems of Mechanics”. Tbilisi. 2009, ¹ 4(37), pp. 48-52, (Engl.).

In work, on the basis of theoretical research  is shown that, in local area of any system  the process can occur with reduction of entropy and increase of order only because of action of accidental, locally natural and external forces  and also in that cases when in such system  purposeful action of the intellectual subject takes place, thus the charge of physical energy is obligatory only in that case if  in this process  is necessary to overcome the resistance of  physical bodies. Hence, as the basic obstacle, for achievement of maximal efficiency, not temperature limits but physical properties of bodies are considered. Bibl. 6. Engl.; sum. in Russ.



Application of vibration in the wall plastering-covering and cleaning works. M. Chelidze, V. Zviadauri, G. Tumanishvili,  A. Gogava. Problems of Mechanics”. Tbilisi, 2009, ¹ 4(37), pp. 53-57, (Engl.).

 Presented possibility of realization of the fixing of the fluid plastic material and its compactions on vertical plane be means of vibration. Vibro-processing reduces to minimum air bubbles in the inficted layer and compacts it. Because of reduction air bubbles occurs: reduction off the volume freezing water in concrete covering layer, destruction covering layer wall and increased contact covering layer surfaces with the wall. 5 ill. Bibl. 8. Engl.; sum. in Russ.



T. Buchukuri, G. Tumanishvili. Problems of Mechanics”. Tbilisi, 2009, ¹ 4(37), pp. 58-62, (Engl.).

The discrete parts of contact zone at friction are regarded as the primary heat sources. The process heat distribution in micro asperities mathematically modeled by the three-dimensional boundary value problem. Solution of the problem is obtained in expanded form. Calculations based on the obtained solutions allow to compute the temperature field in micro asperity and receive more detailed picture of heat absorption by bodies and surroundings and estimate thermal loading of contact with regard to environmental characteristics. 1 ill. Bibl. 7. Engl.; sum. in Russ.



mathematical model of technological parameters definition for footwear test device. T. Maglakelidze, M. Zakaraia. Problems of Mechanics”. Tbilisi, 2009, ¹ 4(37), pp. 63-68, (Engl.).

In work are presented the result of short review of contact problems. It is received at research interaction of isotropic, anisotropic and non-uniform materials. The principal attention was given to those mainstreams, which were allocated at research of contact problems for above specified materials and structural components. 4 ill. Bibl. 2. Engl.; sum. in Russ.