¹ 1(38), 2010



NEWSLETTER OF IFToMM. “Problems of Mechanics”. Tbilisi. 2010, ¹ 1(38), pp. 5-6.


Synthesis of sewing-machine thread takeup joint mechanism according given output links law of motion. N. Davitashvili, Kh. Khabuliani.  “Problems of Mechanics”. Tbilisi, 2010, ¹ 1(38), pp. 7-12, (Engl.).

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”. Tbilisi, 2010, ¹ 1(38), pp. 13-28, (Engl.).

            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, S. Sharashenidze, L. Balon.  “Problems of Mechanics”. Tbilisi, 2010, ¹ 1(38), pp. 29-38, (Engl.).

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”. Tbilisi, 2010, ¹ 1(38), pp. 39-48, (Engl.).

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”. Tbilisi, 2010, ¹ 1(38), pp. 49-52, (Engl.).

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 Georgia. Yu. Melashvili, M. Tsikarishvili, L. Zambakhidze, V. Balavadze, G. Bokhashvili, M. Kiknadze. “Problems of Mechanics”. Tbilisi, 2010, ¹ 1(38), pp. 53-59, (Engl.).

In March, 1999 by Japan Consulting Institute is presented the research report on the wind power generation project in Georgia. In this project supporting the nacelle tower is monopole type approximately 40 meter height, which is supported by reinforced concrete foundation. The top diameter of tower is 2.0 m and base diameter 3.2 m. The tower is designed to undergoes the 59.5 m/sec wind speed (instantaneous) at hub height. In this report isn’t specified the tower and blades stability at wind critical speed. This is very important for safety of WPS towers, especially for Georgian highlands. This report is dedicated for WPS towers stability factor for Georgian highlands. 1 ill. Bibl. 4. Engl.; sum. in Russian



Analysis of lateral vibration behavior of wheelset in straight track. G. Tumanishvili, V. Zviadauri, M. Chelidze, M. Tsotskhalashvili. “Problems of Mechanics”. Tbilisi, 2010, ¹ 1(38), pp. 60-64, (Engl.).

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”. Tbilisi, 2010, ¹ 1(38), pp. 65-70, (Engl.).

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”. Tbilisi, 2010, ¹ 1(38), pp. 71-75, (Engl.).

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”. Tbilisi, 2010, ¹ 1(38), pp. 76-81, (Engl.).

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”. Tbilisi, 2010,
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.