¹2(51), 2013

SUMMARIES

 

MODELING OF RADIATIVE-CONVECTIVE HEAT TRANSFER IN THE DIESEL ENGINE. T. Natriashvili, R. Kavtaradze, Z. Kavtaradze,  A. Zelentsov,  D. Onishchenko.  “Problems of Mechanics”. Tbilisi, 2013, ¹ 2(51), pp. 6-12 (Engl.).

  The turbulent boundary layer is investigated on the combustor surface of arbitrary curvature subjected to the flow of a working medium which radiates and absorbs thermal energy. New integral relations of boundary layer are used for solving equations of complex heat transfer. The authors investigated the turbulent Prandtl number in the case of combined radioactive and convective heat transfer. The calculated values of local heat flux on the combustor surface are in good agreement with the experimental data obtained in a high-speed diesel engine under conditions of bench tests. 3 ill. Bibl. 12. Engl.; sum. In Russian.

 

 

FUNCTIONAL PROPERTIES OF STEPLESS GEAR ADAPTIVE TRANSMISSIONS.
K. Ivanov, S. Joldasbekov, A. Jomartov, Y. Temirbekov. “Problems of Mechanics”. Tbilisi, 2013, ¹ 2(51 ), pp. 13-20 (Engl.).

The gear adaptive progressive transmission can be created in the form of the kinematic chain with two degrees of freedom having the mobile closed contour with toothed wheels. The closed contour imposes a constraint on motion of links and transforms the kinematic chain into the mechanism with one input. Such mechanism gets property of automatic adaptation to variable technological loading. Regularity of interconnection of power and kinematic parameters is resulted. The animation model and a design of gear adaptive transfer are presented. 4 ill. Bibl. 7. Engl.; sum. in Russian. 

 

FUNCTIONAL PROPERTIES OF STEPLESS GEAR ADAPTIVE TRANSMISSIONS.
Y. Temirbekov, S. Joldasbekov, A. Jomartov. “Problems of Mechanics”. Tbilisi, 2013, ¹ 2(51), pp. 21-27 (Engl.).

The gear adaptive progressive transmission can be created in the form of the kinematic chain with two degrees of freedom having the mobile closed contour with toothed wheels. The closed contour imposes a constraint on motion of links and transforms the kinematic chain into the mechanism with one input. Such mechanism gets property of automatic adaptation to variable technological loading. Regularity of interconnection of power and kinematic parameters is resulted. The animation model and a design of gear adaptive transfer are presented. 3 ill. Bibl. 3. Engl.; sum. in Russian. 

 

FUNCTION GENERATION SYNTHESIS OF PLANAR 5R MECHANISM. Gokhan Kiper, Tunc Bilgincan, Mehmet Ismet Can Dede. “Problems of Mechanics”. Tbilisi, 2013, ¹ 2(51), pp. 28-31 (Engl.).

This paper deals with the function generation problem for a planar five-bar mechanism. The inputs to the mechanism are selected as one of the fixed joints and the mid-joint, whereas the remaining fixed joint represents the output. Synthesis problem of the five-bar mechanism is analytically formulated and an objective function is expressed in polynomial form. Function generation synthesis is performed with equal spacing and Chebyshev approximation method. The four unknown construction parameters and the error are evaluated by means of five design points and the coefficients of the objective function are determined by numerical iteration using four stationary and one moving design point. Stationary points are placed at the boundaries of the motion and the moving point is re-selected at each iteration as the point corresponding to the extremum error. Iterations are repeated until the values are stabilized. The stabilization usually occurs at the third iteration. By this method, the maximum error values are approximately equated, hence the total error is bounded at certain limits. Finally the construction parameters of the mechanism are determined. 6 ill. Bibl. 5, Engl., sum. in Russian.

 

ACQUIRED VARIABLE DESAXIAL IN MECHANICAL SYSTEMS WITH COUPLER-PISTON GROUPS AND INCREASED CLEARANCES. G. Sharashenidze, T. Dundua,
G. Usanetashvili.  “Problems of Mechanics”. Tbilisi, 2013, ¹ 2(51), pp. 32-41, (Engl.).

A phenomenon of a variable desaxial in plane mechanisms with connecting rod-piston groups and clearances in hinged junctions is studied in the work. Conditions of generation and variation of an acquired variable desaxial in the course of the mechanism operation at instantaneous displacement of the piston along the line of instantaneous action are elaborated. A value of the variable desaxial and limits of its expansion are established. Corresponding analytical expressions considering clearances and variable generalized coordinates are obtained. Accomplished analysis of the variable desaxial can be used in the course of research of mechanisms of any complexity having connecting rod-piston groups and clearances. 4 ill. Bibl. 13. Engl.; sum. in Russian.

 

 THE ANALYSIS OF AN AFTER-EFFECT OF  IMPACT IN TRANSMISSION  AT  SLEEVE  CAPTURE  BY  ROLLS  OF THE  AUTOMATIC  MILL. S. Mebonia, D. Demetradze,  P. Mshvildadze, A. Gagnidze.   “Problems of Mechanics”. Tbilisi, 2013, ¹ 2(51), pp. 42-46 (Engl.).

In article the problem of transformation of the impact impulse arising in the automatic mill deformation centre in the mill transmission is considered at secondary capture of metal by rolls. The formulae for calculation of the angle of twisting of the intermediate shaft of the automatic mill transmission and the coefficient of dynamism are obtained. 4 ill. Bibl. 6. Engl.; sum. In Russian.

 

GENERATION of usable ENERGY BY alternation OF INTERNAL ACCUMULATION AND ENERGY RELEASE PROCESSES AND WATER AS STRANGE Fuel. A. Aptsiauri. “Problems of Mechanics”. Tbilisi, 2013, ¹ 2(51), pp. 47-56, (Engl.).

In the article is shown that if in the thermodynamic cycle, at a specific temperature, I carried out the heat-insulated process with heat absorption, and the reverse process with heat release occurs at a higher temperature, the thermodynamic cycle would continuously generate usable energy from the heat. As an example is stated the water decay and reverse synthesis cycle and was shown that the water thus becomes in a source of heat and mechanical energy, although, in reality, at this is consumed the environmental heat or another kind of energy (in particular, vacuum energy). 4 ill. Bibl. 7. Engl.; sum. in Russian.

 

LOW CYCLE FATIGUE OF DEFORMABLE AUSTEMPERED DUCTILE IRON (DADI).
N. Khidasheli, G. Beradze, E. Kutelia, G. Khvichia.  “Problems of Mechanics”. Tbilisi, 2013,
¹ 2(51), pp. 57-63, (Engl.).

Complex investigation on the effect of combination of high-temperature thermo -mechanical (HTTM) treatment ( hot rolling, pressing, extrusion and forging) and multistep austempering processes on the low cycle fatigue (LCF) behavior of deformable austempered ductile iron (DADI) was carried out by the methods of LCF testing, SEM, TEM and X-ray diffraction analyses.           For experiments there were cast two compositions of DADI: first – high-silicon (2.2 % Si), low-alloyed by molybdenum and cooper; second – with low-silicon (0.5 - 1% Si) containing aluminum (1.5 - 2% Al) .The optimum combination of high strength and good LCF properties of DADI is caused by the ultrafine dispersion of the microstructure and the variable content of retained austenite.  5 ill. Bibl. 9. Engl.; sum. in Russian.

 

A ROD MODEL OF ELECTRIC MACHINES: ELECTRIC INTERACTION OF RODS WITH ACCOUNT FOR “DELAYED” DISTANCE. A. Tvalchrelidze, K. Tskhakaia, “Problems of Mechanics”. Tbilisi. 2013, ¹ 2(51), pp. 64-68 (Engl.).

For describing the electromechanical energy conversion in the electrical machines there is proposed in a given article to examine the interactions of electricity-conductive rods located along and transverse to the axis of the machine. Within the framework of a rod model there were considered previously the magnetization phenomena of cores. The given paper dwells on the basic relations of electric interactions of rods with account for “delayed” distance. 3 ill. Bibl. 4. Engl.; sum. in Russian.

 

analysis of damping coefficients of three-layered symmetrical structure plates. J. Kakhidze, M. Vazagashvili. “Problems of Mechanics”. Tbilisi, 2013, ¹ 2 (51), pp. 69-72, (Engl.).

In the article is carried out the multi-parametrical analysis of influence of geometrical parameters and rheological properties of materials of structure’s components on damping coefficients. The revealed earlier for simple mechanical systems synergy effect of dissipative properties for structurally non-uniform prismatic structures is proved. 5 ill. Bibl. 5. Engl.; sum. in Russian.

 

providing of train traffic safety on having mountaneous conditions railway by running order of rolling stock brake system.
A. Sharvashidze, A. Kakabadze, B. Didebashvili. “Problems of Mechanics”. Tbilisi, 2013, ¹ 2(51), pp. 73-76, (Engl.).

In the article are considered issues of freight trains traffic safety in mountainous conditions of railways, quite a number of stages are characterized by small radius curves and large slope. At their passing heavy-tonnage freight trains require special traffic safety measures as well as the providing by brake devices. Due researches is defined the necessity of providing freight train safety by electric regenerative brake. 1 ill. Bibl. 5. Engl.; sum. in Russian.

 

ROAD TRAFFIC ACCIDENT RATE IN ARMENIA AND IN SOME COUNTrIES around the WORLD. Y. Vardanyan, C. Burnusuzyan, V. Harutyunyan. “Problems of Mechanics”. Tbilisi, 2013, ¹ 2(51), pp. 77-82 (Engl.).

In this paper is carried out an analysis of road traffic accidents statistical data, collisions and fatalities occurred in the period from 2000 to 2010 in Armenia and some foreign states. This analysis shows that in high-income countries the number of fatalities due to road accidents is decreasing up to 50%, meantime in Armenia it has increased by 34%. Totally in low-income and middle-income countries more people are died due to road traffic accidents than in high-level countries.

In addition to accident rate absolute indices have also been analyzed relative indices (fatalities per 100,000 inhabitants, the number of vehicles per 1000 inhabitants, fatalities per 100 road traffic accidents), as well as predicted grow of fatalities on road accidents. Bibl. 6. Engl.; sum. in Russian. 

 

COMPOSITES BASED ON EPOXY RESIN AND GROUND FROM THE PLANET MARS. J. Aneli, O. Mukbaniani, L. Shamanauri. “Problems of Mechanics”. Tbilisi, 2013, ¹ 2 (51), pp. 83-89, (Engl).

Strengthening, softening temperature, and water absorption of the polymer composites based on dian epoxy resin (type ED-20) and unmodified and modified by tetraethoxysilane the ground from the planet Mars are studied. Comparison of experimental results obtained for investigated com­posites shows that ones containing modified filler have more high values of mentioned above parameters than composites with unmodified one at definite loading. The obtained results are described in terms of structural peculiarities of composite materials. 6 ill. Bibl. 6. Engl.; sum. in Russian.

 

research of transport process parameters in orfer of increasing of container traffic effectiveness. N. Butkhuzi.  “Problems of Mechanics”. Tbilisi, 2013, ¹ 2 (51), pp. 90-93, (Engl).

In this paper is considered the methods to improve the efficiency of container transport and are investigated the transport process parameters. During the analysis of container flow values was found that there is a tendency to increase the volume of container traffic. The process of containerization has initiated the development of transportation systems by using of terminals. The application of terminal technology, combined with the principles of logistics gives the possibility to increase the efficiency of transport operations, to provide high quality of service and reduce the time of cargo delivery. With consideration of the application of logistics principles are determined the optimal number of technical and technological parameters characterizing the operational and financial reliability of container traffic. 2 ill. Bibl. 7. Engl.; sum. in Russian.

 

some plasto-elastic problems. A. Buksianidze. “Problems of Mechanics”. Tbilisi, 2013, ¹ 2 (51), pp. 94-98, (Engl.).

In the article fully is studies case of constant thickness layer. In this case according integro-simultaneous equation of Prandtl by expansion method of Chebishev polynomials would be reduced to infinite system of algebraic equations that would be solved on computer by truncation method. Bibl. 5. Engl.; sum. in Russian.