#3(28), 2007



Numerical and experimental simulations of dynamic operators of cams. Giuseppe Carbone, Chiara Lanni, Marco Ceccarelli, Carlos Lopez-Cajun. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 7 – 20 , (Engl.).

In this paper we have proposed suitable dynamical models of cam systems that are based on use of lumped-parameters. Numerical simulations of a cam system have been elaborated by using the above-mentioned models. These models have been implemented in Matlab environment in order to define a mathematical model, which shows a good compromise between complexity and fitting with real system behavior. Experimental tests with several speeds of the input motion have been carried out by using a test-bed that has been designed and built specifically at LARM: Laboratory of Robotics and Mechatronics in Cassino. Satisfactory experimental results are shown to discuss also a validation of the proposed models. 8 ill. Bibl. 46. Engl.; summ. in Russ.


The analysis of the hinged mechanisms of warp-knitting machines. N. Davitashvili, L. Demetradze, L. Gergeshelidze. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 21 – 28, (Engl.).

In this paper, the analysis of the operating hinged mechanisms of warp-knitting machines carrying out diversified complex movements is given, which overlapping of separate operations for accomplishment of technological processes has rather important value. The formulas determining real angular and linear velocities and accelerations of output links and their points of the hinged mechanisms of warp-knitting machines with one, two and three degrees of freedom are received in general form. 2 ill. Bibl. 19. Engl.; summ. in Russ.


Preliminary thermal and catalytic fuel treatment in a
diesel engine injector. Oleh Klyus. “Problems of Mechanics”. Tbilisi, 2007,  ¹ 3(28), pp. 29 – 33, (Engl.).

This article presents the results of research on fuel injectors fitted with a system of fuel preheating directly in the injector nozzle holder. The application of catalytic coatings and elements in this system makes it possible to reduce fuel consumption and the emission of toxic compounds in exhaust gases. 5 ill. Bibl. 3. Engl.; summ. in Russ.


Research of some tribotechnical peculiarities of wheel/rail interaction. G. Tumanishvili, M. Chelidze. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 34 – 41, (Engl.).

The main problems of the wheel/rail fatigue are wear, plastic deformation and formation of flats of wheelflangs, wheelsets and gauges. In the paper is investigated the sliding distance and wheel rolling instance radius; the session influence on damageability of wheels and quantity of derailment of empty cars. Experimental researches are devoted to action of various parameters on a scuffing load, lubrication film thickness and friction factor of a rolling/sliding bodies. The comparison of sum aspects of lubricants and friction modifiers is given. 6 ill. Bibl. 11. Engl.; summ. in Rus.


Analysis of the purpose of efficient treatment of waste water and exhaust cases from sea ferries in shore and on board installations. Przemyslaw Rajewski. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 42 – 47, (Engl.).

The paper presents the results of a comparative analysis of efficient  waste water treatment from Polish  ferries by shore and shipboard waste water treatment installations.   The results of tests of shore as well as ships waste water treatment installations are included. New requirements of MARPOL, Annex VI and Directive 2005/33/EC imposing thereduction of SOx emission in ship exhausts gas entered into force in 2006. The emission of SOx can be reduced by the limitation of sulphur content in fuel or by means of exhaust gas desulphurisation methods. The author deals with available desulphurisation methods of exhaust gases as a result of high sulphur fuel burning. 4 ill. Bibl. 8. Engl.; summ. in Russ.


The dynamics of a translational pair with clearance of the operating transmission of diesel engine of refrigerator rolling stock. G. Sharashenidze, S. Sharashenidze, D. Kbilashvili, L. Machavariani. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 48 – 54, (Russ.).

The questions of theoretical investigations of the dynamics of translational kinematic pair of the operating slider-crank mechanism with clearances of the Diesel engine of rolling stock are presented. The parameters of free and contact motions of the translational pair with a clearance, maximum reaction forces with taking into account the coefficient of dry friction, frequency of the vibration of contact points and parameters of relative motion of the elements of the translational pair are determined. The results of investigation are given by analytical expressions, and also in the form of tables and diagrams. 3 ill. Bibl. 7. Russ.


Effectiveness conditions of heat regeneration during the use of thermodynamic cycle with the variable mass of working body. A. Aptsiauri. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 55 – 61, (Russ.).

It is offered the diagram of multiple regeneration of thermal energy by use of a cycle with the variable mass of working body. Five basic conditions, which, with appropriate assumptions, show the theoretical possibility of complete heat recovery, are formulated. Consequently, it is formulated the concept of multiple regeneration, which makes it possible to approach maximally to the theoretical limit of effectiveness for thermal installations. 6 ill. Bibl. 1. Russ.


Hydromechanical automatic stepless transmission of transport means. A. Nozadze. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 62 – 68, (Russ.).

Hydromechanical transmission transforming characteristic of an internal combustion engine`s torsion torque into stepless characteristic which is identical to carrier`s (motor vehicle, diesel locomotive, tank, etc) provides transmission of energy without power breach. It contains a torque converter, two planetary trains. The transmission is controlled by means of feedback from load moment and velocity of movement. The control unit, friction coupling, and band brake are not required. The last significantly simplifies construction and increases operation reliability. A method of calculation was elaborated; a pre-production model was produced and tested on brake stand. Design elaboration for concrete object is required. 5 ill. Bibl. 5. Russ.


Wavelet – the spectral analysis of transient processes. Tsikarishvili M., Bliadze S., Mokhevishvili M., Garibashvili I. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 69 – 75, (Russ.).

In this work, the possibilities of using the Wavelet-conversions and some of their properties are presented. The comparison between Wavelet and Fourier analyses is conducted and it is established a number of advantages of Wavelet-analysis in comparison with Fourier analysis. One specific example is also considered. 6 ill. Bibl. 4. Russ.


Traction resistance of the instrument while loosening deeply the tea-plantation's inter-rows. R. Makharoblidze, Z. Makharoblidze, B. Goshadze. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 76 – 79, (Engl.).

While loosening deeply the densed soil in the tea-plantation's inter-rows it is proposed the calculation formulas of efficiency and traction resistance of agricultural instrument. It is foreseen that the soil loosening is done streakily. In the upper layer up to critical height the loosening goes on with size of the soil shaving and in the layers the blocked cutting takes place. 1 ill. Bibl. 3. Russ.


Approximate solution of some functional equations. T. Vekua, G. Khvichia. “Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 80 – 84, (Russ.).

It is offered the methods of approximate finding of roots and estimation of their exactness for functional nonlinear equations. encountered when solving the boundary-value problems of dynamics, heat transfer of other problems of mechanics, machine building, and also in different areas of science and technology. Bibl. 3. Russ.


Numerical method of solution for some integral equations.
T. Vekua.
“Problems of Mechanics”. Tbilisi, 2007, ¹ 3(28), pp. 85 – 89, (Russ.).

In this work for the purpose of numerical solution of Volterra type first and second kind equations an unknown function is approximated by straight segment in each local interval. On a base of this approach it is obtained the recursion formula for computation of the intermediate values of desired solution, without the approximation of integral equation kernel. 2 ill. Bibl. 5. Russ.