¹2(43), 2011



dynamical research of planar closed chain manipulators with elastic links. N. Davitashvili.  Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 5-13, (Engl.).

Is given the dynamic investigation of planar manipulator with two degrees of freedom, taking into account the elasticity of links, kinematic chain of that is closed. At the first stage of the study is given the description of links elastic deformation determining method. Further are defined: reduced coefficient of stiffness of manipulator, and kinetic and potential energies. Manipulator is considered as four mass systems for that are derived nonlinear second order differential equations describing the acceleration, velocity and movement of the input links and actuators.  3 ill. Bibl. 16. Engl.; sum. in Russian.


On generation of differential equation of additional contact-Broken (C1C1B3) motion of passenger carriage’s optimal brake leverage transmission. G. Sharashenidze, P. Kurtanidze, T. Motsonelidze, G. Usanetashvili.  Problems of Mechanics”. Tbilisi, 2010, ¹ 2(43), pp. 14-21, (Engl.).

In the works is solved problem of generation of additional contact-broken motion differential equations of passenger carrisge’s optimal brake leverage transmission due a real dynamic model of the transmission. Additional motion equation are generated relating to generalized linear and angular coordinates of transmission recorded in a form that combines kinematic and time variable dynamic characteristics. At generating of differential equations are applied coordinate transitional formulae, as well as functional relationships between the forces of normal reactions and friction. The obtained differential equations would be applied at development of comprehensive program of research of optimal brake transmission on which basis would to determine the effect of joint connections elements deterioration on the kinematic and dynamic parameters of brake transmission.  1 ill. Bibl. 16. Engl.; sum. in Russian.


KINETIC ENERGY OF 3 DOF PLANAR PARTLY DECOUPLED PARALLEL MANIPULATOR. Vo Dinh Tung. Problems of Mechanics”. Tbilisi, 2010, ¹ 2(43), pp. 22-27, (Engl.).

A new planar parallel manipulator is considered. The translation movements are decoupled from rotation. The kinetic energy of this parallel manipulator is determined by using the equations expressing velocities. By this the rotational velocities of the links and translation velocities of the centers of masses are expressed by the generalized velocities. The links corresponding to planar motions are expressed as three masses whose energy is equal to this of these links. 4 ill. Bibl. 3. Engl.; sum. in Russian.


Structure of space reflactor Force Ring. Sh. Tserodze, E. Medzmariashvili, M. Sanikidze, N. Tsignadze, M. Nikoladze, V. Gogilashvili, E. Logachevi.  Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 28-35, (Engl.).

Is represented the structural scheme of new transforming force ring, which represents consisting from rod elements kinematical chain. Separate sections represent the parallelogram mechanism on which diagonals are installed translational motion two lever group. Each section are rectangular shaped and consists from jointly connected rigid rods with telescope rod located on a large diagonal. As a result would be technical and technological effects that in turn provide the creation of deployable ring that even in the case of large dimensions represent rigid and light-weight structure.  15 ill. Bibl. 9. Engl.; sum. in Russian.


OBTAINING OF THE PERIODICAL PROFILES WITH THE EXACT PITCH BY MEANS OF THE COMBINED PROCESSES OF ROLLING AND DRAWING. J. Lomsadze, T.  Natriashvili , Z. Lomsadze, S.  Mebonia . “Problems of Mechanics”, Tbilisi, 2011, ¹ 2(43),
pp. 36-40, (Engl.).

In article new scheme of technological process for manufacturing of periodic profiles  based  on the combination of rolling and drawing, as well as the rtational construction  installation for its realization is proposed. The   formula to determine the contact stress and deformation of  the metal in the deformation   zone  is proposed. 4 ill. Bibl. 4. Engl. sum. in Russian.


Engineering theory of analysis of multilayer orthotropic axisymmetric shells of medium thickness on complex elastic foundation. J. Bichiashvili.  Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 41-55, (Engl.).

Is developed engineering theory of solutions of analysis tasks of axisymmetric orthotropic multilayer medium thickness shells, located on complex Winkler type elastic foundation that gives the possibility in combination with an iterative technique to solve the problems of such type shells in linear as well as in  nonlinear formulation, without application  of nonlinear differential equations of shell theory. Is defined the possibility of obtaining of analysis results with a high degree of accuracy (from 0.01 and higher), are considered some particular types of shells. 2 ill. Bibl. 14. Engl.; sum. in Russian.


THE LOCOMOTIVE VIBRATORY PROCESSES AND THEIR INFLUENCE ON THE DRIVE TOOTH GEARING. V. Zviadauri, G. Tumanishvili, M. Chelidze, G. Cockhalashvili. “Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 56-62, (Engl.).P

The influence of dynamical loads generated as a result of the railway rolling stock spatial vibrations on the drive transmission is considered in the paper. For solution of the problem a generalized dynamical model of the rolling stock spatial vibratory movement is considered, where the wheel-rail contact and a  motor of the drive are the source of excitation, and as a closing link of the drive tooth of the power flows an engagement of the drive tooth gering is considered. A central link is a pair of the gear-wheels, from which a classical methods a system of interdependent differential equations of the rolling stock and rail vibrations is obtained in the work, that is important for study of simultaneous influence of various parameters on the transmission vibratory movement and load. As a result of computer modeling of the system of equations it will be possible to study an influence of dynamical due to variation of the rolling stack various inertial and geometric parameters on the movement of each gear-wheel and character of their interaction. 2 ill. Bibl. 3. Engl.; sum. in Russian.


improvement of freight transportation by perfection of rolling stock selection methods. O. Gelashvili, N. Butkhuzi. G. Tsertsvadze.  Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 63-66, (Engl.).

In the article is considered issues of improvement of freight road transport efficiency due perfection of rolling stock selection methods. By the motor transport is carried out a variety of cargo transportation that raises the specific requirements for rolling stock. Thus the rolling-stock selection that provides reliable low cost freight traffic and safety, in specific operating conditions, is rather actual. On the basis of analysis of the transport rolling stock selection methodsis defined the great number of indicators, parameters and variables on which basis the decision-making requires the development of special multi-criteria method of evaluation In the work is mentioned taht all models represents the classical transportation problem and its modifications for that are nowadays is developed lot of solution methods and algorithms and is necessary for each model to determine the optimal solution options.  2 ill. Bibl. 3. Engl.; sum. in Russian.


on assesment of Mechanical system’s transient processes. M. Tsikarishvili, M. Mokhevishvili.  Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 67-71, (Engl.).

The paper is to present a mathematical model intended for describing the transients that would originate in some components of both mechanical structures and airspace-engineering systems. Owing to the mathematical model made thereof, a new method of analysis has been developed. It implies determination of the position and intensity of the transients taking place in the components of a system. That is achieved through applying the data obtained with the help of fiber-optic sensors. The analysis cited here proves the adequacy of the mathematical model to the findings of the experimental investigation where analytical preconditions were obtained on the basis of Fourier's spectral analysis. Due to the qualities fiber-optic sensors appear to exhibit, it becomes quite evident that the technical state of the structures under investigation may be controlled continuously throughout their life period. 3 ill. Bibl. 3. Engl.; sum. in Russian.


INTERACTION OF THE TRACTOR DRIVING WHEELS WITH THE SOIL BY CONSIDERING THE RHEOLOGICAL PROPERTIES OF SOILS. R. Makharoblidze, I. Lagvilava, O. Asatiani, A. Kobakhidze. “Problems of Mechanics”. Tbilisi, ¹ 2(43), pp. 72-78, (Engl.).      

The work contains the results of theoretical studies of the process of interaction of the tractor wheels with the soil. A rheological model is used as a law of shear deformation of soils as the principal law of linear deformation. Calculation formulae of tangential traction force and traction coefficient of the tractor driving wheels are deduced. A numerical example and graphs are used to demonstrate that the theoretical results are quite close to the experimental data. The solution to the new questions of the indicators of the traction dynamics, maneuverability and passability of the existing and newly designed tractors and other wheeled power machines needs a further development of the theory of interaction of the tractor driving wheels with the soil.  2 ill. Bibl. 9. Engl.; sum. in Russian.


FEATURES OF ENTROPY CHANGEs AND VIOLATION of SECOND LAW IN LARGE SCALE SYSTEMS. A. Aptsiauri.  Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 79-87, (Engl.).

In the article on basis of energy and momentum conservation laws is indicated that at the large scale heat-insulated stream, in the onset of turbulence process or other relative motions, there is an apparent effect of cooling from without and heat accumulation into kinetic energy, at simultaneously fall of entropy, which contradicts with the requirement of second law.  4 ill. Bibl. 12. Engl.; sum. in Russian.


INVESTIGATION OF THE VARIABLE GEOMETRY ROTOR IN DINAMICS. Î. Rukhadze, R. Turmanidze, R. Bidzinashvili, Å. Rukhadze. Problems of Mechanics”. Tbilisi, 2011, ¹ 2(43), pp. 88-95, (Engl.).

In the article the summary of state of the question of investigation of the rotors with variable geometry parameters (VGR) in dynamics is shown. By calculation and experimental ways are determine the regularities of distribution of induced speeds of the air flow along the span of blades at the increase of twist range. The dependences of the thrust from the change of the rotor diameter range ÷ and the range of twist of blades are established. 9 ill. Bibl. 4. Engl.; sum. in Russian.


THE REFINED MODEL OF PLANE WAVES OF THE IDEAL FLUID IN A BASIN. A. Tvalchrelidze.  “Problems of Mechanics”. Tbilisi. 2011, ¹2(43), pp. 96-100, (Engl.).

There is considered in a given article the mathematical model wave pattern on the sea coastal zone. On the basis of kinematic hypothesis and d’Alembert-Lagrange principle there are derived the one-dimensional equations and boundary conditions with simple mechanical sense. 

The peculiarity of the model consists in fact that with one-dimensional description of motion there are simultaneously considered the extension of motion quantity and moment of fluid mass motion quantity in transverse direction to coast.  1 ill. Bibl. 2. Engl.; sum. in Russian.


calculation of multi-layered spatial systems with discontinuous parameters. Z. Sopromadze. “Problems of Mechanics” Tbilisi. 2011, ¹ 2(43), p. 101-104, (Engl.).

Is stated the method of calculation of multi-layered spatial systems with cuts. The method of cuts consideration is grounded on application of special discontinuous functions that are introducing in initial relations and decision equation as well as in desired solution. The obtained solutions are reducing to easy algorithm and allows by fast-realized programs to define the stress concentration. Bibl. 5. Engl.; sum. in Russian.


Improving of prevention systems for providing vehicles technical state. V. Lekiashvili, M. Zurikashvili, D. Ugulava.  Problems of Mechanics”. Tbilisi, 2011,
¹ 2(43), pp. 105-107, (Engl.).

The method of formation of classification groups for optimization of vehicle maintenance modes is developed. For each group are presented models to determine the optimal periodicity of performing preventive operations. As optimization criterion is assumed level of probability of non-failure operation and minimum of specific cost.  1 ill. Bibl. 7. Engl.; sum. in Russian.