¹ 2(31), 2008
Investigation of a plane RRRRT type five-link hinged mechanism with
two degrees of freedom. N.
Davitashvili. “Problems of Mechanics”.
Investigation of a plane five-link hinged mechanism with two degrees of freedom with four rotary pairs and with one translational pair (RRRRT) has been conducted. The positions, velocities and accelerations of output links and their points are determined. The equation of a trajectory of a center of connection hinge of connecting rods of the five-link mechanism, when one of two input links accomplishes rotary motion and another - back-and-forth motion. The highest order of the equation of a trajectory is determined and the ways of solution of synthesis problems for mentioned mechanisms according to given trajectory given. 4 ill. Bibl. 17. Engl.; summ. in Russ.
AND CALCULATION METHOD FOR ROPE – ROD STRUCTURES. D. Pataraia. “Problems of Mechanics”.
In this paper the method of simulation and calculation of complex rope – rod structures, membranes and massive bodies basing on the discrete representation of rope and rods in the form of the set of point masses, springs and dampers is given. For its realization the algorithm, which leads a computer model of object from initial state to equilibrium state, is developed. Then, on the basis of corresponding geometry of a body, the values of efforts, displacements and other unknown physical parameters are determined. 10 ill. Bibl. 9. Engl.; summ. in Russ.
Deployable 48 m span
assault bridge. E.
Medzmariashvili, M. Sanikidze, V. Gogilashvili, N. Tsignadze, G. Bedukadze, G.
Medzmariashvili. “Problems of Mechanics”.
In work are considered single-span, multiple application, extreme bridges, which collapsible internal structure meets to conditions of its transportation and installation on a site. Such bridges are installed on the single transport- installation carrier - truck, tank or helicopter. It is laid and removed from surmount obstacle in the shortest term. During its installation and dismantle people do not leave transport-installation carrier. At the same time in a structure of the presented bridge, from one side is increased the span from 24 meters up to 48 meters and on the other side, the weight and overall dimensions of its folded package are left the same as for existing 24 meters span bridges. 18 ill. Bibl. 5. Engl.; summ. in Russ.
LOADING AND THE SLIDING DISTANCE OF A
WHEEL/RAIL CONTACT. G. Tumanishvili, M.
Friction plays a key role in deterioration of wheels and rails, in fatigue failure of surfaces, in derailment, in the energy consumed on movement of a train and in other operational problems. Premature damageability of rails and wheels, as well as derailment, represents serious problems of a railway transportation. The overload of operating conditions of machines, increase of capacities and temperatures strengthens importance of prevention problem of the specified phenomena. The processes proceeding in a zone of contact of rails and wheels influence a wide spectrum of the phenomena. Various aspects of these processes are insufficiently investigated and do not give directly to an estimation. Our research focuses on the investigation of sliding distance and thermal loading of wheel/rail contact. 5 ill. Bibl. 4. Engl.; summ. in Russ.
CALCULATION OF THE INTERFACED THERMODYNAMIC
CYCLES - PARADOX OF EFFICIENCY. A. Aptsiauri. “Problems of
In the work the original method of interface of cycles of the thermal pump and the thermal engine is offered. The combination of cycles allows to receive heat from environment. By thermal calculation quite concrete theoretical indicators of each process are defined, the thermal balance of cycles is resulted. It is shown that engine work completely balances mechanical energy which consumes the thermal pump. The attention to additional, detailed studying of non-stationary processes of heat accumulation and regeneration is paid that will allow to draw a definitive conclusion on a reality of such project. 3 ill. Bibl. 5. Engl.; summ. in Russ.
WITH THE FLOW OF CONDUCTING FLUID IN CIRCULAR PIPES WITH FINITE CONDUCTIVITY UNDER UNIFORM TRANSVERSE
MAGNETIC FIELDS. V. Tsutskiridze, L.
Jikidze. “Problems of Mechanics”.
The flow of conducting, viscous fluids in circular pipes under transverse magnetic field is studied theoretically. The correlation of Hartman’s figure, Poisale’s figure, Reynold’s figure and conductivity of walls are considered. Bibl. 8. Engl.; summ. in Russ.
SURFACE LAYERS DESTRUCTION OF FRICTION BRAKE MATERIALS. N. Meliksetyan. “Problems of
The surface layers destruction studies results of brake friction materials on rubber, binder and multifunction resins base have been produced depending on surface friction temperature. Applying the methods of raster electronic microscopy, X-rays diffraction, and dilatometer analysis it is established that the mechanism of high temperature wear destructions of the materials’ surface layers corresponds to the delaminating mechanism of wear. 4 ill. Bibl. 5. Engl.; summ. in Russ.
SICKNESS CAUSED BY A MANUAL MECHANIZED TOOL AND THE MEASURES OF PROTECTION. M. Dzhikia, A. Neverov, N. Machavariani, G.
Shuradze, S. Metonidze. “Problems of Mechanics”.
The reasons and symptoms of vibration sickness caused by a manual mechanized tool are considered. The results of experiment on the study of transmission of oscillations from the source of vibration to the arm and head of workers are given, and also the calculation formula of the efficiency of external vibration protection on a basis of the values of impedances of a hand tool, hands of a man and external vibration protection. 3 ill. Bibl. 5. Engl.; summ. in Russ.
HEAT EXCHANGE IN
THE MAGNETIC FIELD. V. Tsutskiridze.
“Problems of Mechanics”.
The heat exchange of steady laminarly moving incompressible electro-conductive liquid in a channel with isothermal walls formed by parallel plates is considered. The influence of transverse uniform magnetic field on the heat exchange with constant flow rate of medium and constant pressure drop is shown. The essential dependence of the temperature of a fluid flow and heat exchange Nusselt’s number on the value of external magnetic field and electrical conductivity of the walls of a channel is revealed. Bibl. 5. Engl.; summ. in Russ.
STRESSES IN THE BUTT JOINTS OF EXTERNAL AND INTERNAL LOAD-BEARING WALLS OF A
In the article the developed theory of calculation of dynamic shearing stresses in the butt joints of load-bearing longitudinal and transverse walls under action of a sudden horizontal load is given. The calculation expressions allowing optimizing the parameters of bearing-structure of large-panel buildings are obtained. 2 ill. Bibl. 2. Engl.; summ. in Russ.
about the method of calculation of the hoses loaded with
concentrated forces. Z. Arkania, A. Badzgaradze. “Problems of
Present work deals with the method of calculation of hose in the case when concentrated forces act on it and inner stream of liquid is considered. Stretching of the hose in the application points of concentrated forces sharply changes, which considerably influences on liability of the construction. Change of hose stretch is caused also by the stream of liquid that flows in the hose. In the work a method of calculation of enough accurasy is described, where above factors are taken into consideration. Above mentioned method is realized in Electric Calculating Machine and it is obtained concrete results. On the bases of these results corresponding recommendations are done. They must be considered when projectiong the constructions. 4 ill. Bibl. 3. Engl.; summ. in Russ.
AND DEVELOPMENTS IN THE
aspects of use of New Austrian method in the building of tunnels in
Synthesis of Control With Beforehand Set
Zero Spectrum in the Stationary Integro-Differential Equation of order n. F. Grigoryan. “Problems
The one-dimensional control choice problem with the beforehand set zero spectrum in stationary integro-differential scalar equation of the order n is considered for the case when the quantity of regular inputs is equal to one. Bibl. 5. Engl.; summ. in Russ.
A NEED FOR ROLLING STOCK IN THE PROSPECT.
Z. Meskhidze, G. Telia, A. Sharvashidze,
K. Gudiashvili. “Problems of Mechanics”.
In the article we consider an urgent question of exploitation work of railroads and determination of required rolling stock in the prospect. Formulas for analytical calculations and corresponding graphs of dependences are recommended. 9 ill. Bibl. 6. Engl.; summ. in Russ.
OF FUNCTIONAL ABILITIES OF LOCAL DIAGNOSTIC SYSTEM LDS BY MEANS OF A CLASSIFIER
OF RAIL CHAINS. N. Mukhigulashvili, M.
Papaskiri, B. Elbakidze, T. Rokhvadze, D. Iobidze. “Problems of Mechanics”.
The functional abilities of local diagnostic system LDS is analyzed consistently. The automatic diagnostic system developed for rail chains state completes the functional abilities of local diagnostic system LDS, which cannot store full information about the state of rail chains. Built by mathematical model, LDS system can determine the operational modes of rail chains and the form of damage in a rail chain by the values of two parameters measured in the end of a rail chain. 2 ill. Bibl. 7. Engl.; summ. in Russ.
THE METHODS OF
CALCULATION OF DAMAGED AND REINFORCED FASTENINGS OF TUNNELS. V. Tarkhnishvili, N. Maisuradze. “Problems
The method of calculation of damaged and reinforced circular form concrete fastenings is developed. The implementation of the received results for non-circular form fastenings is shown. The problem is resolved by use of the functions of complex variables. 4 ill. Bibl. 5. Engl.; summ. in Russ.
research of the compound cylindrical STRUCTURE, transient wave process. L. Verulashvili, L.
Balanchivadze, G. Gureshidze. “Problems of
In this paper it is considered the question of change of a component of cylindrical shell when the left basis of a shell receives jumping change in loading by the exponential law. Also it is considered caused by non-symmetrical dynamic loadings. The three-layered Samarski difference scheme is plotted. The convergence criterion of the scheme is restored. The numerical analysis of wave process is lead by algorithm. The plotted curves clearly indicate on possibility of buckling failure of structure due longitudinal impact. 4 ill. Bibl. 4. Engl.; summ. in Russ.
ON THE STABLE LOCKING IN TO SYNCHRONISM OF THE
Conditions of achieving stable locking in to synchronism of the electric drive system have been discussed for improving the starting regimes and preventing the electric drive system from damages which can be caused by the motor fall from synchronism due to influence of different factors. 1 ill. Bibl. 5. Engl.; summ. in Russ.
Elaboration of auromated system for
calculation of optimal modes of milling. L. Tediashvili. “Problems of
The structural scheme of parametrical optimization for calculation of modes of milling is suggested, the means of its implementation are considered. The technique of parametrical optimization is determined in the article. 1 ill. Bibl. 5. Engl.; summ. in Russ.