**¹****4 (45), 2011**

**SUMMARIES**

NEWSLETTER
OF IFToMM, pp. 5-12.

Dinamical
research of manipulator with taking into account elastic links with
concentrated masses.** N.
Davitashvili. **Scientific Journal of IFToMM “Problems of Mechanics”.

Is stated the dynamical
analysis of planar manipulator with closed chains with taking into account
elasticity of links with concentrated masses. For carrying out the comparative
analysis dynamical research is conducted with rigid links as well as with
elastic ones. The method of definition of coefficient compliance coefficient of
manipulator is given. The describing motions of motors, input links and
concentrated masses are obtained. There are preconditions for study of
oscillating process of gripper. As examples are given results of synthesis of
manipulator, which gripper can move on straight line.* *5 ill. Bibl. 11. Engl.; sum. in Russian.

On the
Mechanics of Valve Spring Rotation in Internal Combustion Engines depending on
the Rotational Speed of the Camshaft. Peter Taubmann, Igor Zeidis, Klaus Zimmermann,
Hans-Juergen Schorcht, Ulf Kletzin. Scientific Journal of IFToMM “Problems of
Mechanics”.

From practice, it is known that high dynamic stressed valve
springs rotate around their axis. The direction of rotation depends on the
excitation frequency. Therefore the direction of rotation changes during the
usage of valve springs for example in a modern combustion engine. This article
presents an analytical expression for the angular velocity of the spring in the
stationary regime using a mechanical model with two degrees of freedom. The
results are obtained by asymptotic methods with the assumption of small
friction between valve spring and valve spring seat.

An experimental setup allowing the measurement specific
parameters of the spring rotation was developed for the evaluation of the
analytical and numerical results. Finally the described phenomenon is discussed
in the global context of the dynamic behaviour of mechanical systems near the
resonance. 11 ill. Bibl. 8. Engl.; sum. in Russian.

characteristic differential equations 0f additional
Break-contact-break (B_{1}C_{2}B_{3}) motion of optimal
brake leverage transmission.** G.
Sharashenidze, T. Natriashvili, M. Glonti.
**Scientific Journal of IFToMM “Problems of Mechanics”.

In the work is presented
differential equations of additional motion of passenger rail-cars optimal
brake leverage transmission, when from three joint connections in the first is
free motion, in the second - contact, and in the third – free motion. At
generation of differential equations are applied Lagrangian equation of second
order and dynamical model of optimal leverage transmission. The dynamical
loadings of transmission links an impact of brake force on whole system are
taking into account. The generalized force represents the function of existing
in joint connections reaction and friction forces and with geometrical
parameters of transmission defines the structure of differential equations of
additional motion.* *1 ill. Bibl. 13. Engl.;
sum. in Russian.

MODAL ANALYSIS OF THE ELEMENTS AND
SUB-ASSEMBLIES OF CUTTING-OFF MACHINES WITH ENDLESS BANDSAW. **W. Kalinski, J.
Wojnarowski. **Scientific Journal of IFToMM “Problems of Mechanics”.

The excited mechanical vibrations affect
unfavourably the efficiency of the process as well as the tool life of the
teeth of the saw and the state of the surface of the cut object. The paper
presents the results of measurements of the acceleration of vibrations in
selected sub-assembles of the cutting head, as well as the results of modal
analysis, curried out in order to identify the mechanical properties of the
band-saw. 10 ill. Bibl. 5. Engl.; sum. in Russian.

DETERMINATION
OF THE DEFORMATION ZONE PARAMETERS FOR
LONGITUDINAL TUBE ROLLING IN THE **R.
Adamia, T. Natriashvili, S. Mebonia, M. Mikautadze. **Scientific Journal of IFToMM “Problems of
Mechanics”.

In
article the main deformation and forces
parameters of the deformation zone for longitu-dinal tube rolling in round pass on the drawn back
conical mandrel is determined.
Received dependences allows
to calculate above mentioned parameters at the designing of the
tecnologi-cal process of the tube rolling. 3 ill. Bibl. 5. Engl.; summ. in
Russian.

Experimental
research reflecting mesh of reflector. **E. Medzmariashvili,**** O.
Tusishvili****, M. Sanikidze, ****N. Tsignadze, G. Gratiashvili, G.
Tabagari, S. Nemsadze, I. Gobejishvili****. **Scientific Journal of IFToMM
“Problems of Mechanics”.

The work is intended to reduce elasticity, arrangement of tensioners and
to experimental research of its tensioning force. Here is determined average
meaning of mesh reduce elasticity, also the dependence nature among tensioning
force and tangency points of displacement of tensioners on mesh. 7 ill. Bibl. 3. Engl.; sum. in Russian.

operational characteristicS of TANDEM-wheeled TRACTOR
aggregate on SLOPE. **R. Makharoblidze, I. Lagvilava, O. Asatiani, A. Kobakhidze. **Scientific
Journal of IFToMM “Problems of Mechanics”.

Is
given the theoretical analysis of wheel’s skid impact on lateral displacement
of the tandem-wheeled tractor aggregate on slope. Is derived a formula for calculation
of lateral displacement of aggregate in a function of displacement across
the slope. This gives the possibility to analytically determine the effect
of lateral skid and angle of slope on such operational characteristics, as
pulling force and pulling power of tractor, the coefficient of utilization
of pulling force, the actual speed of tractor, coefficient of utilization of
speed, time, etc. It is shown that application of experimental
tandem-wheeled drive on tractor reduces lateral skid of the aggregate on a
slope and therefore improves operational characteristics. Results of the
study would be applied the planning machinery works on the slope. 2 ill. Bibl. 3.
Engl.; sum. in Russian.

Transformation
of deployable bridge mechanisms. **V. Gogilashvili,**** ****E.
Medzmariashvili, M. Sanikidze, ****G.
Medzmariashvili****. **Scientific
Journal of IFToMM “Problems of Mechanics”.

Paper discuss the force
analyses of transformation of deployable bridge mechanisms, e.g. –
transformation of bridge mechanisms on time of contour deformation and, beat
and damping on last stage of transformation. Received results are giving
possibility to build an image of system transformation for the last stage and
discuss about dynamic process of complete system. 5
ill. Bibl. 4. Engl.; sum. in Russian.

RESULTS OF CALCULATION OF COMPOSITE FUSELAGE AIRCRAFT
BASED OSCILLATIONS ARISE DURING TAKEOFF AND CREEP. **A. Dumbadze, Yu. Kanchaveli.** Scientific Journal of IFToMM “Problems
of Mechanics”.

Optimal values of outer radius, area and bending
stiffness of the cross sections of
carbon-fiber fuselage sections of CMU-1 for a reinforcement *
*, taking into account creep, random, and other factors
causing variations (large roughness of the runway, a gust of wind during
takeoff, a large gradient atmospheric pressure and temperature, etc.).
Accounting for creep and vibrations arising in the fuselage of the main
passenger jet made of carbon fiber CMU-1 will lead to safer, fatigue and noise
fuselage, as well as its life. 2 ill. Bibl. 6. Engl.; sum. in Russian.

mode
of deformation of double curvature
depressed shell with cut.** G. Kipiani,
F. Verulashvili, M. Todua, G. Nozadze. **Scientific
Journal of IFToMM “Problems of Mechanics”.

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.*
*2 ill. Bibl. 3. Engl.; sum. in Russ.

equation for entropy of open
non-equilibrium systems **A. Aptsiauri. **Scientific
Journal of IFToMM** **“Problems of
Mechanics”.

In the work
are considered the features of entropy change in open and closed thermodynamic
systems, in the presence of mechanical and thermal disbalance. It is shown that
in contrast to closed systems, in open thermodynamic systems, surface effects
would leads to a decrease in entropy that is contrary to the principle of
entropy steady increase in the heat-insulated systems. 4 ill. Bibl. 5.
Engl.; sum. in Russian.

THE
MATHEMATICAL MODELING OF THE MIGRATION OF POLLUTANTS IN SUBTERRANEAN WATERS. **K. Tskhakaia, M. Khetsuriani. **Scientific
Journal of IFToMM “Problems of Mechanics”.

* * There is considered the mathematical modeling
of the planned filtration flows of subterranean waters with the existence of
water intake for the purpose of determination of pollutants’ migration
directions. There is shown that the volume of the water intake exercises a
significant influence on possibility of penetration of pollutions into the
water intake area. 4 ill. Bibl. 2.
Engl.; sum. in Russian.

limiter - absorber of axial movement in running gear
of new type gantry crane.** m. Shilakadze, V. Kartvelishvili, M. Barbakadze, D. Bakradze,
I. Jamburidze.
**Scientific
Journal of IFToMM “Problems of Mechanics”.

In
the article is stated the specific solution of improve of reliability process
in running gear of gantry cranes at its operating process. In particular, is
considered and grounded the advisability of application of ring springs in role
of absorber in the possible axial displacement originated at operating process
of the crane with modernized running gear. The calculations are carried out. 1 ill. Bibl. 4. Engl.; sum. in Russian.

THE WEAR OF ALUMINIUM DUCTILE IRON DURING DRY FRICTION.** N.
Khidasheli, G. Beradze, G. Khvichia.
**Scientific Journal of IFToMM “Problems of Mechanics”.

In the present work there are given the results of experimental
investigations of contact fatigue and the wear of deformable high strength
austempered ductile irons - ADI class aluminum cast iron depending on the phase
ratio in metallic matrix. The wear rolling and rolling with creep tests carried
out on the specimens tempered till different levels of hardness showed strong
dependence of contact fatigue and the wear on the amount of retained austenite
in the samples with optimal ratio, required for keeping the high wear
resistance of wearing surfaces, of bainite and martensite phase components in
the matrix structure. 2 ill. Bibl. 8. Engl.; sum. in Russian.

On
studying of dynamics of electro hydraulic control systems course and position
of the vessel.** T.
Mchedlishvili, V. Kiria, K. Amkoladze, R. Diasamidze. **Scientific
Journal of IFToMM “Problems of Mechanics”.

Control systems of course and position of the vessel,
ensuring performance of fundamental problem of navigation that consists in the
precise and safe ship control in accordance with the assigned task and
specified quality criteria, represents between marine automated drives the most
complicated multiple connected multi-mode regulatory system. In connection with
the above mentioned is very urgent task of improving the performance of dynamic
studies of considered system. In this paper are considering the problems of
constructing the initial laws for the application of method of synthesis by a
given transition processes.
1 ill. Bibl. 4. Engl.; sum. in Russian.