#4(37), 2009
SUMMARIES
NEWSLETTER OF
IFToMM. “Problems of Mechanics”.
kinematic analysis and precision of sewing-machine thread takeup linkage
mechanism. N.
Davitashvili, Kh. Khabuliani. “Problems of Mechanics”.
The solutions
of kinematic research and kinematic precision problems of the light industry
sewing-machine thread takeup linkage mechanism (together with carrying needle)
are given. The kinematic parameters of output links and their points are
defined. With the account of primary (technological) errors are found the
positioning errors of output links and their points, as well as for whole
mechanism. By computer machinery is solved the numerical example which results
is given by diagrams. 3 ill. Bibl. 10. Engl.; sum. in Russ.
DISTRIBUTING OF PRESSURES ALONG PRESS
CHAMBER OF SCREW WORKING ORGAN. R. Makharoblidze, O. Tedoradze, M. Gachechiladze.
“Problems of Mechanics”.
Is stated the theory of screw working organ compression chamber design
of distributing of pressure and force of friction along the chamber.
Calculation formulas are shown out for determination of pressure on the bottom
of chamber mobile part and force of friction of material at the walls of
immobile and mobile chambers. It is set that force of friction depends on
attitude of perimeter of chamber cross-sectional toward his area. Most rational is the round section of
chamber. From point of energy consumption on overcoming of friction the
chambers of large section are more expedient.
3 ill. Bibl.3 Engl.; summ. in Russ.
MODELING of chain structures mechanisms motion with elasto-friction
links. N.
Baidarashvili,
The
long-length chain system with elastic-frictional links is considered. The
dynamic analysis of system is carried out on the presented basic contour on the
basis of the nonlinear differential equation. Spectra of frequencies, dynamic
transfer functions are defined at variation of geometrical parameters for the
considered long-length system. 3 ill. Bibl. 4.
Engl.; sum. in Russ.
ELABORATION OF THE MODEL OF LOGISTICAL SYSTEM “ECOLOGICAL SAFETY OF
AUTOMOBILES — DIESEL OIL PROPERTIES”. T.
Natriashvili, D.Iosebidze, O. Gelashvili, G. Abramishvili. “Problems of
Mechanics”.
On the basis of results of existent researches conceptual relations
between quantity of harmful exhausted products of automobile diesel engines and
indices of diesel oil such as : fractional composition, cetane number,
viscosity, density, ashiness, cokiness, acidity, contents of sulphur and actual
pitches, etc, are established. Significant influence of the oil basic indices
(temperatures corresponding to distillation of 50%, 90% and 96%, cetane number,
etc.) on the mentioned automobile ecological indices is confirmed. A model of
logistical system of the relation between automobile ecological safety indices
and diesel oil properties is elaborated taking into account the revealed
conformities with a law. Regulation of magnitudes of the model components
ensures retaining of the planned level of automobile ecology and enables also
to reveal perspective ways and modes for its rise. 7 ill. Bibl. 4. Engl.; sum.
in Russ.
EQUILIBRIUM EQUATIONS OF THE FINITE ELEMENT IN THE THEORY OF SHELLS WITH
THE USE OF SEVERAL BASIC SURFACES. A. Tvalchrelidze, K. Tskhakaia. “Problems of
Mechanics”.
Finite
element method gives the effective method of algorithms construction for
boundary-value problem of the theory of shells with the use of several basic
surfaces. There are derived in a given article the equilibrium equations of the
finite element within the framework of theory in general and linear versions.
These equations are the basic equations in the finite-element settings with
numerical solution of different applied problems of the calculation of shell
constructions. Bibl. 2. Engl.;
sum. in Russ.
ABOUT AN
In work, on
the basis of theoretical research is
shown that, in local area of any
system the process can occur with
reduction of entropy and increase of order only because of action of
accidental, locally natural and external forces
and also in that cases when in such system purposeful action of the intellectual subject
takes place, thus the charge of physical energy is obligatory only in that case
if in this process is necessary to overcome the resistance
of physical bodies. Hence, as the basic
obstacle, for achievement of maximal efficiency, not temperature limits but
physical properties of bodies are considered. Bibl. 6. Engl.; sum. in Russ.
Application of vibration in the wall
plastering-covering and cleaning works. M. Chelidze, V. Zviadauri, G.
Tumanishvili, A. Gogava. “Problems of
Mechanics”.
Presented possibility of realization of the
fixing of the fluid plastic material and its compactions on vertical plane be
means of vibration. Vibro-processing reduces to minimum air bubbles in the
inficted layer and compacts it. Because of reduction air bubbles occurs:
reduction off the volume freezing water in concrete covering layer, destruction
covering layer wall and increased contact covering
layer surfaces with the wall. 5 ill. Bibl. 8. Engl.; sum. in Russ.
THE THERMAL LOADING OF MICROASPERITIES OF
INTERACTING SURFACES.
T. Buchukuri, G.
Tumanishvili. “Problems
of Mechanics”.
The discrete
parts of contact zone at friction are regarded as the primary heat
sources. The process heat distribution in micro asperities mathematically
modeled by the three-dimensional boundary value problem. Solution of
the problem is obtained in expanded form. Calculations based on
the obtained solutions allow to compute the temperature field in
micro asperity and receive more detailed picture of heat
absorption by bodies and surroundings and estimate thermal
loading of contact with regard to environmental characteristics. 1 ill. Bibl. 7.
Engl.; sum. in Russ.
mathematical model of technological parameters definition for footwear
test device. T.
Maglakelidze, M. Zakaraia. “Problems
of Mechanics”.
In work are presented the result of short review of contact problems. It
is received at research interaction of isotropic, anisotropic and non-uniform
materials. The principal attention was given to those mainstreams, which were
allocated at research of contact problems for above specified materials and
structural components. 4 ill. Bibl. 2. Engl.;
sum. in Russ.