Research OF MANIPULATORs, created by SPATIAL five-bar
mechanism with two degrees of freedom. N.
Davitashvili. “Problems of Mechanics”.
Is stated study of manipulators, formed by spatial five-bar mechanism with two degrees of freedom. For the first time are identified 16 different types of spatial five-bar mechanism of manipulators with taking into account the combinations of rotational, spherical, cylindrical, and spherical with finger and prismatic kinematical pairs. The design of spatial five-RSSRR type manipulator with two degrees of freedom for a given law of motion of robot output point (gripper) is carried out. 9 ill. Bibl. 10. Engl.; sum. in Russian.
OF DYNAMIC AND KINEMATIC precision OF passenger carriages optimal brake
leverage with clearances. G. Sharashenidze, M. akhalbedashvili, P.
Kurtanidze, T. Dundua, L. Balon. “Problems of Mechanics”.
According the developed real dynamic model, for purpose of definition of reaction and friction forces in the joint connections with clearances are considered the equilibrium state of each lever and rod with the view of the impact forces. the values of real dynamic loads are depended on the parameters of generalized coordinates are shown. The analytical expressions for the friction and reaction forces, as well as for the inertial forces and moments of inertia with taking into account the braking force of brake cylinder and the pressing forces of brake shoe on the rolling surface of railcars wheel are obtained. 2 ill. Bibl. 14. Engl.; sum. in Russian.
DUAL TRANSFORMATION DEPLOYABLE
BRIDGE. E. Medzmariashvili, M.
Sanikidze, V. Gogilashvili, N. Tsignadze, L. Filipenko, G. Medzmariashvili. “Problems of
The work overviews research of various types of designs and new systems of construction during spatial transformation for the purposes of choosing the optimal embodiment of the reusable single-span transformable bridge intended for use in extremal circumstances. Transportation and folding/deployment of the bridge over an obstacle are performed by means of a single vehicular and mounting means – tank, motorcar or helicopter. Assembling and dismantling of the bridge require a few minutes and do not require from the driver or operator to leave the vehicular and mounting means. The length of its span in the proposed design is increased up to 48 meters. The folded transport package weight and dimensions are the same of those of existing 24 meters span bridges. Based on the conducted researches, an optimal design of the single-span transformable bridge with corresponding technical characteristics has been elaborated. 6 ill. Bibl. 4. Engl.; sum. in Russian.
INVESTIGATION OF THE FUNCTIONING OF UNITS OF THE ROTORS WITH VARIABLE
GEOMETRY PARAMETERS. R.S. Turmanidze,
O.G. Rukhadze, E.O.
Rukhadze. “Problems of
In the article is carried out a short
review of state of the issue to creation of the airplanes with vertical takeoff
and landing (VTOL). On the basis of scientific-research and experimental
designing works is created a special equipment for investigation of the rotors
with variable geometry parameters (
Calculation of orthotropic two-layered constant and
variable thickness plates by method of initial parameters. Part 1. Calculation
of orthotropic two-layered constant thickness plates by method of initial parameters. G. Bichiashvili, J. Bichiashvili, Z. Bichiashvili. “Problems of
In article is carried out the calculation of round orthotropic single-layered plate rigidly fixed on the contour, non-located on the elastic (free) variable thickness foundation with radius a=100 cm and loaded by uniformly distributed vertical loading of intensity of load q=104 Pa perpendicular of it’s median surface. Calculation is carried out by the offered method [1,4] on the basis of method of initial parameters. The number of sites Ê=400 and radius of the internal rigid site of plate r0=0.25 cm. are constructed the stresses distribution and for various points of plate’s cross-section. Mechanical properties of layers materials are different. 4 ill. Bibl. 5. Engl.; sum. in Russian.
Calculation of orthotropic two-layered constant and
variable thickness plates by method of initial parameters. Part 2. Calculation
of orthotropic two-layered Variable thickness plates by method of initial parameters. G. Bichiashvili, J. Bichiashvili, Z.
In article is carried out the calculation of round orthotropic two-layer plate rigidly fixed on edge, with variable thickness layers, non-located on the elastic (free) foundation with radius a=100 cm and loaded by uniformly distributed vertical loading, intensity q=104 Pa of perpendicular it surfaces. Calculation is executed by an offered method [1, 4] on the basis of a method of initial parameters. The number of sites K=400 and radius of an internal rigid site of a plate r0 =0,25 cm. Are constructed diagrams of factors Q, Mr, Mt, W, σr σt, for various points of cross-section section of plate. Mechanical characteristics of materials of layers identical, but oriented in different. At the considered plate the relation for different layers are various, due this longitudinal forces Nr and Nt at bending by loading q are not equal zero. 3 ill. Bibl. 6. Engl.; sum. in Russian.
THE T-S DIAGRAM AND FRICTION. FALLING OF ENTROPY
AT ACCELERATION OF GAS IN CHANNELS. A. Aptsiauri. “Problems of Mechanics”.
In article, on the basis of laws of energy and a pulse conservation is shown, that at acceleration of thermo isolated stream in real conditions in spite of the fact that, as a result of friction, total value of entropy grows, on an initial site of acceleration it should decrease, that contradicts with the requirement of the second law. The principle of construction of diagrams in view of presence of dissipation is offered. 9 ill. Bibl. 5. Engl.; sum. in Russian.
OF ASSEMBLING AN ADAPTED SELF-PROPELLED CHASSIS ON
The article considers the methods to define the normal reaction for the wheels of adapted self-propelled chassis in case of balance suspension of the driving tandem wheels. The calculation formulae for the normal reactions for the front guides and driving wheels are deduced. It is established that the summary normal reaction on the truck is distributed equally between the rear and front tandem wheels what will have its impact on the traction characteristics of the running system. The normal reactions for the wheels are determined by considering the assembly of the operating equipment what allows identifying the optimal locations of the technological working organs along the girders of the chassis by considering the minimization of the pressure of the wheels on the soil. 2 ill. Bibl. 5. Engl.; sum. in Russian.
Study of the automobile braking dynamics in the case
of braking by the high-effective motor
brake. B. Kordzadze,
T. Natriashvili, R. Demetrashvili. “Problems of Mechanics”.
The accomplished work confirms that for comparison of braking properties of two automobiles it is expedient to introduce by analogy of the automobile dynamic factor, the automobile braking factor, with the help of which it will be possible to determine theoretically such important braking parameters as braking path and braking time are. 7 ill. Bibl. 2. Engl.; sum. in Russian.
TO THE THEORY OF TEA LEAF TWISTING PROCESS: THE DEGREE OF THE TEA MASS
TWISTING. A. Tvalchrelidze, B. Kankadze.
“Problems of Mechanics”.
Rheological model of the tea mass must underlie theoretical researches of the tea leaf twisting process - one of the main technological processes in the BaiHua tea manufacturing. One of the state parameters of tea mass in this process is a degree of twisting. There is considered in a given article one of the options for introduction of such parameter. Bibl. 1. Engl.; sum. in Russian.
On issue of development of plate’s design procedure on axisymmetric
fluctuations. Z. Bichiashvili,
J. Bichiashvili, G. Bichiashvili. “Problems of Mechanics”.
In article is proved that formulas for definition of natural resonant frequency of circular and ring, as well as square plates are not represented as exact that is caused by various values of Poisson's ratio for different materials. The improvement of the classical theory of plates by the taking into account of results of the researches, carried out by authors is recommended: influence of sites number on plates calculation results on axisymmetric fluctuations; influence of Poisson's ratio on plates calculation results on axissymmetric fluctuations; influence of shear strain and masses rotary inertia on plates calculation results on axisymmetric fluctuations, etc. Bibl. 9. Engl.; sum. in Russian.