Yevgen Gorokhov a, Volodymyr Vasylev a, Sergey Kuznetsov a, Igor Garanzha a,
Eduard Lozinsky a, Roman Pavlovsky b, Alexandr Shcherbonos b
Procedure of definition of geometrical parameters constructions of selffsupporting polygonal poles taking into account regulation natural and forced os-fcillations
Donbas National Academy of Civil Engineering and Architecture
National Aviation University
Abstract.In this paper, technique for the determination of geometrical parametres of polygonal bent poles (PBP) of isolated structures is given and to intended to escape possibility situation of a wind resonance on different builtup territory. The main description of PBP constructive form is contains with indicating the necessary typically sizes. The broad scope application of PBP metal structures (especially noted application in power lines) is confirmed research relevance and in connection with this stress-strain state under the correct wind load. The peculiarities of the process wind-stream for cylindrical structures in different Reynolds number (Re) flow are described. The vortex wake mode criteria basic is experimentally determined for PBP: vortex shedding frequency (fв = 30…40 Hz); Strouhal number (Sh = 0,108…0,152) at number of faces (n = 6, 8, 10 and 12). In the experiments have been established dependence between criteria Reynolds number, Strouhal number and number of faces, wind velocity (Vi) for isolated PBP structures.
Keywords: polygonal bent poles, wind load, vortex wake mode, wind resonance, wind tunnel, Reynolds number, Strouhal number, vortex shedding frequency, fast Fourier transform.
Volodymyr Kushchenko, Alexander Nechitailo
Analysis of the mode of deformation of the joints of guide pulley resting on shaft sloping headgear structures
Donbas National Academy of Civil Engineering and Architecture,
Abstract. The paper is about the results of the analysis of the mode of deformation of the joints of guide pulley resting on sub-pulley structures of a shaft frame-type headgear which is presently under operating conditions. The analysis was done by the design model consisting of plane and solid finite elements and which was realized in the program «LIRA». Due to the numerical results, there were revealed the regularities of local stresses distribution under a guide pulley bearing; parameters of a plane stress under both emergency and normal working loads were found out. On the numerical simulation the guidelines to improve the construction of the joints of guide pulley resting on the sub-pulley frame-type structures were worked out. In whole, the results obtained are the base to improve the engineering procedures of designing steel structures of shaft sloping headgear.
Keywords: shaft frame-type sloping headgear, sub-pulley structures, joint of a guide pulley resting, design diagram, mode of deformation, local stresses.
Ioury Martynov, Yury Lagun, Vitali Nadolski
The shear resistance models of steel memberstaking into account the web buckling
Belarusian National Technical University
Abstract.The engineering design methods of shear resistance of steel members which are used in the normative documents of UIC, Europe and North America were considered. The factor analysis of the shear resistance models was done. The general model’s parameters (the relative slenderness of web and the shear resistance models of steel members) were reduced to a common form to compare them numerically. The analysis of limits of relative slenderness of absolutely stable web of steel members was done. The features, the qualitative and quantitative differences of the shear resistance models were revealed on the received results. The conclusions of the necessity of further research into the improvement of the engineering design method of shear resistance and into developing of requirement to the limit of relative slenderness of absolutely stable web of steel members were drawn.
Keywords: shear resistance, web buckling, web post buckling work, resistance models.
Yaroslav Nazim, Oleksii Brianskyi
Estimation of resource of conductor/clamp systems for overhead lines at galloping of conductors
Donbas National Academy of Civil Engineering and Architecture
Abstract. Questions of estimation of resource of conductor/clamp systems for overhead power lines (OPL) at galloping of conductors is examined in the article. The certainly-element model of fittings was created by means of design in the SolidWorks. The static calculation of fittings on loading from galloping of conductors exposed large stress in the area of contact of U screw-bolt and staple, and also in the places of bend of screw bolt and in the area of the first coil of screw-thread. Stress on some areas exceed the limit of fluidity in 2 times. The executed calculation on the fatigue of fittings allowed to set that the tireless resource of knot at the most unfavorable terms of frequent galloping can make no more than 1 year of work. Offered to recommendation on the increase of reliability of conductor/clamp systems.
Keywords: overhead power lines (OPL), conductor/clamp systems, resource, fatigue, tensely-deformed state, numeral design.
Anton Tanasoglo
Refinement of a dynamic factor of dead-end support of optl 110 kv for action of the pulse component of wind loading
Donbas National Academy of Civil Engineering and Architecture
Abstract.There is analyzed dynamic calculation of a metal dead-end support of overhead power transmission lines (OPTL) 110 kV for action of the pulse component of wind loading. The purpose of dynamic calculation of metal supports of OPTL for wind influence is the analysis of the established fluctuations of a support in a wind flow. Thus characteristics of central displacements, internal forces and stresses are defined in finite elements (lattices and belts) separately from action of average and pulse components of wind loading. There is given a design procedure and design dynamic data of a rod of equivalent stiffness. An attention is given to the basic problems which can occur during the transition from a support spatial pattern model to the rod of equal cross section. There are considered a number of problems connected with a refined specification of a dynamic factor. On the base of design and extension of the results there was thoroughly compared received dynamic factors on sections of a dead-end support with dynamic factors of a rod of equivalent stiffness for action of the pulse component of wind loading.
Keywords: overhead power transmission line, metal support, dynamic factor, spatial model, rod of equivalent stiffness.
Vadim Gubanov, Iryna Mezhynska
Improvement of wind pressure calculation of guyed masts considering their location on buildings roofs
Donbas National Academy of Civil Engineering and Architecture
Abstract. Guyed masts for cellular nets are often on roofs of buildings placed. This article reviews the research results of wind stream properties over a building surface in the wind tunnel. Importance of this research is highlighted. The open soaking-up wind tunnel of short type was for the experiment used. An overview of the main parameters of a wind tunnel and of the used measuring devices is given. Measurements of wind pulsing speeds without the building model and with the considered model of a building were carried out. There are the profile of average speed of a wind, the profile of intensity of turbulence, the profile of spectral density for all high-rise points of a profile depending on frequency, the profile of specifying factor of average wind speed amplification received. Improvement of a wind pressure calculation procedure for the guyed masts located on a roof of buildings taking into account caused by own aerodynamic properties wind pressure increase over a building is offered.
Keywords: guyed mast, basic building, laboratory experiment, wind tunnel, speed of a wind, design procedure of wind pressure.