E.V. Gorokhov, S.N. Bakayev, Ya.V. Nazim, V.V. Morgay, M.S. Popov
Failure cause and consequence analysis at the highb voltage (330 kV) line sections of the dzhankoy local electrical power station of the Crimean electrical power system of the NEC “UKRENERGO”
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article is devoted to the problem of power supply reliability in the Autonomous Republic of Crimea illustrated by fact-finding of the resonant failures of the overhead high-voltage (330 kV) “Kakhovskaya – Dzhankoy”, “Kakhovskaya — Ostrovskaya” and “Melitopol’skaya — Dzhankoy” lines in the course from December 18, 2009 to February 2, 2010. There have been investigated glaze-ice and rime depositions on the cables of high-voltage lines and towers. The coefficient of exceeding actual loads in comparison with the design ones at the moment of failure was determined. There was considered a cascade failure of the intermediate metal towers of the CP-25I type and the site of damage initiation was revealed. To specify the capability of a further operation of the survivor towers № 303 and 304 of the high-voltage (330kV) lines “Kakhovskaya — Dzhankoy” their technical state was estimated; a necessity of that estimation was caused by the consequences of the intermediate towers № 305-318 damage which occurred in the same anchor span. The article comprises the analysis of the operating capacity of the supply overhead power transmission lines of the Crimean power station of the NEC “Ukrenergo”. There are given organizational and technical arrangements not to allow any similar technological disturbance and to increase the high-voltage line reliability.
Keywords: overhead power transmission line, glaze-ice and rime depositions, tower technical state survey, failure, reliability.
A.V. Perel’muter, E.Z.Kriksunov, V.V. Yurchenko
Design of flange bolt connections according to the EuroCode and ukrainian codes: coordination and contradictions
Кiev National University of Civil Engineering and Architecture
Abstract. The purpose of the article is to show how the design of bolt connections of steel components given in the European and National Codes of design correlate and to find contradictions in them. A necessity of a such a comparison occurred because of an active import of the European metal structures into the Ukrainian building market. There has been developed and given a program of designing metal structure components implementing different design codes.
Keywords: metal structure components, bolt flange connections, bolt shear connections, design model, software implementation.
V.S. Zhivchenko, S.A. Frolova, V.D. Alexandrov
Influence of the technology of a daisy-chain blowdown of a structural steel melt to remove non-metallic inclusions
Donbas National Academy of Civil Engineering and Architecture
Abstract. There are given the results of theoretical and practical investigations of the processes of blowing down a liquid metal with a gas. When simulating the processes there was fixed that a decrease of the distance among gas bubbles results in the bifurcation of paths of motion due to the affect of a swirl of a previous bubble, and an increase of bubbles dimensions leads to their pulsation in the vertical plane up to their breaking into smaller ones. Besides, there was found out that the most maximum effect of nonmetallic inclusions removal is observed at a daisy-chain blow-down of a melt through porous seams of a bucket floor or through line-slot sections in a small-bubble regime. On the base of the simulation results there were plotted dependences of the refinement degree, numbers of bubbles and their behavior and the melt blow-down intensity. There are given the results obtained when implementing the technology of the daisy-chain blow-down of a metal in the small-bubble regime at the ferrous metallurgy enterprises.
Keywords: blow-down with an inert gas, blow-down intensity, refinement degree, small-bubble regime, daisy-chain blow-down, line-slot sections.
V.P. Gorbatenko, A.V. Lukin
Specifics of structural iron structure formation at the controlled rolling and thermal aftertreatment
Donetsk National Technical University
Abstract. The structure and properties of plate rolled high-strength structural steel of different composition were studied after the controlled rolling. There is shown that a decrease of temperature of the deformation completion leads to an increase of strength properties, an increase of the structure streaking degree being observed thereat. There is described a mechanism of the structure streaking formation at a low-temperature controlled rolling. It is shown that the reason of the structure streaking is “treatment liquation” — a specific chemical inhomogeneity formed in the process of rolling at the temperatures lower then the temperature recrystallized threshold. It has been found out that a dark streak pattern in steels after the controlled rolling can remain at further production modes. There has been studied the process of austenitizing steel with a ferrite-pearlitic streaking. It was determined that in heating up to 900°С austenite still has “treatment liquation” preserved which becomes apparent in the form of streaks of a higher etching, these streaks being located at the place of the previous perlitic streaks.
Keywords: high-strength structural steels, reliability, controlled rolling structure formation, dark streak pattern, homogeneity, mechanical properties, thermal treatment, austenitizing.
Ye.V. Horokhov, V.N. Vasylev, A.N. Alyokhin
The procedure of ice simulation onto antenna support bearing profiles in the climatic chamber
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article is devoted to the procedure of ice simulation onto antenna support bearing profiles in the climatic chamber of the DonNACEA. There was developed a test bench and mounting base to study real coatings of ice on angles of different cross-section at wind directions 450 and 900 to study icing factor 
2. To develop the test bench of ice coating imitation, the conditions were simulated in such a way that scale coefficients of wind velocity and direction, of drop diameter, of outdoor temperature and profile section which characterize the similarity conditions of the model and natural processes of deposition of cloud drops obtained by solving a mathematical problem were performed in the scale 1:1. So, to solve a targeted problem there was designed and created a climatic chamber in the DonNACEA. The procedure represented allows performing model ice-wind tests and then to determine carrying capacity, deformability, mechanical strength and antenna support natural frequency of oscillations and resonance under ice-wind effects with a specified coefficient 2.
Keywords: antenna support, icing, wind, climatic chamber, angle, procedure, testing , ice-wind effects, coefficient 2, test bench, test program, nozzles.
V.F. Mushchanov, M.P. Kashchenko, Yu.V. Sivikon’
Clarification of some peculiarities of the deflected mode of a membrane coating on the square design
Donbas National Academy of Civil Engineering and Architecture
Abstract. There is described a deflected mode of a membrane shell structure on the square design with the help of the non-finite elements method in the software program SCAD and in the approximated analytical design technique. The investigation of the deflected mode was carried out in the shell structure + profile complex regarding their integrated operation. Analysis of the deflected mode was done to find out an influence of meaningful factors on the critical force value in designing a compressed-bent profile on stability. There was carried out a numerical experiment to analyze an influence of dimensionless parameters on the deflected mode of a membrane coating and a “free” zone value.
Keywords: membrane coating, compressed-bent profile, deflected mode, stability, “free” zone.