V. F. Mushchanov, J. J Kalmikov, I. V. Romensky, D. I. Romensky
Research of the bearing capacity and development of a new design decision of the support point of the cyllindrical silo funnel in resonstrcution
The Donbas National Academy of Civil Engineering and Architecture
Abstract. The article is devoted to the consideration of the basic questions of increasing the reliability of the attachment point of a steel funnel to a reinforced concrete wall of a silo for storing coal. There is considered a constructive decision of the existing attachment point with the help of plate components which are embedded in concrete on the one end and the opposite ends are welded on the funnel. There was carried the finite element analysis of the existing constructive decision of the attachment point in the software complexes “Lira-Windows” and “SCAD”. In specifying efforts in the wall and in the components of the funnel hanger there was taken into account a joint operation of the silo and the adjoining structures of the adjacent silos both for the spatial elastic system and a nonlinear work of concrete. It was found out that in the concrete part of the funnel hanger node tensile stresses in concrete in the place of embedding band components are 2…2.5 times higher than the design resistance of concrete tension. The formation of a plane of break is significant here, but at a low reinforcement and damages in concrete it can cause the node failure. There is suggested a constructive decision of the conjunction node of the funnel and a silo wall which means an arrangement of the internal support casing made of a monolithic reinforced concrete with a further installation of support metal structures which comprise band components of the funnel hanger. For a horizontal component of the forces in the funnel hanger elements to be perceived, the support metal structures are attached to the structure wall. There is considered an influence of the form of the hanger components on the size and character of the distribution of stresses across the profile. The numerical calculations for a suggested funnel attachment scheme show a sufficient bearing capacity and assurance of conditions for a normal operation of the support node.
Keywords: silo, steel funnel, attachment point, analytical and numerical design methods.
V. N. Kushchenko
Shaft headgears on the character of dynamic loads of lifting cable tension
Donbas National Academy of Civil Engineering and Architecture
Abstract. There is considered an influence of operating features of mine winders on dynamic loads of lifting cable tension of shaft headgear stay legs. There were analyzed the conditions which cause losses of shaft headgear dynamic stability, design constraints aimed at the prevention of resonant phenomena were specified. On the base of the analysis of the data of the dynamic test of shaft headgears there was found out that maximum efforts in the lifting cables occur at the beginning of lifting a loaded vessel. The following should be considered as a design situation for specifying loads of lifting cable tension: a) for cage hoists – taking a loaded cage off the load mechanism; b) for skip hoists – a hoist engine accelerated motion. For design situations there are found out dynamic factors and there are given the formulas for determining rated forces in lifting cables which take into account the dynamic character of loads. There are given features of the dynamic stress cycles which are necessary for controlling fatigue strength of shaft headgear steel structures.
Keywords: shaft headgears, operating features, dynamic loads, dynamic stability, fatigue strength.
Ye. V. Shevchenko, V. A. Glukhov, A. V. Tanasoglo
Study of a mode of deformation of a double-circuit corner dead-end support vl 330 kv using different software packages
Donbas National Academy of Civil Engineering and Architecture
Abstract. There is analyzed a mode of deformation of a corner dead-end support of overhead power transmission lines (OPTL) which is considered as a spatial multiple indeterminate open system with flexible joints. There is given a design procedure and design data of a plane spatial pattern support in the software package “SCAD” and in the software packages”USL” and “MISI1” developed in the Donbas National Academy of Civil Engineering and Architecture. An attention is given to the basic problems which can occur in setting initial parameters and in constructing design models for such structures. There are considered a number of problems connected with a refined specification of internal longitudinal stresses in the components of an OPTL structure. In designing there is analyzed a joint operation of the lattice components of a support spatial pattern model, an inclusion of stiffening diaphragms and diagonal element members in the operation on al four faces is taken into account. On the base of design and extension of the results there was thoroughly compared the internal forces obtained and the ones specified in the components of a pattern OPTL support on the similar values of loads.
Keywords: overhead power transmission line, plane model, spatial model, metal tower, design loads, stiffening diaphragm.
Ye. V. Gorokhov, V. N.Vasylev, A. M. Alyokhin, A. A. Yagmur
Analysis of the constructive form of the radio-relay communication antenna supports
Donbas National Academy of Civil Engineering and Architecture
Abstract. There is analyzed a constructive form of the radio-relay communication antenna supports. There are considered the problems connected with the design of antenna supports – towers and masts, and there are also analyzed the groups of tower supports by a constructive decision of verges, by the type of the materials applied, by the requirements for a degree of reliability and durability and service performance, by the place of installation, by the quantity of faces, by transportability, by the lattice type, by optimization of sizes and by the section of column components. On the base of the analysis of the existing methods of designing the tower-like support structures there was developed a conventional set of optimal antenna supports. There are given masses of type and optimal supports non-registering the weight of stairs and operating platforms for the sake of metal saving. There are analyzed the measures aimed at the decrease of cost and material consumption for supports, acceleration of time-frame of starting the object up at a full requirements compliance.
Keywords: antenna support, towers, masts, lattice and solid supports, shapes, tubular and angled section, faces, lattice, optimization, conventional and optimal sets.
V. N. Vasylev, I. M. Garanzha
Methods of the experimental investigation of the many-sided bent bodies operation in the supporting zone of overhead power transmission towers
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article aims at the comparative analysis of the theoretical and experimental investigations of a useful operation of many-sided bent bodies in the structure supporting zone. It focuses on the aspects of the world experience of applying structures based on many-sided bent bodies (MSBB), a wide application of these structures in different countries of the world being noted. There is considered a suitability of using the finite elements method implemented in the up-to-date design software packages in theoretical studies as well as the algorithm and specifics of the MSBB design model formation. There is described a principle of carrying out static experimental investigations of the MSBB model with the help of the specially made experimental unit. There are given the numerical results of the bodies investigation and the main conclusions on the work performed.
Keywords: many-sided bent bodies, constructive form, mode of deformation, finite elements method, static certified tests, theoretical and experimental investigations, tensometry, experimental unit.
Ya. V. Nazim, A. A. Leshchenko, V. V. Kostin
A comparative analysis of the approaches to the determination of climatic loads on the high-voltage lines illustrated by the crimean power plant
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article is devoted to the problem of power supply reliability on the Crimean peninsula because of the scale failure on December 18-19, 2009 which happened simultaneously on two overhead power transmission lines on the territory of the Perekop isthmus. The board of the failure inquiry still works; its conclusions are tentative for the present. In the article there are considered the main design data by the overhead power transmission lines, the analysis of the topographical conditions of the area and the meteorological situation in time of the failure was carried out. The authors applied a comparative approach to the determination of the normative climatic loads on overhead power transmission lines by the example of four methods, the Rules of electricity generating plant arrangement (in two editions, -1965 and 2006), the data of the climatic zoning and the data of the nearest weather stations for the observation period of 50 years being used as the sources of information to specify the micro-climatic zoning. There was performed a comparison of the specific loads on the overhead power transmission lines by the “The Rules…-1965” and “The Rules…-2006” for the corresponding design conditions with the actual loads at the failure, as well as a comparison of the cable loads on the overhead power transmission tower of 330 kV. Analysis of the climatological data made it possible to conclude that the methods of “The Rules…-2006” provide a larger reliability of structures. Nevertheless, in the course of elemental meteorological phenomena, loads can turn out to be larger than the basic ones. Some additional means should be applied to the parts of the electrical power system of Ukraine to prevent emergency situations.
Keywords: overhead power transmission lines, meteorological situation, weather data, geo-statistical methods, climatic and micro-climatic zoning, reliability.