Yevgen Gorokhov, Volodymyr Vasylev, Andrii Alokhin
Engineering research of static behaviour of A0-60 aerial support on testing ground of Donbas National Academy of Civil Engineering and Architecture
Donbas National Academy of Civil Engineering and Architecture
Abstract. The paper has revealed the static testing results of the AO-60 aerial support under the effect of the glazed ice and wind attacks. The static tests have been carried out by four loading diagrams to bring out bearing capacity and deformability of the support (deflection determination by the second group of the limit states) on the testing ground of the Donbas National Academy of Civil Engineering and Architecture. The tests by the first three loading diagrams have been carries out to check the fundamental results of the traditional design techniques of the aerial structures under the effect of the glazed and wind attacks. Loading gathering on to the AO-60 aerial support has been done by DBN B. 1. 2-2:2006 «Loads and effects» [7]. The tests by the forth diagram have been 0.25 of the maximum wind action to one side, complete mass, equipment weight and glazed frost with a precise factor 2 having obtained by engineering research in a climate chamber of the Donbas National Academy of Civil Engineering and Architecture [5]. The static tests have enabled to determine the real activity (movement) of the aerial supports under the effect of the glazed and wind attacks.
Keywords: engineering research, aerial support, testing ground, static tests, glazed frost and wind attacks, movements, loading diagram, efforts, load, deflection.
Volodymyr Vasylev, Yuliya Dozorenko
Free strained dissolution of hot-rolled joists to t-beams of variable altitude for perforated beams
Donbas National Academy of Civil Engineering and Architecture
Abstract. The paper is concerned with the problems of engineering and application rationality of perforated wall beams. The typical joist internal stress diagram has been cited. Special attention has been given to the effect of heating on the internal stresses and their redistribution. The diagram having formed in the beam by means of preheating of the profile wall and its cut on the Z-shaped line and also the dissolution process of the hot-rolled joist by gas torches have been presented. The behaviour features of the finished structure and its internal stressed state have been detailed. The strength test of the perforated joists in the section moderated by holes on the maximum normal stress has been conducted. The paper is oriented on further investigation of the stressed state of the perforated beams, minimization opportunities of consumption of human labour and cost, bearing in mind their manufacturing procedures and techniques.
Keywords: hot-rolled joist, perforated profile, stressed and strained state, plastic strains of shortening, dissolution, Z-shaped cut, residual stress, free strained dissolution.
Anatoly Perelmuter
About one concept in the theory of constructions
SCAD Soft Сo
Abstract. Conditions of use of the known concept which specifies in economic feasibility of continuous growth of individual capacity of industrial targets are analyzed. In the theory of constructions, this concept has got the statement form about expediency of concentration of a material in the basic designs. This fact is illustrated by various examples where data about the expense of a steel on erection of designs of martin shops, blast furnaces and tanks are cited. However growth of individual capacity is not accompanied by the same growth of their reliability. Such is one of accident lessons on the Chernobyl atomic power station. The analysis considering restrictions which are defined by safety conditions is made, and is shown, that the mentioned concept has applicability border.
Keywords: the theory of constructions, safety, growth limit.
Igor Byelov, Vitalina Yurchenko
Resistance check of central struts composed of isolated thin-webbed cold roll-formed shapes with open cross section
Laboratory of Structural Testing
Kyiv National University of Civil Engineering and Architecture
Abstract. The extensive use of structures of domestic produced thin-webbed cold roll-formed shapes is delayed, first of all, because of imperfection of the normative base and the deficient domestic experience of economic and reliable designing of such type of structures. Therefore, the paper has adequately elucidated the problem of normative checking analysis of the thin-webbed cold roll-formed shapes resistance in accordance with the Sanitary Regulations II-23-81*, Civil Engineering Regulations 53-102-2004 and the first version project of the National Civil Engineering Regulations of Ukraine B.2.6. The paper gives consideration to determination of reduced dimensions of the cross section of the members of thin-walled cold roll-formed shapes for the cases when the slenderness ratio of the section members (flanges and/or a web) exceeds their limiting value.
Keywords: complete delivered light-gauge steel buildings, cold roll-formed shape, thin-webbed members, checking analysis of resistance, reduced sectional dimensions.
Yevgen Gorokhov, Volodymyr Vasylev, Sergiy Kuznetsov, Igor Garanzha, Eduard Lozinsky
Experimental aerodynamics of sections of polyhedral bent racks
Donbas National Academy of Civil Engineering and Architecture
Abstract. The paper represents the range of application of the structures based on polyhedral bent racks (PBR) both on the territory of Ukraine and abroad. The paper has undergone the aerodynamics analysis becoming the base of the technique development and also for conducting of the physical modelling and research of PBR model fragments in the meteorological wind tunnel of the Donbas National Academy of Civil Engineering and Architecture to determine the basic aerodynamic characteristics – the drag coefficient of the PBR structures with various number of sides, bearing in mind the weather factors of impact on the determination of the wind loads. The aerodynamics experimental techniques at the PBR model fragments have been described in the paper. The outcomes of the experiment (on the example of the hexahedral PBR model) have been presented and they have been compared with the normative values of the drag coefficient. As a result, the aerodynamics technique for the structures on the base of PBR has been revealed, the dependence between the Cx coefficient values and the wind flow direction, the impact of Reynolds number, the number of the structural bounds, the distribution of the wind flow velocity in a ground and boundary layer and the definitive drag coefficients Cx have been determined experimentally.
Keywords: polyhedral bent racks, engineering aerodynamics, wind tunnel tests, local factor, drag coefficient, meteorological wind tunnel, wind flow.
Yaroslav Nazim, Olexandr Leshchenko
The question of defining ice and wind loads on overhead power transmission lines in complex relief
Donbas National Academy of Civil Engineering and Architecture
Abstract. The paper deals with the definition of ice and wind loads for overhead power transmission lines in a complex terrain. The authors have used a comparative approach to the definition of climatic loads on overhead lines in mountainous terrain on the example of different techniques. As sources of information used data from the climatic zoning Regulations for Electrical (amended in 1965 and 2006). As well as used data closest weather stations in the 50-year period in order to clarify the microclimatic zonation. Analysis of climatological information led to the conclusion that the methodology of Regulations-2006 provides the most reliable design. However, the use of weather stations located in different orographic conditions, due to their weak correlation leads to a significant increase in the loads on the OPTL. Analysis of the topographical conditions of the location of weather stations and OPTL, together with the definition of conditions of formation of ice and wind effects can significantly reduce the load.
Keywords: overhead power transmission lines (OPTL), ice and wind loads, weather data, climatic zoning.