Lazniuk Mykhailo a, Ievzerov Isaak b, Маrtyniuk Oleksandr a
Influence of initial imperfections upon the operation of beams with a corrugated wall
a PEM Ukraine Ltd., Zeman Group
b Lira Soft Ltd.
Abstract. In the article problems of designing and manufacturing of steel structures of I sections with a thin corrugated wall are discussed. By means of a method of final elements influence of initial imperfections, such, as local curvature and a deviation of parameters of corrugating, on stability of the thin corrugated walls of bent elements has been investigated. Models have been designed with the deformed scheme taking into account not elastic operation of steel. The basic theoretical positions realized in the personal computer LIRA of a method of problem solving in geometrically and physically nonlinear statement by means of FEM are resulted. The theoretical data is confirmed by results of natural tests. The received results have been used when working out specifications of manufacturing of welded double tee with a corrugated wall.
Keywords: a beam with a corrugated wall, a method of final elements, stability, initial imperfections.
Kushchenko Volodymyr, Nechitailo Alexander
The analysis of the intense-deformed condition of the basic bearing elements of frame mowing mine headgears
Donbas National Academy of Civil Engineering and Architecture
Abstract. The numerical analysis of the intense-deformed condition of the basic bearing elements of a typical frame mowing mine headgear is made. The analysis has been made of two finite element for the design models realized in program complexes SCAD and LIRA in the form of rod and lamellar approximation of elements. For rod settlement model the elastic-plastic analysis is made. As a result of calculations parameters of the intense-deformed condition, spectra of own frequencies of fluctuations, factors of a stock of system stability, as elastic system are received. As a result of comparison of the received results a number of constructive elements of the headgear for which calculation under the settlement scheme in the form of rod approximation gives a considerable error is established. Recommendations for the design of frame mowing headgears with use of the settlement models consisting of cores and plates are presented.
Keywords: mine frame mowing headgear; the settlement scheme; computer modeling; elastic plastic analysis; intense-deformed condition; operating ratios on pressure; factors of a stock of stability of a construction; a spectrum of own frequencies.
Golodnov Oleksandr, Ivanov Anatoliy, Psyuk Victor
Simulation of stress-strain state of steel structures due to the results of the survey
Donbas State Technical University
Abstract. The feasibility of using an integrated method for estimating the stress-strain state of operated steel structures using methods of mathematical modeling is given. The method has been widely tested in matters relating to the technical condition of construction steel bins and extending their operation. The possibility of using the method for evaluating stress-strain state and the project of strengthening of structures is proved.
Keywords: steel structures, inspection, deformation, modeling.
Gubanov Vadim, Golikov Alexandr, Kulchitskiy Artem
Effect of local concavity upon bearing shell of high buildings
Donbas National Academy of Civil Engineering and Architecture
Abstract. This article describes one of the types of geometric deviations – concavity. Also the parameters that characterize it are defined. In addition, the results of numerical studies of the effect on the local concavity of the stress-strain state of shells of high buildings. The field of distribution of ring and meridian stresses in the investigated area is shown. The zones of influence on the concavity of the bearing shell of high buildings. It is also determined by carrying capacity of the barrel sections of high-rise structures with different geometries and different parameters of the concavity of the investigated membranes. The data obtained have been used to explore the dependence of reduction of the carrying capacity of the concave size, diameter and thickness of shells of high buildings.
Keywords: shell, concave, bearing capacity, the zone of influence.
Semko Alexsander, Voskobiinyk Olena, Gasenko Anton, Beskrovna Zhanna
Reliability of steel pipes at a random rate of corrosion
Poltava National Technical University named after Yuri Kondratyuk
Abstract. This article examines the reliability of steel pipes at a random rate of corrosion. A functional exponent relationship of mathematical models of corrosion has been used. It allows to assess the reliability of the element in terms of uniform corrosion under normal law of distribution of the random variable of the initial rate of corrosion. Using this model a diagram of change of the level of reliability during the time for the pipeline diameter of 820, 1 020 and 1 220 mm with a wall thickness of 8 mm is done. The dependence obtained showed that the smaller diameter pipes retain higher levels of reliability than with a large diameter pipelines for over 50 years of operation.
Keywords: steel pipe, corrosion damage, the reliability.
Peleshko Ivan, Baluk Igor
Optimal design of reconstruction overground beam overpass pipelines
National University «Lviv Politechnique»
Abstract. Reconstruction of the overground beam overpass pipelines across river Stry in Lviv region with regard by soil properties and changing its design schema as a result of building-assembly works is optimally designed. The numerical investigations of influence the soil properties and changing design schema of overpass on the stress-strain state of optimal structure are done.
Keywords: beam overpass pipelines, reconstruction, bar system, optimal design.
Nazim Yaroslav
Researches torsional rigidity of wires for electricity transmission air-lines
Donbas National Academy of Civil Engineering and Architecture
Abstract. In article the questions concerning researches of torsional rigidity of wires of air-lines of electricity transmission (ET) in laboratory of tests of building strictures and constructions of DonNACEA are considered. To achieve the purpose of researches new types of wires applied in world practice for ET are studied, the stand for rigidity studying on torsion of wires is developed and designed; experimental researches and their analysis are made. It is confirmed that rigidity on torsion of the sector condensed and compact wires (AAAC) above torsion rigidity of traditional steel alluminium wires (ACSR) even under condition of comparison on close values of diameter of a wire. Under condition of comparison of wires on equal current loading, given priority of modern types of wires considerably increases. Results of work are necessary for the further researches concerning studying of influence of wires twisting on icing, and working out the actions for the purpose of maintenance of trouble-free operation of ET at icing-wind influences.
Keywords: electricity transmission air-lines, a wire, rigidity on torsion, experimental researches.