Volodymyr Vasylev, Andrey Mironov, Anatoliy Yugov, Аlexey Bondarev
The results of experimental and theoretical research efforts in the assembly hinge-core system using a control system
Donbas National Academy of Civil Engineering and Architecture
Abstract. Determination is made and a detailed theoretical analysis of the stress-strain state of the experimental metal hinge-rod system with a control system, considered as a flat statically indeterminate system with articulated units. The values of the theoretical assembly effort in this system are obtained by computing complex SCAD. When calculating the assembly effort took into account the different distribution of assembly errors. The scheme of a specialized experimental facility. Shows the experimental values of the assembly effort in the study design with a control system errors. Based on the results made a detailed comparison of the experimental values with the theoretical efforts assembly, assembly force determined by computing complex SCAD. The results and the methods of experimental studies can determine the assembly efforts not only in the flat hinge-rod system, but also in the spatial span.
Keywords: large-span steel structures, bar systems, errors assembly, installation impact, dimensional chain, the stress-strain state, control theory, finite element method, the experiment.
Volodymyr Kushchenko, Аlexander Nechitailo
Local strength design of resting joints of the shaft frame-type sloping headgear guide pulleys
Donbas National Academy of Civil Engineering and Architecture
Abstract. In the paper the results of the theoretical and experimental research of the mode of deformation of the sub-pulley structures of the shaft frame-type sloping headgears have been given, on the basis of these results the strength of the guide pulley resting joints has been analyzed. Engineering procedure of checking strength by the local normal stresses and by the reduced stresses depending on the design and technological factors has been suggested. The guidelines on the intelligent design of sub-pulley structures of the shaft frame-type sloping headgears have been developed; these guidelines contribute to the improvement of the engineering procedures of designing steel structures of the shaft frame-type sloping headgears.
Keywords: shaft frame-type sloping headgear, sub-pulley structures, sub-pulley resting joint, strength analysis, mode of deformation, local stresses.
Myron Gogol
Techniques and algorithms rational design combined metal structures
National University «Lviv Politechnique»
Abstract. This article describes how to increase the economic efficiency of the combined metal structures. It is shown that this is necessary to give the design process of scientific support and minimize element of subjectivity in choosing the design decisions. Technical and economic efficiency of steel structures can be provided, on the one hand, the development and introduction of advanced methods of calculation and design of new schemes, on the other – a regular analysis of design methods. Emphasized that the most efficient method of regulation is calculated – in the design process, and the problem of design of structures, including combined, should initially posed as a problem of their rational design. The generalized mathematical model for calculating the combined structures based on energy approach taking into account the strain state of the beam stiffness. Shows the calculation are: first, based on the method of decomposition of the system, the system is divided into two subsystems – the main and auxiliary. Further, using the synthesis system calculated its stress-strain state. An algorithm for calculating and rational method of designing a combined structure.
Keywords: model, method, combined structures, equi-stress, rational desing, control, efficiency.
Igor Garanzha
About approaches to the calculation of composite tubes in Ukraine and abroad
Donbas National Academy of Civil Engineering and Architecture
Abstract. In a paper are determinated an area of using composite tubes as structures. Considered four existing analytical methods for determination a load capacity of composite tubes with circular cross-section under axial compression are using in Ukraine and abroad. Analyzed approaches to the questions of a limit compression load (load capacity) calculation are able to withstand a composite element. Highlighted the fundamental features and similarities of discussed methods, and also their shortcomings affecting to the accuracy of the strength and stability computing results for composite tubes. On the particular example performed a results comparison of determining the load capacity by the four methods and determinated a difference which is varies (in relative units) within 1,08…1.38.
Keywords: composite tubes, analytical methods of calculation, joint work, axial compression, load capacity, strength and stability of structures, reduced flexibility, contact between materials.
Yaroslav Nazim а, Anatolii Kvytsynskyi b
About the need to improve reliability of certain sections of intersystem power transmission lines
а Donbas National Academy of Civil Engineering and Architecture
а Separate Division «Scientific-Technical Center of Power Industry» of State Enterprise «National Power Company «UKRENERGO»
Abstract. Defining role in the design and operation of support structures of intersystem power transmission lines plays the problem of reliability of structural components under the influence of climatic loads during the entire period of operation. Electrical Installations Code (PUE) establish four classes of reliability depending on the voltage power lines and thus regulate the determination of loads in the calculation of the structural elements of the HV on criteria to ensure trouble-free operation of the mechanical part of the HV under the influence of external factors for the settlement period of operation of the line. However, the massive failures of the first decade of XXI century in power networks of Ukraine have shown a lack of reliability of certain sections of overhead power lines that were built in sixties-seventies last century, with elevated icing and wind impacts. On the example of overhead power transmission lines 330 kV there was substantiated the necessity to improve the reliability of lines’ sections, which provide work between systems. It have been formulated in which cases the experience of operation of electric networks it is allowed to make icing and wind loads on overhead lines at one class higher reliability.
Keywords: overhead power transmission lines (OPTL), reliability, trouble-free operation, icing and wind loads.
Volodymyr Semko, Olena Voskobiinyk, Alexandra Skyba, Kateryna Shumeiko, Dmytro Prokhorenko
Complex experimental investigation into light steel and steel-concrete composite structures made of Z-shaped sections under compound stress
Poltava National Technical Yu. Kondratyuk University
Abstract. The paper is devoted to the analysis of peculiarities of structural behavior of light steel and composite structures under compound stress, including joints and influence of bending with torsion. The results of an experimental test cycle on such structural elements made of Z-shaped elements are derived. Structural behavior character of beams made of bolted Z-shaped elements with onlays is determined on the basis of a series of experimental research. The efficiency of using light steel thin-walled structures with light insulating concrete (light composite structures) for the purpose of local stability enhancement of thin-walled steel profiles under complex deformations – bending with torsion, – has been experimentally corroborated. Complex sections anchorage methods have been proposed.
Keywords: lightweight steel structures, thin-walled cold-formed steel structural profiles, Z-shape sections, sleeved bolted joints,lightweightinsulating concrete, composite structures, anchoring, complex types of deformation, bending with torsion.