Vol. 26, Number 2, 2020

Vadim Gubanov, Anton Tolstiakov
Modeling the Interaction of Chimneys with Wind Flow
Donbas National Academy of Civil Engineering and Architecture
Abstract. Modeling the physical process of air flow around a steel pipe barrel and determining its geometric dimensions and boundary conditions. Determination of the effect on the chimney of air flows that may vary depending on the superstructure, such as vibration dampers, windings, etc. The object of research is a steel, free-standing cylindrical chimney with a height of 30 m and a diameter of 1,5 m, without a lower cone and drawbars. By means of flow modeling according to the method given in the book
A. N. Birbraer, A. Yu. Roleder «Extreme impacts on structures» 2009, obtained a visual picture of the distribution of speed, pressure, and the resulting turbulence near the calculated surface. Certain wind loads applied to the pipe stem allowed us to identify the main features of the pipe’s aerodynamics as a poorly streamlined body and determine the values of drag. The numerical calculation was performed in the Mathcad 15.0 program. Visual modeling of the effect of air flow on the structure under study was performed using the Comsol Multiphysics 5.4 software package.
Keywords: chimneys, modeling, wind flow, wind load, Reynold’s number.

Andrey Mironov, Dmitro Belyy, Vladimir Anishсhenkov
The Stress-Strain State of a Steel-Reinforced Concrete Slab using a Profiled Sheet as Part of the Floor of a Building
Donbas National Academy of Civil Engineering and Architecture
Abstract. The paper presents the calculation methodology, modeling and assessment of the stress-strain state of a steel-reinforced concrete slab and using fixed formwork from a profiled sheet with a plan size of 2×0,5 m in the assembly and operation stages. The calculated moment of crack formation in the steel-reinforced concrete slab is determined, the possibility of resistance due to the adhesion forces of concrete with the sheet without the installation of additional stops and anchors is identified, the suitability of the structure under study for groups of limiting states is determined. The analysis of the results obtained in the PC «LIRA SAPR 2016». A theoretical range of permissible loads is revealed for which cracking does not occur. The diagram of the distribution of arising deformations along the height of the normal section of a steel-reinforced concrete slab is considered. Conclusions are made on the bearing and deformation capabilities of the investigated design.
Keywords: slab, profiled flooring, concrete mix, load, shear forces, anchoring, deformation.


Igor Romenskii, Andrey Mironov, Nonna Tarasenko, Egor Mescherin, Alexey Gladkikh
Constructions Runs Coverings in the Form Castellated Beam
Donbas National Academy of Civil Engineering and Architecture
Abstract. This article is devoted to the issue of the use of runs in the form of effective structural solutions for beams with a perforated wall. The paper presents an algorithm for calculating perforated wall beams obtained from rolling I-beams with a slope of the inner faces of the shelves for various snow regions and various coating designs. A typical series of runs in the form of beams with a perforated wall 12 meters long for various snow regions, depending on the maximum design load, is proposed. An analysis was also made of the effect of loads on the change in the height of the cross section and the consumption of steel of the girder structures in the form of beams with a perforated wall. The data obtained allow the selection of run sections in the form of effective beam structures depending on the load.
Keywords: run, I-beam, castellated steel beam, stress-strain state.

Evgeniy Gorokhov, Volodymyr Vasylev, Alexander Mushchanov, Alexander Volchkov
Experimental Study of the Influence of Node Joints of Structural Structures on the Stability of Central Compressed Rods
Donbas National Academy of Civil Engineering and Architecture
Abstract. The paper presents the results of experimental studies of the loss of stability of centrally compressed rods of the structural coating cell. Rod material – St2, flexibility l = 120. The prerequisites for the study were finite element modeling of both a single rod with actual fixing conditions [10], and rods as part of a structural coating cell on a 1:1 scale. The level of the calculated load on the experimental and on the numerical model was 30,525 tons. The analysis of numerical studies indicated the loss of stability of the rods in the elastic stage. Experimental studies have confirmed the loss of stability in the elastic stage, but have shown the development of local plastic deformations in the most stressed section of the bar. Based on the recorded results of experimental and numerical studies, it is proposed to introduce the value of the correction coefficient ke in relation to the results obtained using the regression dependence given in [10].
Keywords: centrally compressed rods, buckling, experimental research, LIRA-SAPR, modeling, stress-strain state.