Aleхandra Krysko
Calculation of the Intense Deformed State of Tank’s Wall Under the Action of the Hydrostatic Load in a Nonlinear Setting with Geometric Imperfections
Donbas National Academy of Civil Engineering and Architecture
Abstract. The work substantiates the necessity of taking into account the specificity of the hydrostatic load when calculating the wall of a tank with geometric imperfections. A step-by-step scheme for loading the tank wall with hydrostatic pressure has been developed, which makes it possible to perform a geometrically nonlinear elastic analysis with imperfections included geometry. The intense deformed state of an exploited tank with geometric imperfections under the action of a hydrostatic load was studied, which made it possible to reveal the tendency of the stress change as the tank was filled. The carried out research allows determining the maximum height of filling liquid in the deformed reservoir for its further safe operation.
Keywords: steel vertical cylindrical tank, hydrostatic load, the intense deformed state, the defects of geometrical form, geometrically nonlinear elastic analysis with imperfections included.
Volodymyr Mushchanov, Andrei Mironov, Alexander Kovalenko
Numerical Researches of Local Stability of Beam Webs of Component i-Section with Local Dimples-Bucklings in Span Structures of Bridge Constructions
Donbas National Academy of Civil Engineering and Architecture
Abstract. The aim of researches is an estimation of influence of characteristic geometrical imperfections on local and general stability of elements of bridge constructions as flange metallic beams with component section. An object of researches is a steel main beam of component i-section of middle span (Lmax = 11,4 m) for the three-span road-transport overpass executed on a cut beam scheme 8,6+11,4+8,6 m. Researches were conducted with the use of a program complex SCAD Office 11.5, during elastic work of material. A calculation scheme was the spatial system designed by finite elements as shells of rectangular and three-cornered configuration for the plane stress state. On results of calculation the forms of loss of stability and coefficients of supply of stability were determined, that allowed to estimate the value of influence of one or another imperfection on bearing strength of the examined beams. The results of researches can be used at the primary estimation of local stability of web of beams with the indicated imperfections.
Keywords: bridge building, beam cut scheme, beam with component i-section, defect, stress-deformed state, local stability, general stability, form of loss of stability, coefficient of supply of stability.
Volodymyr Mushchanov, Maxim Tcepliaev
Comparative Analysis of the Effectiveness of Constructive and Design Methods for Ensuring the Stability of the Walls of Vertical Cylindrical Tanks
Donbas National Academy of Civil Engineering and Architecture
Abstract. This article considers the normative documents of the USA, Europe and some CIS countries for comparison of calculation and design methods of vertical cylindrical tanks for oil and oil products. The need for such an analysis is caused by the widespread cases of local instability on the cylindrical walls of tanks. In addition to compare the calculation methods and design requirements, the article presents the results of analytical calculations for the stability of the reservoir wall in two design versions: with and without rings. According to the results of analytical calculations, stability stocks were determined, which give different norms. In addition, for each analyzed document unaccounted factors, which can lead to the loss of stability of the wall, are given. This gives us a direction for future research.
Keywords: vertical cylindrical tank, wind load, stress, finite element method, cylindrical shell, local imperfections.
Yevgen Gorokhov, Alexandr Mushchanov
Analysis of the influence of structural features of nodal connections on the load-carrying capacity of centrally compressed rods of structural coatings
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article presents the analysis of the stability of centrally compressed rods with initial geometric imperfections, performed with the help of volumetric finite element modeling of rods taking into account the design features of nodal connections. The analysis of 5 standard sizes of tubular elements in accordance with GOST 10704-91 «Electrically welded steel welded pipes» (in the range from 48.03.0 to 102.03.5 mm) in the software package of the family LIRA-CAD. The calculation is performed in a geometrically nonlinear setting in the elastic stage of the material. In the analysis of stability, the stability factors of stability are analyzed from the results of nonlinear calculation (ky, np) and in the direct analysis of stability (ky). Refined values of the critical force from the nonlinear calculation data (Ncr, NR) and from the stability analysis (Ncr, A) are presented. The obtained data were compared with the values of the critical force, determined from DBN V.2.6-198: 2014 «Steel structures» (Ncr, DBN) and Euler critical force
(Ncr, E). With the help of multiple linear regression, Microsoft Excel has established a generalized approximating relationship between the significant factors affecting the refined value of the critical force (Ncr).
Keywords: structural coverage, centrally compressed rod, stability, finite element method.