Serafim Fomenko a, Evgeniy Denisov b
Rational parameters of a «damper on the thread» for damping bending oscillations of rigid bus structures
a Donbas National Academy of Civil Engineering and Architecture, b Architectural and Design Office «Modus» Ltd
Abstract. The paper deals with the principle of dynamic damping of girder rigid bus structures of the outdoor switchgears. The special «damper on the thread» has been used to suppress of oscillations, which is placed inside the tubular bus conductor and «turns on» when the occurrence of cross sectional oscillations of the bus conductors. The effect of damping is achieved due to the transfer of vibrational energy bus to damper and the dissipation of energy due to dissipative material properties of the damper. The article presents numerical researches of the efficiency of the damper in its various parameters. The rational parameters of a «damper on the thread» are set. The experimental tests data of damping bending oscillations of cantilever tubular section beams with the application of a «damper on the thread» are given in the article.
Keywords: suppress of oscillations, damper on the thread, dynamic oscillation damper, damping, rigid bus.
Anna Ihno
The calculation system of the construction of the glass furnace bottom
Donbas National Academy of Civil Engineering and Architecture
Abstract. At present the design of piping glass furnaces is based on practical experience, and the selection of sections of the metal frame and furnace bottom are laid with a large margin, since operating elements of a skeleton in an environment of high temperatures. The task of this survey was to determine the temperature fields of the metal structure of the bottom of the furnace. To create a full frame design scheme of a glass furnace it was required another survey about the metal structures of the bottom of the furnace. The survey was conducted on a continuous glass melting furnace plant LLC «Stroysteklo-trading» in Constantinovka. Survey carried out joint connections of furnace bottom to the definition of the temperature of operation. As a result of the survey revealed the actual design of the bottom of a glass furnace and investigated the nodal connections. Defined operating temperature structure of the bottom, which is directly proportional to the temperature regime in the furnace unit. Indicators of temperature increase gradually in the cooking part and lower in the used part of the furnace.
Keywords: glass furnace, the bottom of the furnace, the arch of the furnace, frame, the main part, temperature indicators.
Volodymyr Mushchanov, Margarita Kashchenko, Arusyak Vardanyan
Refined design models for investigating the stability of the support contour membrane roof on the square and elliptical plans
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article deals with the problematic issues of investigating the stability of the reference circuit, which are regarded as common to membrane roofs on rectangular and elliptical plans and are a necessary step in the development of design solutions. Methodical approach for assessing the possibility of loss of stability of the support contour membrane roof has been developed. Criteria for deformation of objects-analogues have been determined, the numerical simulation of the buckling centrally and eccentrically compressed bars, as well as circular and elliptical rings, has been considered for specific example. Values of the calculated stresses for specific embodiments of the membrane roofs have been analyzed. The resulting solutions can specify and estimate the values of the critical force for the elements of the support contour membrane roofs on rectangular and elliptical plans.
Keywords: membrane roofs, compressed-bent support contour, loss of stability, deformation criteria, objects-analogues.
Alexandr Demidov
Revisting the pertinence of theory of little elasto-plastic strain when calculating shells in the process of inelastic behavior of material
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article is devoted to verification of competence of application of the before developed method on determination of the resiliently-plastic tensely-deformed state of shells of arbitrary form on the basis of theory of small resiliently-plastic deformations at linear approximations of decision of tasks the method of resilient decisions. In every progressive approximation at the decision of resilient task, the variation equalization of Lagranzha is used in moving of points of middle surface of shell in eventual differences. At the record of variation equalization of Lagranzha connection between tensions and deformations is presented in form of Hookers law, but with additional members, taking into account plastic deformations. Geometrical equa-lizations are accepted in the linear raising in form of Cauchy relations. Material is characterized by the proper diagram of tension of cylindrical standard, module of normal resiliency and Poisson ratio. Kinematics scope terms are satisfied exactly, and static, on the free of fixing edges of shell, is approximately. The task about the competence of application of method of resilient decisions for the unreserved cylindrical shell of permanent thickness, hardly jammed in circuitous direction and joint fastened in meridional direction with the large joint fastened opening at operating on it of the evenly distributed normal to the middle surface loading, is considered. It is confirmed by the construction of trajectory of deformation in three-dimensional subspace of the fivemeasured vector space of A. A. Il’yushina for the elements of shell being in the resiliently-plastic state. For this purpose the calculation of this shell is carried out at three values of loading, that allows to build the trajectory of deformation. Work is devoted to the up-to-date question of structural mechanics of shells at the action of loading at resiliently-plastic deformation at the active process of loading.
Keywords: barrel shell, variation and difference method, method of linear approximation, density of shear stress, plasticity function, strain path.
Volodymyr Mushchanov, Hanna Zubenko
Wind load definition on vertical cylindrical tank with membrane roof in the group
Donbas National Academy of Civil Engineering and Architecture
Abstract. This article describes a comparative analysis of the aerodynamic characteristics for VTDR of 10 thousand m3, and forecasting on the basis of the results of aerodynamic characteristics for vertical cylindrical tanks (VCT) with membrane roof in a group of numerical simulation method in the software package SolidWorks Flow Simulations, also a methodical approach, ensuring the correct display of physical process flow wind flow tank wall, has been suggested. For groups of 2 and 4 tanks on the basis of numerical simulations, improved values of the aerodynamic wind pressure coefficients for each of the tanks have been found out, these values provide further refine the assessment of the stress-strain state of the wall structure and the coating compared with normalized currently on approach DBN (State Building Norms) and Euro Cods.
Keywords: vertical cylindrical tank, numerical simulation, wind pressure, aerodynamic coefficient.