Volodymyr Mushchanov, Iurii Priadko
Total algorithm of safety index of overhanging coating formed by rigid threads of through section
Donbas National Academy of Civil Engineering and Architecture
Abstract.The design algorithm of spatial pivotal coating with a cut in the elliptic setting formed by the system of rigid threads of through section based on determination of a numerical safety index of a designed structure has been described. The proposed algorithm provides the sequence of solution of problem series: determination rational geometric parameters of a structure; obtaining of appropriate rigidity characteristics of basic bearing elements; determination of a track of elements destruction for typical coating diagram with the following evaluation of stressed and strained state of an object; determination of numerical safety indices of a structure (determination of the lower and upper safety limits).
Keywords: spatial and pivotal overhanging cover, curve and rigid threads, safety indices, stressed and strained state (SSS), snow loads.
Volodymyr Kushchenko, Alexander Nechitailo
Analysis of the resistance to fatigue of shaft frame-type sloping headgear structures
Donbas National Academy of Civil Engineering and Architecture
Abstract. There are the results of the analysis of resistance to fatigue of shaft frame-type sloping headgear with multiple-hoist as in the joints guide pulley resting on the under pulley constructions in the article. The analysis was done by the design model consisting of plane and solid finite elements and which was realized in the program «Ansys Workbrench 14.0». Due to the numerical results in the top and bottom sub-pulley frames semi-hipped system headgear was detected the characteristic areas of variable stresses. Was done the analysis of specific areas under the influence dynamic loads, where were identified the characteristics of dynamic stress cycles. Referring to the characteristics of cycles were tested resistance to fatigue by three methods: SNiPII-23-81* (§ 9.2*), DBN V.2.6-163 (§ 1.11.2) and EN1993-1-9-2009 (§ 8). In whole, the results obtained are the base to improve the engineering procedures of designing steel structures of shaft sloping headgear considering the dynamic loads.
Keywords: the shaft sloping headgear, joint of a guide pulley resting, the local stresses, the fatigue stress, the characteristics of stresses cycle, the resistance to fatigue.
Vitalina Yurchenko
The shear resistance models of steel memberstaking into account the web buckling
Belarusian National Technical University
Abstract.This paper proposes analytic dependences for evaluation of elastic critical buckling loads of thin-walled bars of С section subjected to central compression. These analytic dependences have been developed for both local and distortional buckling cases of thin-walled bar. Critical loads have been calculated using shell finite element models of thin-walled bars of C section performing linear buckling analysis as for elastic system. Derived analytic dependences should be used as a component of engineering calculation technique for structures from thin-walled cold-formed profiles in order to take into account the local and distortional buckling effects at the post-buckling stage of the structural behavior.
Keywords: thin-walled bars, cold-formed profiles, critical force, linear buckling analysis, linear buckling, local buckling, distortional buckling, post-buckling behavior, finite element analysis.
Vadim Gubanov, Artem Kulchytskyy
The selection of calculated scheme for self-supported chimney numerical calculus
Donbas National Academy of Civil Engineering and Architecture
Abstract. It was considered the different cases of self-supported chimney calculated scheme modelling, that is stalky scheme in the form of the cantilever bar of uniform cross section; calculated scheme in the form of structural shell, modelled in the ANSYS Workbench 14.0 software solution; calculated scheme in the form of structural shell factored in substructure modelled in the ANSYS Workbench 14.0 software solution; calculated scheme in the form of unstructural cylindrical shell with geometrical deviation in the form of dimple. The received values of equivalent strain (von Mises’s strain – σeq) were compared with the main strains (σx), defined analytically for cantilever shell with equivalent strains (σeq) in the scheme with dimple for the structural shell in the ANSYS. The comparing approved the 15 % deviation strains for structural shell’s and the 65 % deviation fort the shell with dimple.
Keywords: chimney, calculated scheme, dimple, numerical methods, ground, equivalent tension, local tension, cylindrical shell.
Volodymyr Kushchenko, Miroslav Hubarev
Refinement of a dynamic factor of dead-end support of optl 110 kv for action of the pulse component of wind loading
Donbas National Academy of Civil Engineering and Architecture
Abstract.On the basis of the given aprioristic sources the analysis of the reasons of troubles of building designs of conveyor passageways is made. It is established that in the conditions of long operation troubles of conveyor passageways with superstructures executed of trusses are most often observed. As a rule, troubles occur owing to destruction of elements of a connecting lattice near to basic knots, and also owing to destruction of assembly joints of bottom flanges of trusses of superstructures. Destruction of central welded joints is caused by influence of following factors: local impact sredne- and strongly-corrosive corrosion environments; dynamic character of technological and emergency loadings; the unsuccessful constructive form of designs of superstructures. Destruction of elements of a connecting lattice of superstructures results from a local corrosive attack near to floorings in the conditions of strongly corrosive corrosion environment which is formed owing to a hydrowashing down of a coal dust and a prorash.
Keywords: troubles of building designs, conveyor passageways, operation factors, the reasons of troubles.