L.V. Endzhievskiy, A.A. Yurchenko
Analysis of the numerical and experimental results of the stressed and deformed state of the closed section beam with perforated walls to withstand the free torsion with bending
The Siberian Federal University
Abstract. This article concerns the results of the experimental research of the close section steel beam with perforated walls under the free torsion impact with a curve. The comparison of the gotten experimental data and the results of the analytical numerical calculation with the method of the finite elements has been done.
Keywords: steel beam with perforated walls, free torsion impact with a curve, experimental, numerical research.
A.M. Alyokhin
Analysis oF finding equalities of scale coefficients for the glased frost imitation in the climatic chamber of DSACA
Donbas National Academy of Civil Engineering and Architecture
Abstract. In article the analysis of the third equation of the main correlations system [3] containing three coefficients of scaling for the glased frost imitation in the climatic chamber of DSACA has been made, as well as parametric system of the equations has been represented. This dependency differs from two previous by linking the values Кd, Кn, Kсв characterizing water flow. There has been made the evident dependency analisis of the scale coefficient for water density Krв from amount of the molecules in water Kn. The Particular derived functions g1(ДKсв,ДКn) leveled zero have been resolved, which, first, represent the straight lines equations where the tops of the ellipse are placed, but secondly, from system of the got equations centres of the ellipse ДКсв=0,6 and ДКn=0,6. Have been found while solving given problems it is necessary to know possible change of scale coefficients to find the necessary soltion version. So in the first semisystem it was suposed limited coefficients Кв<1 and Кн<1, but in the second system known as Кф and independent Кd.
Keywords: scale coefficients, system of equalizations, climatic chamber of DSACA, experiment, nature, model, gololed, blast, the system of co-ordinates, hyperbola, is direct, curve, the row Teylor.
V.N. Kushchenko
The dynamic characteristics influence of constructions oblique head frames on the parameters of the special loads because of lifting rope break
Donbas National Academy of Civil Engineering and Architecture
Abstract. In the article there are given the results of theoretical research of dynamic characteristics influence of head frames constructions on the special load because of lift parameters rope break. On the basis of mathematical design of dynamic interaction of head frame constructions with a lift machine while rising vessel gamming, the degree of forces influence of buildings mass on the size of main vector load has been set. For large lift machines, and extreme values of emergence load the dynamics coefficient is 1,05-1,1. For the lift mine settings equipped with small lift machines, the case, when the lift rope break is in possible, the coefficient of dynamics is 1.2-1.3. While designing of head frames it is necessary to take into the consideration the dynamic nature of lift rope loads. Especially the significant influence of forces inertia on the stressed deformed state of mine head frames constructions with placing of directive sheaves on the same level for oscillation of torsion forms in this case the dynamic coefficient are 1.3 – 1.6.
Keywords:head frame, loadings of emergencies, calculation of build constructions, coefficients of dynamic quality.
I.V. Romensky, I.V. Rusakova
Stabilization of sagging membrane coverings, working in the vertical cylindrical tanks composition
Donbas National Academy of Civil Engineering and ArchitectureSLR “Resurs- Engineering”
Abstract. The main questions of increasing the efficiency of vertical cylindrical tanks, by means of applying covers in the form of sagging membrane casings have been considered in the article. The application of such constructive decisions provides the mass reducing comparing with traditional decisions in the form of cupola coverings. A high deformation of membrane coverings concerns its fault. The essential load for membrane coverings working in the composition is the pressure redundant of tanks. For prevent possibility of the phenomenon so called inverse exhaust to apply measures of stabilization of the covering construction. It is proposed to use the reinforced concrete as a stabilized device. The mass of reinforced concrete element is selected out of compensation condition of the redundant pressure. The method of determination the optimum thickness of membrane casing has been proposed. Principles of non-linear mathematical programming, are used based on the penal functions method. The optimisational problem solution with using has been fulfilled the polyhedrondeorming method. For standard tanks with volume of 10…50 thousand cubic meters (according to diameter of 28,5…60,7meters) optimum parameters of membrane coverings have been determined. With the covering mass including additional loads from the stabizing element has been determined. Adducing the economical efficiency of proposed version of stabilized membrane covering in comparison with the standard decision.
Keywords: vertical cylindrical tank, membrane covering, stabilization, optimum projecting.
B. Dervinis, A. Kvedaras
Finite element method investigation of critical shear stresses of the web of steel beams
Vilnius Gediminas Engineering University
Abstract. On the basis of generalization of the results of mathematical modeling of the dynamic behaviour of the mechanical system «head-frame structures – a winder» a specification of spThe beams of 12 m long, web thickness is from 6 mm to 12 mm and web depth from 500 mm to 1000 mm, are analysed in this paper. The perforation diameter is selected from half of the web depth to the total web depth 100 mm minus. The cross-section area of two flanges was selected equal to the cross-sectional area of the web. The flanges thickness is equal two times the web thickness. Given beams have been loaded equally as for distributed load the upper flanges deformation are restrained out of plane. The general purpose of this work is to settle the critical shear stresses in the web wall and in this case it would lost the local stability. Calculations have been done using analytical formular and finite elements methods. Calculation results are represented compared with each other and are shown as charts.
Keywords: perforated steel beam, perforation, perforation form, finite element method, diameter of perforation, web-post buckling, critical shear stresses.
D.O. Bannikov
Determination of lateral pressure coefficient for friable material in closed vessel
Vilnius Gediminas Engineering University
Abstract. The author’s theoretical model for determination of lateral pressure coefficient of friable ma-terial on the closed vessel walls is diven in this article. The model represents 3-d space dis-crete system, which permits to take into account the most significant peculiarities of internal structure of the friable material. The distinction of the existent models from the other models has been shown. By means of the worked out model the author has obtained for calculation of the lateral pres-sure coefficient in a closed vessel. It was shown, that the coefficient depends on not only a row of physical and mechanical characteristics of the friable material, but also on the geomet-rical parameters of the vessel. Hypothesis made by the author as for the changing of the structure of friable material during its movement in the closed vessel allowed to obtain the special theoretical expression for the lateral pressure coefficient in the moment of discharge beginning. Its value is higher than for the analogous coefficient for the static state of material.
Keywords: friable material, capacity, pressure of friable material.