Vadim Yu. Alpatov, Igor S. Kholopov
About application of model of the hinge for welded unit of the beam, executed by two vertical seams
Samara State University of Architecture and Civil Engineering
Abstract. There are analyzed certain solutions of a I-beam and column assembly connection. There are considered certain assemblies of commercial and standard metal structures simulating a rigid and hinged connection. The basic features of an assembly belonging to the hinged or rigid type of connection depending on their design features are sorted out. There is presented a structure of weld assembly of a beam and column connection which differs from standard solutions. For this assembly its mode of deformation was studied. Correspondence of the assembly force work to the hinged designed model was analyzed. There are given the results of a non-linear machine computation of the assembly with the use of a specialized computation complex. Strength of the elements comprising the assembly connection at their task geometry and desired conditions of their loading is estimated. The level of reduced stresses corresponding to the yielding flow phenomenon in a material is taken as a criterion of strength exhaustion by an assembly element.
Keywords: standard solutions, series, assembly conjunction, steel, yielding flow, numerical researches, nonlinear computation, stresses, carrying capacity, Mises.
T. V. Marchenko, D. O. Bannikov
A comperative analysis of collapse forms of thin-walled bar elements
Dnepropetrovsk National University of Railway Transport named after academician V. Lazaryan
Abstract. There is presented a comparative analysis of collapse forms of thin-walled bar elements which are the base of the technology of light steel thin-walled structures (LSTWS). In particular, there was determined a critical load of centrally fixed thin-walled columns; different methods of computation were used, namely, analytical ones based on L. Ailer and V.Z. Vlasov’s theories; numerical ones based on FEM with the use of design and computer system SCAD for Windows; and according to the operating norms. The results obtained with the use of each method differ which can be explained by different approaches to the solution of the task of stability.
Keywords: collapse, LSTWS, ultimate strength, thin-walled bar FEM.
Ivan D. Peleshkoa, Myhajlo M. Palchikb, Vitalina V. Yurchenkoс, Mykyta А. Bylyaev c
Optimum design of steel frames for technical sulphur storehouse
a National University «Lvivska Politechnika»,
b OJSC «V. Shimanovsky Ukrainian Research and Design Institute of Steel Constructions»,
c Кyiv National University of Civil Engineering and Architecture
Abstract. This paper presents a problem statement and results of parametric optimization task of steel frames with lattice tube structural members for storehouse of technical sulphur. Parameters of geometrical scheme as well as cross-sectional sizes of frame structural members were considered as design variables. A structure weight and budget were accepted as optimization criteria. Technological constraints according to project statement, constraints which described verification conditions at the ultimate and serviceability limit states according to building standards and regulations as well as detailing conditions for tube structural joints were taken into account in the mathematical model. Parametric optimization task was solved using the software OptCAD (www.optcad.com) based on the gradient searching methodology. Optimum designs of steel frames obtained provide a significant reduction of the structure weight and budget.
Keywords: parametric optimization, steel frames, steel framework, gradient method, software.
A. M. Yugov a, V. I. Moskalenko b, A. V. Ihno a, A. M. Mironov a
Study of the VAT parametrs of a glass-melting tank furnace metallic framework under elavated temperature
a Donbas National Academy of Civil Engineering and Architecture, b «Prombudremont» Ltd
Abstract. There is grounded a necessity of monitoring the VAT of a glass-melting tank furnace metallic framework, the furnace structural concept is described, and its design model is given. There are given static design principles of a plane frame, methods of collecting loads on the metallic framework of the glass-melting tank furnace framework and methods of determining additional loads as a function of temperature are described. A space design model of the glass-melting furnace has been made. A design and estimation of strain in the framework were made with the help of the finite-element method (FEM). There were drawn conclusions to substantiate the fact of a considerable influence of temperature loads on the furnace metallic framework and a necessity of a further testing of a useful output of the glass-melting tank furnace framework by means of pilot studies.
Keywords: glass-melting furnace, temperature, furnace lining, metallic structures.
R. Wolchuk
Orthotropic decks — past developments and future outlook
Consulting Engineer, 921 Bergen Av., Jersey City
Abstract. Steel orthotropic decks, first introduced in the 1950s in Germany, are now used in bridges world wide. Their light weight and structural efficiency made possible long span bridges with span lengths that were previously considered unthinkable. Problems of fatigue and safety against cracking are discussed. Cracking at orthotropic deck welds are caused mainly by fabrication effects (defective welds, residual stresses), with effects of fluctuating stresses being of secondary importance. Therefore, classical elastic fatigue theory based on stress range of applied loading is not applicable to assess safety against cracking. Based on experiences with orthotropic deck bridges, an empirical approach is required and has been introduced in the Eurocode and other design specifications for steel bridges. The cost of orthotropic decks may be reduced and their structural efficiency enhanced by the use of longer rib spans and simplification of details. Standardization and serial production of prefabricated deck panels would help to further increase the acceptance and utilization of orthotropic decks.
Keywords: orthotropic decks, steel bridges, fatigue, cracking, prefabrication, design specifications.