Generalized model of imperfection forces for design of transverse roof bracings and purlins

• Autorzy: Biegus A. , Czepiżak D.

Identyfikatory

DOI

10.1016/j.acme.2017.07.002

• Języki publikacji: EN

Abstrakty

EN

The EN 1993-1-1 calculation model of initial, equivalent bow imperfection forces qd acting on the bracing system assumes that the stabilized member is uniformly compressed within his length. But this assumption is incorrect. The distribution of the axial compression force in the restrained roof rafter varies along its length and usually has a parabolic shape. This paper proposes refined generalized models for identifying the imperfection forces in members to be restrained, having an initial bow imperfection with maximum amplitude e0. The models were derived on the basis of the real parabolic shape of the axial forces distribution in restrained roof girders. The effect of lateral imperfection amplitude e0 of the restrained girder is accompanied by twist imperfection ϕ0 measured as the angle of rotation of the webbed girder plane or the plane passing through the truss top and the bottom chords. The latter imperfection profile component generates additional horizontal imperfection forces H1,i not included in the current design codes. Analytical relations for calculating imperfection force qdi and force H1,i are provided in order to evaluate the state of stress in both the purlins and the bracings. The considered problem is illustrated with a calculation example.

Słowa kluczowe

EN

imperfection load; roof girder; member to be restrained; purlin; bracing

PL

obciążenie imperfekcyjne; płatew; belka dachowa; stężenie

• Wydawca: Springer ; Wrocław University of Science and Technology
• Czasopismo: Archives of Civil and Mechanical Engineering
• Rocznik: 2018
• Tom: Vol. 18, no. 1
• Strony: 267--279
• Opis fizyczny: Bibliogr. 16 poz., rys., tab., wykr.

Twórcy

autor

Biegus A.

• Wrocław University of Science and Technology, Faculty of Civil Engineering, ul. Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland

autor

Czepiżak D.

• Wrocław University of Science and Technology, Faculty of Civil Engineering, ul. Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland

Bibliografia

• [1] A. Biegus, Calculation of lateral bracing for cantilever and multispan girders, Archives of Civil and Mechanical Engineering 13 (2013) 99–103.
• [2] D. Czepiżak, A. Biegus, Refined calculation of lateral bracing systems due to global geometrical imperfections, Journal of Constructional Steel Research 119 (2016) 30–38.
• [3] W.F. Chen, T. Atsuta, Theory of Beam-Column, MacGraw- Hill, New York, 1961.
• [4] B. Davison, G.W. Owens, Steel Designer's Manual, 7th ed., The Steel Construction Institute, Wiley-Blackwell, 2012.
• [5] M. Gardner, D. Nethercot, in: H. Gulvanessian (Ed.), Designers Guide to EN 1993-1-1: Eurocode 3 Design of Steel Structures. Part 1-1: General Rules and Rules for Building, Thomas Telford Limited, London, 2005.
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• [8] EN 1993-1-1, Eurocode 3: Design of Steel Structures. Part 1-1: General Rules and Rules for Building, CEN, Brussels, 2005.
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• [12] S.Z. Pałkowski, M. Piątkowski, On the calculation of lateral roof bracing, Inżynieria i Budownictwo 4 (2014) 210–213 (in Polish).
• [13] Schneider, Bautabellen für Ingenieure mit Berechnungshinweisen und Beispielen, 22. Auflage, Bundesanzeiger Verlag, 2016.
• [14] J.C. Taylor, et al., Interim Guidance on the Use of Eurocode 3: Eurocode 3 Part 1-1: for European Design of Steel Building Structures, The Steel Construction Institute, Ascot, 1995.
• [15] N.S. Trahair, M.A. Bradford, D.A. Nethercot, L. Gardner, The Behavior and Design of Steel Structures to EC3, Taylor and Francis, London, New York, 2008.
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Uwagi

PL

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018)