Albero V.,Polytechnic University of Valencia |
Espinos A.,Polytechnic University of Valencia |
Romero M.L.,Polytechnic University of Valencia |
Hospitaler A.,Polytechnic University of Valencia |
And 2 more authors.
Engineering Structures | Year: 2016
Previous investigations proved the unsafety of the current design guidelines in Annex H of EN 1994-1-2 for the calculation of the fire resistance of slender concrete-filled steel tubular (CFST) columns. In this paper, a new simplified design method based on the general rules in Clause 18.104.22.168 of EN 1994-1-2 is presented for correcting this inaccuracy. For the development of the method, an extensive parametric study consisting of about 20.500 analysis cases was carried out by using numerical models, which in turn were validated against a wide range of experimental results. The proposed method provides a significant extension over the current EN 1994-1-2 applicability limits, reaching high member slenderness, large eccentricities and being valid for all the commercially available geometries, including elliptical hollow sections. The design proposal is divided into two parts: thermal, where a simplified cross-sectional temperature field can be obtained based on equivalent temperatures for the composite section constituents, and mechanical, where a full method for evaluating the ultimate buckling load in the fire situation is given. The proposed method is valid for axially and eccentrically loaded columns, accounting for eccentricities on both minor and major axis and reaching large eccentricities of e/D = 1. Finally, it is proved that the proposed method provides safe predictions as compared to experimental results and meets the CEN/TC250/SC4 accuracy criteria. © 2016 Elsevier Ltd
Skejic D.,University of Zagreb |
Lukic M.,Center Technique Industriel Of La Construction Metallique Cticm |
Buljan N.,ISA Group |
Vido H.,ISA Group
Key Engineering Materials | Year: 2016
Curtain wall industry is the major user of aluminium as a structural material in buildings, with two basic curtain wall systems: stick and unitised. The latter is preassembled in shops, with the main feature that frame profiles are split in two interlocking halves. Such cross sections are complex, open and prone to lateral torsional buckling. General formulas for the calculation of elastic critical moment for lateral-torsional buckling are provided in the EN 1999-1-1, with a long and complicated procedure for non-symmetrical sections which makes it pretty impractical for everyday use. The problem of such sections can also be assessed by FEM modelling, which is a time consuming and complex process. Curtain wall industry is in a need of a swift, if approximate and conservative, method for checking the risk of lateral torsional buckling of profiles with nonsymmetrical cross sections. Some available analytical methods are applied on a practical example and their results compared to those obtained using FEM modelling. © 2016 Trans Tech Publications, Switzerland.