CZASOPISMO INŻYNIERII LĄDOWEJ, ŚRODOWISKA I ARCHITEKTURY JOURNAL OF CIVIL ENGINEERING, ENVIRONMENT AND ARCHITECTURE JCEEA, t. XXXII, z. 62 (3/II/15), lipiec-wrzesień 2015, s. 425-437 Radosław SZCZERBA 1 Marcin GAJEWSKI 2 Marian GIŻEJOWSKI 3 ANALYSIS OF STEEL I-BEAM-COLUMNS CROSS-SECTION RESISTANCE WITH USE OF FINITE ELEMENT METHOD An interaction of uniaxial bending and axial compression occurs very often in en- gineering practice and has been widely described in clause 6.2 of Eurocode 3. There are appropriate formulae given to verify the design cross-section resistance of steel structural members. Numerical aspects of constructing the cross-section resistance interaction curve of I-sections are presented in this paper through nu- merical modelling of the behaviour of stocky beam-columns with the relative slenderness ratio of 0.2 that distinguishes the range of characteristic values of the cross-section resistance and the member buckling resistance. Numerical study was carried out with respect to hot-rolled wide flange HEB/HEAA sections. The case of combined planar bending about one of the section principal axis (y or z) and axial compression was considered. The scope of numerical research includes different cross-section classes from class 1 to class 4. In case of cross-sections from class 1 to class 3, Geometrically and Materially Nonlinear Analysis (GMNA) is carried out. As far as class 4 cross-sections are concerned, Geometri- cally and Materially Nonlinear with Imperfections Analysis (GMNIA) is carried out in which geometrical imperfections due out-of-flatness deformations of sec- tion plate components are taken into account in the form of first local buckling mode. Plate section components are modelled using Finite Shell Elements (FSEs). FSE modelling technique using ABAQUS/Standard library is utilized. Numerical results in the form of interaction diagrams are compared with those of analytical ones presented in Eurocode 3. Differences occurring between the results from conducted FE analysis and those obtained with use of Eurocode’s interaction for- mulae are discussed and factors causing these differences are outlined. Conclud- ing remarks are drawn. Keywords: cross-section resistance, compression and uniaxial bending, steel stocky I-beam-beams, FEM _____________________________________ 1 Corresponding author: Radosław Szczerba, Rzeszów University of Technology , ul. Poznańska 2, 35-084 Rzeszów, Tel.: +48 17 865 16 16, rszcz3rba@gmail.com. 2 Marcin Gajewski, Warsaw University of Technology, al. Armii Ludowej 16, 00-637 Warszawa, Tel.: +48 22 234 5164, m.gajewski@il.pw.edu.pl. 3 Marian Giżejowski, Warsaw University of Technology, al. Armii Ludowej 16, 00-637 Warszawa, Tel.: +48 22 234 6554, m.gizejowski@il.pw.edu.pl.