Steel Buildings in Europe

8 - 18 Worked Example 2: Combined axial force and bending moment (N-M Interaction) 1 of 5 Made by CZT Date 02/2010 Calculation sheet Checked by ENM Date 02/2010 1. Combined axial force and bending moment This example presents the method used in the member resistance calculator for calculating the out-of-plane buckling resistance and in-plane buckling resistance, adopting the recommended values of EN 1993-1-1. References are to EN 1993-1-1 unless otherwise stated Section: IPE 450 Steel grade: S355 N Ed  127 kN M y,Ed  356 kNm (bending moment constant along the beam) M z,Ed  0 kNm L y = L z = L LT = L cr = 1,7 m 1.1. Cross-section classification 1.1.1. The web w t c = 9,4 378,8 = 40,3 Table 5.2 (Sheet 1) d N = w y Ed t f N = 9, 4 355 127000  = 38  = w w N 2 d d d  = 2 378,8 378,8 38   = 0,55 > 0,50 The limit between Class 1 and Class 2 is : 13 1 396    = 13 0,55 1 396 0,81    = 52,1 Then : w t c = 40,3 < 52,1  The web is class 1. 1.1.2. The flange f t c = 14, 6 69,3 = 4,7 The limit between Class 1 and Class 2 is : 9 ε = 9  0,81 = 7,3 Then : f t c = 4,7 < 7,3  The flange is Class 1 Table 5.2 (Sheet 2) Therefore, the section is Class 1. The verification of the member will be based on the plastic resistance of the cross-section.