Steel Buildings in Europe

Title Worked Example: Axial compression and bending interaction (N-M Interaction) 3 of 5 8 - 20 N b,y,Rd = M1 y y   Af = 3 10 1,0 355 1,0 9880     = 3507 kN N Ed = 127 kN < 3507 kN OK 1.3.2. Lateral-torsional buckling resistance for bending, M b,Rd In order to determine the critical moment of the rafter, the C 1 factor takes account of the shape of the bending moment diagram. In this case the bending moment diagram is constant along the segment in consideration, so  = 1,0. Therefore:  1 C = 1,0 Appendix C of Single-Storey Steel Building, Part 4 M cr = z 2 t 2 z w 2 z 2 1 EI L GI I I L EI C    = 2 4 2 1700 10 1676 210000 1, 0      4 2 4 2 4 9 10 1676 210000 66,9 10 81000 1700 10 1676 791 10            M cr = 2733  10 6 Nmm Appendix C of Single-Storey Steel Building, Part 4  LT  cr pl,y y M f W = 6 3 10 2733 355 10 1702    = 0,470 §6.3.2.2     2 LT LT,0 LT LT LT 0,5 1           §6.3.2.3 LT,0   0,4 and   0,75 b h  2,37  Curve c for hot rolled I sections   LT  0,49 Table 6.3 Table 6.5     2 LT 0,5 1 0, 49 0, 470 0, 4 0, 75 0, 470       = 0,60  LT = 2 LT 2 LT LT 1        LT = 2 2 0, 60 0, 60 0, 75 0, 470 1    = 0,961 §6.3.2.3 2 LT 1  = 2 0, 470 1 = 4,53 Therefore  LT = 0,961