Steel Buildings in Europe

Title APPENDIX D Worked Example: Design of portal frame using elastic analysis 33 of 44 4 - 114 7.10.1. Flexural buckling resistance about the mayor axis, N b,y,Rd b h  190 450  2,37 t f  14,6 mm buckling about y-y axis:  Curve a for hot rolled I sections    0,21 EN 1993-1-1 Table 6.1 Table 6.2 The buckling length is the system length, which is the distance between the joints (i.e. the length of the rafter, including the haunch), L = 15057 mm  1 = y f E  = 355 210000  = 76,4 EN 1993-1-1 §6.3.1.3 y  = y 1 cr 1  i L = 76, 4 1 185 15057  = 1,065  y =     2 y y y 0,2 0,51        y =     2 0,51 0,211,065 0,2 1,065    = 1,158 EN 1993-1-1 §6.3.1.2  y = 2 y 2 y y 1      = 2 2 1,158 1, 065 1,158 1   = 0,620 N b,y,Rd = M1 y y   Af = 3 10 1, 0 355 9880 0, 620     = 2175 kN N Ed = 127 kN < 2175 kN OK 7.10.2. Lateral-torsional buckling resistance, M b,Rd M b,Rd is the least buckling moment resistance of those calculated before. M b,Rd =   min 581; 540 M b,Rd = 540 kNm 7.10.3. Interaction of axial force and bending moment – in-plane buckling In-plane buckling due to the interaction of axial force and bending moment is verified by satisfying the following expression: 1, 0 b,Rd y,Ed yy b, y,Rd Ed   M M k N N The interaction factor, k yy , is calculated as follows: k yy =                              b, y,Rd Ed my b, y,Rd Ed y my 1 0,8 ; 0, 2 1 min N N C N N C 