Steel Buildings in Europe

Title APPENDIX D Worked Example: Design of portal frame using elastic analysis 36 of 44 4 - 117 Upper web By inspection the upper web will be Class 3 or better, because it is mostly in tension. Lower web Stress in the section caused by axial load:  N = 3 10 15045 129  = 8,57 N/mm 2 Assuming an elastic stress distribution in cross-section No.1, the maximum stress available to resist bending is:  M = N M0 y    f = 8,57 1, 0 355  = 346 N/mm 2 953 450 503 451,4 501,6 31 N/mm² 346 N/mm² The distance from the bottom flange to the elastic neutral axis is: z = 451,4 mm Distance from underside of middle flange to neutral axis: 51,6 mm Bending  axial stress at the top of cutting section: =   51, 6 451, 4 8,57 346   =  31 N/mm 2