Question

An 8m span sim ply supported beam is laterally unsupported between both ends . The beam is bent about its m inor axis and is subject to thre e concentrated factored forces of 100 kN each, acting at quarter span , midspan and three quarter sp an points. It is required to find an econom ic section to carry the given loads. (F y=350MPa). Perform all the necessary checks to carry the applied loads. You can neglect the self weight of the beam.

Answer 1

Solue 100 IN dooien 100 IN B © 2n. RB RA 0 afy RAT RB 100f 100+ Loo RA & RB 300 IN Talking Moment about B SMB=0 Raud - (1006) -(10004) -(100~2) = 0 RA 600 + 400 + 200 150 len S RA RB 1200 8 150 len. moment at 300 KNM. Bending Binding Bending 400 KNM. moment at C 15002 moncent at D (150204) - (100% 2 - 600 - 200 monent at E = (15046) - (10084) -(10042) goo 400-200=300KNN Bending Sending moment at B = (5009) - (com) - Goomy) -(1002) 600 - 400-200 1200 o

Clien, 350 repa. by Max Bon = 400 KNM. using bending equation dy 9 I as 350 у 2100 x 106 350 I Y 4100x106 I 1142857.1434®=(2) (Section modulusy using I I dection with Section modulus. W(12045) (2) of: 1295605.307 mp3 30125 MM. depth 12.06 inch a