3 IS points Find the most economic beam section for the foll

3. (IS points) Find the most economic beam section for the following loading condition based on flexure ONLY. Note that there is a bracing at the center of the span. Neglect beam\'s self-weight. k/ft. k/ft. | Live Load (4.2 + x = Dead Load (6+X bracing (28 +X

Solution

total dead load = 6+5.92=11.92 kip/ft

total live load = 4.2+5.92=10.12 kip/ft

factored load on beam = (1.2*11.92)+(1.6*10.12)=30.496 kip/ft

span of beam = 28+5.92=33.92 ft

design moment in beam = 30.496*33.92²/8=4385.96 kip-ft

unbraced length of beam = 33.92/2=16.96 ft

the lightest beam that has flexural capacity greater than 4385.96 kip-ft for unbraced length of 16.96 ft is W44x262