Question

A cantilever bean is 12 feet long and has a uniformly distributed dead load of 600 lbs/ft and a uniformly distributed live load of 1000 lbs/ft. Design the beam for flexure assuming it is continuously braces by a floor/deck system. Use 36 ksi steel.

a) draw Free body Diagram/ shear + moment diagram to find Mu Max

b) Solve for Zx based on Mu Max

c) Select beam from table 9.1

d) Check compactness criteria

e) if compactness works, recalculate Mu Max adding in beam weigh (Dead Load)

f) compare o/ Mn to Mu Max

g) Deflection Check

Answer 1

the question was quit lengthy , I have solved the main design part A B C D G part of the question due to time constraint.

keep in mind while selecting the section from table , to take the account of weight of the section which will effect the required Z value .

take the factor of safety for DD nd Lload , as stated I the answer

compactness of the web nd flange I have mentioned in the answer , take care of the formula to calculate if the section is compact or semi compact

for deflection in the steel beam , the formula account only live load , hence it was safe under deflection criteria .

if u have any doubt , feel free to drop a comment below.