1. The problem statement, all variables and given/known data We need to design the cross section of a beam to make it suitable to carry a uniformly distributed load. The beam is held up by 4 ropes which are shown on my diagram as R. In the same attached picture I have the shear diagram and the bending moment diagram for this beam. 2. Relevant equations σ(Bending)=My/I I=(bh^3)/12 3. The attempt at a solution If I choose a material with a yield (I assume the applied stress shouldn't exceed the yield) of 414MPa. The max bending moment is 232kNm. So y/I = 414/0.232 = 1780 I chose a rectangular cross section, as this resists bending in 1 plane well, with a ratio of height to bredth of 2:1 I=bh^3/12=(h/2)(h^3)/12 = h^4/24 y=h/2 ∴y/I = 12/h^3 h=(12/1780)^1/3=18.9cm So the beam is 18.9cm x 9.4cm. Edit: I amended the calculations because I realised I had used MN for bending moment (should be kN). But finally, I think the beam would be safe to carry this load with the cross section of dimensions given above. But shear wasn't considered. Anyone care to input? Would be appreciated.