Hi, I'm having difficulty with an assignment. Briefly, the question relates to a simply supported I beam containing a UDL and a point load. I've calculated the maximum bending moment resulting from these loads (neglecting beam mass) to be 5625kNm. I must select a universal beam from grade 43 steel (yield = 275 MN/m2) that can support this loading scenario. Long story short, using this material the required elastic section modulus (20454.55cm3) is just too high for any standard beams. I've been told I cannot change the material, loading or fixing scenerio and that I have to 'find a way around' the problem. Approach 1 I was considering using the UTS for grade 43 steel (430 MN/m^2) which would solve the problem, but that surely doesn't lend itself well to sound engineering practice. Approach 2 The other thing I found is that on http://www.corusconstruction.com/en..._beams_structural_steel/use_of_bs5950_part_1/ moment capacity for a simply supported beam is the lesser of Mc = py.Sx and Mc = 1.2 py.Zx Where Py is material yield strength, Sx is plastic section modulus and Zx is elastic section modulus. I have read BS 5950 and it seems to back this up. Approach 3 Could I stack two I beams on top of each other? How would this affect the second moment of area (would it be double, or .. just over double of one beam)? I am confident I could produce answers which make sense (to me) but I obviously need to produce answers that have resulted from sound engineering process. Which approach should I use? Or maybe none of the above!? Any help would be appreciated.