I have a beam of 6.6m length. 3 point loads of 35kN are acting at 1.65m c/c. Section modulus required is 615,790mm3, It means if we use Beam size of 500x4x150x8 (Section modulus = 761,697), it must pass with stress ratio of 0.808 (615,790 / 761,697). But designing in SAP for same beam and loading is giving me stress ratio of 4.041. Why there is huge difference?
Model is attached herewith.
please guide me as it is little urgent.
Beam 1.SDB