Design of Rolled Steel Beams:
It is assumed that you can draw the bending moment and shearing force diagrams for the beam. From this the maximum BM and SF to which the beam is subjected can be ascertained. The various types of stresses (bending and shear) can then be calculated as outlined above.
Selection of Beam Section
Compute the section modulus from all the known values of bending moment M, and permissible bending stresses in tension (σbt) or compression (σbc).
Zt = M/ σbt or Zc = M/σbc