A steel beam ABC is simply supported at A and B and has an overhang BC of length L= 150 mm (see figure). The beam supports a uniform load of intensity q = 4.0 kN/m over its entire span AB and 1.5q over BC. The cross section of the beam is rectangular with width b and height 2b. The allowable bending stress in the steel is σallow = 60 MPa, and its weight density is 77.0 kN/m3 .
(a) Disregarding the weight of the beam, calculate the required width b of the rectangular cross section.
(b) Taking into account the weight of the beam, calculate the required width b.
