A rectangular beam with b = 70 mm and h = 120 mm (Fig. P12.15) is subjected to an ultim...

A rectangular beam with b = 70 mm and h = 120 mm (Fig. P12.15) is subjected to an ultimate moment Mu. Knowing that = 250 MPa for this beam of ductile material, determine the residual stresses at the upper and lower faces if the loading has been removed.