The composite shaft is made of a steel sleeve, which is bonded to a brass core. The outer diameters of the two parts are d1 = 40 mm for the brass core and d2 = 50 mm for the steel sleeve. The shear moduli of elasticity are Gb = 36 GPa for the brass and Gs = 80 GPa for the steel. Assuming that the allowable shear stresses in the brass and steel are ?b = 48 MPa and ?s = 80 MPa, respectively, determine the maximum permissible torque Tmax that may be applied to the shaft without any material failure. The torques are applied each at the end of the shaft opposite directions.