The composite shaft shown in the figure is manufactured by shrink-fitting a steel sleeve over a brass core so that the two parts act as a single solid bar in torsion. The outer diameters of the two parts are d1 = 1.6 in. for the brass core and d2 = 2.0 in. for the steel sleeve. The shear moduli of elasticity are Gb = 5400 ksi for the brass and Gs = 12,000 ksi for the steel.
Assuming that the allowable shear stresses in the brass and steel are Tb = 4500 psi and Ts = 7500 psi, respectively, determine the maximum permissible torque T max that may be applied to the shaft. (Use Eqs. 3-44 a and b to find the torques.)