Prob. 4.3-1. A bimetallic torsion bar consists of a steel core (G,= 75 GPa) of diameter d = 25 mm around which is bonded a titanium sleeve (G, = 45 GPa)

of inner diameter d, = 25 mm and outer diameter d, = 40 mm. (a) If the max- imum shear stress in the steel is 50 MPa, what is the total torque, T, applied to the bimetallic bar? (b) What is the total twist angle of the composite bar if it is 2 m long?