Beer & Johnston — Torsion: Problem 3.96

3.96 The solid shaft shown is made of a mild steel that is assumed to be elastoplastic with \(\tau_Y = 145 \text{ MPa}\). Determine the radius of the elastic core caused by the application of a torque equal to \(1.1 T_Y\), where \(T_Y\) is the magnitude of the torque at the onset of yield.