고체역학 (Gere) — Torsion: Problem 3.8-3

3.8-3 A solid circular shaft \(AB\) of diameter \(d\) is fixed against rotation at both ends (see figure). A circular disk is attached to the shaft at the location shown. What is the largest permissible angle of rotation \(\phi_{max}\) of the disk if the allowable shear stress in the shaft is \(\tau_{allow}\)? [Assume that \(a > b\). Also, use Eqs. (3-50a and b) of Example 3-9 to obtain the reactive torques.]