고체역학 (Beer) — Torsion: Problem 3.47

3.47 Solve Prob. 3.46, assuming that both shafts are made of a brass with \(G = 5.6 \times 10^6 \text{ psi}\) and \(\tau_{\text{all}} = 8 \text{ ksi}\). (Prob. 3.46 statement: The design specifications for the gear-and-shaft system shown require that the same diameter be used for both shafts and that the angle through which pulley \(A\) will rotate when subjected to a 2-kip·in. torque \(T_A\) while pulley \(D\) is held fixed will not exceed \(7.5^\circ\). Determine the required diameter of the shafts if both shafts are made of a steel with \(G = 11.2 \times 10^6 \text{ psi}\) and \(\tau_{\text{all}} = 12 \text{ ksi}\).)