고체역학 (Gere) — Torsion: Problem 3.5-8

3.5-8 A solid circular bar of steel (\(G = 78 \text{ GPa}\)) transmits a torque \(T = 360 \text{ N}\cdot\text{m}\). The allowable stresses in tension, compression, and shear are \(90 \text{ MPa}\), \(70 \text{ MPa}\), and \(40 \text{ MPa}\), respectively. Also, the allowable tensile strain is \(220 \times 10^{-6}\). (a) Determine the minimum required diameter \(d\) of the bar. (b) If the bar diameter \(d = 40 \text{ mm}\), what is \(T_{\text{max}}\)?