고체역학 (Gere) — Torsion: Problem 3.11-7

3.11-7 A thin-walled steel tube having an elliptical cross section with constant thickness \(t\) (see figure) is subjected to a torque \(T = 5.5 \text{ kN}\cdot\text{m}\). Determine the shear stress \(\tau\) and the rate of twist \(\theta\) (in degrees per meter) if \(G = 83 \text{ GPa}\), \(t = 5 \text{ mm}\), \(a = 75 \text{ mm}\), and \(b = 50 \text{ mm}\). Note: See Appendix E, Case 16, for the properties of an ellipse.