고체역학 (Beer) — Torsion: Problem 3.124

3.124 Knowing that the magnitude of the torque \( T \) is 200 N·m and that \( G = 27 \text{ GPa} \), determine for each of the aluminum bars shown the maximum shearing stress and the angle of twist at end \( B \). From Figure P3.123 and P3.124: - Length of both bars: \( L = 900 \text{ mm} \) - Bar (a): Square cross-section with side \( a = 25 \text{ mm} \) - Bar (b): Rectangular cross-section with width \( a = 45 \text{ mm} \) and thickness \( b = 15 \text{ mm} \)