고체역학 (Beer) — Torsion: Problem 3.37

3.37 The aluminum rod \(BC\) (\(G = 26\text{ GPa}\)) is bonded to the brass rod \(AB\) (\(G = 39\text{ GPa}\)). Knowing that each rod is solid and has a diameter of \(12\text{ mm}\), determine the angle of twist (a) at \(B\), (b) at \(C\). Given from Figure P3.37: Support at \(A\) is fixed. Segment \(AB\) (Brass): length \(L_{AB} = 200\text{ mm}\), \(G_{brass} = 39\text{ GPa}\). Segment \(BC\) (Aluminum): length \(L_{BC} = 300\text{ mm}\), \(G_{al} = 26\text{ GPa}\). Diameter for both rods: \(d = 12\text{ mm}\). Applied torque at free end \(C\): \(T = 100\text{ N}\cdot\text{m}\).