고체역학 (Gere) — Torsion: Problem 3.4-18

3.4-18 A prismatic bar $AB$ of length $L$ and solid circular cross section (diameter $d$) is loaded by a distributed torque of constant intensity $t$ per unit distance (see figure). (a) Determine the maximum shear stress $\tau_{\text{max}}$ in the bar. (b) Determine the angle of twist $\phi$ between the ends of the bar.