고체역학 (Gere) — Torsion: Problem 3.3-5

3.3-5 A prospector uses a hand-powered winch (see figure) to raise a bucket of ore in his mine shaft. The axle of the winch is a steel rod of diameter \(d = 15 \text{ mm}\). Also, the distance from the center of the axle to the center of the lifting rope is \(b = 100 \text{ mm}\). (a) If the weight of the loaded bucket is \(W = 400 \text{ N}\), what is the maximum shear stress in the axle due to torsion? (b) If the maximum bucket load is \(510 \text{ N}\) and the allowable shear stress in the axle is \(65 \text{ MPa}\), what is the minimum permissible axle diameter?