If a hollow shaft of inside diameter 09 times outside

Question

Select a diameter of a steel driveshaft that transmits 250 hp at 5000 rpm. Bending and axial loads are negligible.

(a) What is the nominal shear stress at the surface?

(b) If a hollow shaft of inside diameter 0.9 times outside diameter is used, what outside diameter would be required to give the same outer surface stress?

(c) How do the weights of the solid and hollow shafts compare?