Question

A solid steel shaft, 20 mm in diameter and 1 m long, is placed concentrically inside a hollow

duralumin shaft with inside and outside diameters of 30 mm and 33 mm respectively and a

length of 500 mm. The ends of the hollow shaft are rigidly fixed to the solid shaft. Determine

(a) the torsional stiffness of the composite shaft

(b) the maximum torque to which the composite shaft may be subjected if the allowable

shear stresses for steel and duralumin are 90 MPa and 30 MPa respectively

(c) the total angle of twist if the shaft is subjected to the torque determined in (b)

(GDU = 25 GPa; GST = 84 GPa).

Answer 1