Question

10. A cast iron wheel of mean diameter 3 metre has six arms of elliptical section. The energy to be stored
in it is 560 kN-m when rotating at 120 r.p.m. The speed of the mean diameter is 18 m/s. Calculate the
following:
(a)Assuming that the whole energy is stored in the rim, find the cross-section, if the width is 300 mm.
(b)Find the cross-section of the arms near the boss on the assumption that their resistance to bending
is equal to the torsional resistance of the shaft which is 130 mm in diameter.
The maximum shear stress in the shaft is to be within 63 MPa and the tensile stress 16 MPa. Assume
the minor axis of the ellipse to be 0.65 major axis.

Answer 1