Question

A 300-mm diameter solid disk is to be used as a flywheel in a machine to reduce speed fluctuations. If the disk material has yield strength S Y =720 MPa, density p=7000 kg/m^ 3 . and Poisson's ratio J = 0.2 ^ c , find the maximum allowable rotational speed (in rpm) for a safety factor of 1.

a) Solve using the MSST.

b) Solve assuming that the disk is mad of cast iron having Sut = 207MPa , Fuc = 780MPa, p = 7000 kg/m³, and Poisson's ratio v r = 0.26 , Use Coulomb-Mohr theory.