“Critical Speed Analysis of Offset Jeffcott Rotor Using English and Metric Units,”
A uniform rotor of length L=1000 mm and D=50 mm was assumed. A disk of diameter Ddisk=500mm and thickness t=50 mm is attached at the quarter span at 250 mm from the left end bearing. The disk and shaft are assumed to be of steel with E=30E6 Lb/in and disk density of 0.283 Lb/in3. Models were generated with Dyrobes using English and metric system of units. As a check on the accuracy of the calculations, the critical speeds were also computed using the critical speed program CRITSPD-PC which is a transfer matrix program developed by Gunter and Gaston for use by industry.