Vibrational Analysis of Gas Turbine Rotor

The results of the torsional analysis indicate that the resonance frequencies aresufficiently away from the operating speed. The maximum value of the magnification factor is 6.49hence the Short circuit torque value is well within the allowable transient torque. Campbelldiagram shows there is no interference between calculated torsional natural frequencies in therange of ±10% of the operating speed of the rotor train. The maximum torsional stress for the eventsthat were studied for the weakest section of shaft was 39.65 ksi which are well within the acceptedlevel. The calculated response levels for this system have been accepted based upon the yieldstrength of the component materials. The resonant alternating shear stresses are well within theaccepted level based upon the yield strength of the component materials. The objective of shortcircuit events is to avoid component outer-fibre yielding while for the malsynchronizationevents avoiding full-screen yield is the primary objectiveThere are no torsion natural frequencies alternating shear stress nor electrical faulttorque concerns for the system based on the analysis performed on this rotor train. The rotor issafe under three-phase short circuit analysis