Critical speeds of a flexible rotor with combined distributed parameter and lumped mass technique

Abstract A new method is proposed for calculating the critical speeds of a general flexible rotor supported by flexible or rigid bearings. The method takes into account the gyroscopic effect of the rotor as well as the distributed mass and inertia of the shaft along with the transverse shear effect. Many other rotor parameters like bearing mass, bearing damping, coupling flexibilities, external loads, etc., are also taken care of. The validity of the mathematical formulation and the computer program developed is verified with the aid of available results and, as an illustration, the effect of coupling flexibilities on critical speeds is also investigated.