Transient dynamic analysis for a rotor-bearing system based on energy equations

Dynamic model of a rotor-journal bearing system under base shock excitations was established. Energy differential equations were derived by applying Lagrange equation with FE in space domain. Bending and shear deformation energy of shaft element were taken into account. Inertia force due to rotor mass eccentricity was introduced and treated as a generalized external force. Oil-film force was determined by eight coefficients, namely, four stiffness coefficients and four damping coefficients. Newmark numerical algorithm was used to solve dynamic equations. Time-varying dynamic responses are obtained successfully. Finally, the utility and validity of the proposed method were confirmed by an application example-a propulsion shaft system subjected to base shock excitations.