Nonlinear dynamic behaviors of rod fastening rotor-hydrodynamic journal bearing system

The model of a rod fastening rotor-finite length journal bearing system is established in this paper. The contact surfaces between the disks and rods are modeled as bending resistance springs with nonlinear stiffness. The gyroscopic effect is considered in the 12 degrees-of-freedom model of the rod fastening rotor-bearing system. Based on the variational principle, an approximate analytical solution of nonlinear oil film forces of finite length journal bearing is proposed by the separation of variables method. By taking rotating speed, eccentricity and bending stiffness as control parameters, the nonlinear behaviors of the system are investigated by the improved Newmark method. The numerical results reveal periodic, period-doubling, period-4, quasi-periodic solutions etc. of rich and complex nonlinear behaviors of the system.