Nonlinear dynamic behaviors of a rod fastening rotor supported by fixed–tilting pad journal bearings

A rod fastening rotor with the fixed–tilting pad journal bearings support is modeled. The rotor is connected by rods, where the rods and connection surfaces of disks are considered as resistance bending springs with nonlinearity, and the inertia of the tilting pads is considered in the modeling. The nonlinear oil film forces of the fixed–tilting pad journal bearings are obtained by the database method. The nonlinear dynamic behaviors and bifurcation of the rotor-bearing system is investigated by the orbit diagrams, the time series, the frequency spectrum diagrams, and the Poincaré maps. The comparison of the orbits between the rod fastening rotor and integral rotor system is implemented, and the results reveal that the rod fastening rotor system is more stable than the integral rotor system. The orbits of the rotor system and the pendulum angles of pads are also studied at different preloads and pivot ratios.