Finite Element Modelling and Dynamic Stability Analysis of a Functionally Graded Rotor Shaft-Bearing System

The extensive analyses of rotor-bearing-disk systems are inevitably a challenging problem to get the exact results. In the development of the current industries, based on the specific applications the functionally graded (FG) rotating shafts are used extensively. It is observed that very few studies were reported on FG rotor-bearing-disk systems on stability issues. The current study carries the finite element (FE) dynamic modelling approach, and the stability study of a rotating FG rotor-disk-bearing system. The FG rotor shaft model is considered to be based on Timoshenko beam theory by accounting for the gyroscopic effects, rotary and translational inertia, shear deformation, bending and material (viscous and hysteretic) damping. The governing equations are obtained by implementing Hamilton’s principle. In the present study, stainless steel (SUS304) and Zirconia (ZrO2) are typically treated as main components which are radially categorized FG shaft. Five-noded beam elements are considered by taking into account of four degrees of freedom per node. The results from Campbell diagram, stability threshold, time histories and damping ratio for FG shaft are compared with the regular standard steel shaft. It is observed that the results obtained for FG rotating shaft are notably controlled by the constituents of the radially classified FG shaft. This result leads to the importance of FG shaft over the standard steel shaft.