The coupling free vibration characteristics of a rotating functionally graded shaft-disk system in thermal field

The numerical model of a functionally graded (FG) shaft-disk rotor system with flexible shaft and flexible various-thickness disk as components is established to investigate the coupling free vibration behavior of this rotor system in thermal field. Considering the thermophysical properties of the material, the properties of functionally graded material vary continuously according to the power law with the thickness of the disk. Based on the theory of rotor dynamics, the kinetic energy expression and strain energy expression of rotating shaft-disk system are obtained. In the framework of Ritz method, the global control differential equation of the rotor system assembled by shaft and FG disk is established by using differential quadrature finite element method. On this basis, a set of numerical examples are presented to perform convergence, correctness and effectiveness verification of the current model. Moreover, the influence of temperature difference, rotating speed, geometric and material parameters on the thermoelastic coupling vibration characteristics of lightweight shaft-disk rotor is discussed in detail, which can help to improve the rotor vibration performance in design work and future research.