Numerical study of an anisotropically supported rotor with parametric excitation

Abstract

Anisotropic structures, e.g. oil journal bearings are often employed as supporting structure for rotating machineries. Moreover, cross-section of rotating element is often non-symmetrical due to various practical reasons. This paper investigates the dynamics of a parametrically excited rotor-support system. The mathematical model of a rotor supported by an anisotropic structure in the middle and supported rigidly at the far-ends is devised. Stability analysis in the rotating speed domain is demonstrated using two numerical approaches based on Runge–Kutta method and Floquet Theory. The performance of these two methods in terms of computational cost and accuracy is compared. In addition, the influence of cross-coefficient stiffness and damping of the anisotropic support on the unstable region is discussed.