Nonlinear Dynamic Response of a Rotor Bearing System Due to Surface Waviness

In this paper, the radial vibrations of a rigid rotor supported by ball bearings are studied. In the analytical formulation, contacts between the balls and races are considered as nonlinear springs whose stiffnesses are obtained by using Hertzian elastic contact deformation theory. The implicit type numerical integration technique Newmark-β with the Newton-Raphson method is used to solve the nonlinear differential equations iteratively. The effect of bearing running surface waviness on the vibrations of rotor is investigated. The formulation predicts discrete spectrum with specific frequency components for each order of waviness. Numerical results obtained from the simulation are validated with respect to those of prior researchers.