Numerical investigation with rub-related vibration in rotating machinery

Nonlinear behavior of rub-related vibration in rotating machinery is studie d with a large number of numerical simulations. A simplified model is used to capture the dynamic response of the rotor when it rubs its housing. It i s shown that the model displays rich dynamics, many of which are rather com plicated and cannot be captured with linear models. The effects of rotating speed, clearance, damping coefficient, friction coefficient, and boundary stiffness are investigated. The data generated are displayed graphically an d explained with the aid of the theory of modem nonlinear dynamics. It is d emonstrated that the system goes through an extraordinary route to chaos an d that the stretching, contraction, and folding of initial volumes may indi cate the existence of a horseshoe map, which plays an important role in cre ating chaotic phenomena. These results help engineers to optimize the desig n of rotating machinery, as well as to develop sensitive monitoring/diagnos is systems assessing machinery conditions.