Dynamic Response Analysis of Dual-Rotor System with Rubbing Fault by Dimension Reduction Incremental Harmonic Balance Method

Abstract

The dimension reduction incremental harmonic balance (DRIHB) method is developed to study the dynamic behavior of dual-rotor system with multi-frequency excitations and nonlinear rubbing faults. On the basis of consideration of an aero-engine, a dynamic model of rotor system is built and the piecewise-nonlinear model of rubbing force is used to investigate the nonlinear behavior of system. Considering the features of multi-frequency excitation, high dimension and strong nonlinearity of dual-rotor system, the dimension reduction approach combined with the incremental harmonic balance (IHB) method is derived for theoretically studying the dynamic response of system with nonlinear rubbing fault. The accuracy and efficiency of the method are proved through comparison with the numerical simulation result solved by the Newmark-[Formula: see text] method and the IHB method. Then, the influences of rubbing stiffness, contact gap, rotational speed and speed ratio on dynamic response are studied and discussed. It is shown that the dual-rotor system with nonlinear rubbing fault will cause the system to generate rich combination frequency components in addition to excitation frequency. All the works indicate that the DRIHB method is an effective tool for studying the nonlinear behavior of dual-rotor systems with multi-frequency excitation, high dimensions and strong nonlinearities.