Abstract: The clearance between rotor and stator in rotating machinery becomes smaller to supply high speed and efficient. Local rub failure often occurs which can lead to nonlinear response in the whole rotor system. Timely obtained dynamic characteristics are vital to the fault in rub rotor system. Based on the finite element and the harmonic balance theory， the relationship between harmonic components of vibration responses and frequency response matrix was used to obtain local rub failure transfer mechanism. Validity and robustness were verified by numerical simulations and experiments. Responses of n+2 nodes were needed to obtain responses of the all remaining nodes in n malfunctions of rotor system. The transfer mechanism has a good applicability in rotor system aiming at the rub， misalignment， unbalance and crack.

Key words: rotor system, nonlinear response, harmonic components, rub, fault transfer mechanism