By using the " stress intensity factor be zero" method

the vibration models for both open crack and breathing crack rotor during the turbine rotor speeding up process were established.The Runge-Kutta method was applied to carry out numerical integration for the models

to realize steady state response numerical simulation and stability quantitative analysis for the two types of rotor during speeding up process.The results show that

obvious 1/3and 1/2order superharmonic resonance phenomenon occurs on both the open crack rotor and breathing crack rotor in the process of speed up.In the supercritical speed zone

a subharmonic resonance phenomenon appears on both the open crack rotor and breathing crack rotor with the rotating speed ratio of 2.1

2.2and 2.55.This phenomenon can be considered as the basis for judging whether the rotor crack fault exists.In different rotating speed areas

the open crack rotor behaves differently from the breathing crack rotor

especially in the supercritical speed zone

the mass eccentricity e further counterpoises the nonlinear instability caused by the crack

a local asymptotic stability region appears on the breathing crack rotor

especially when the mass eccentricity e are higher than 0.8but lower than1.6

the mass eccentricity will enhance the nonlinear instability.This phenomenon can provide theoretical basis for control of nonlinear motion instability of crack rotors.