A rotor-support-case system simulated test rig was established by considering the structure characteristics and dynamic characteristics in blade to case rub-impact of aero-engine.The responses of both slight rub-impact and serious rub-impact were measured.Time frequency analysis methods
continuous wavelet transform and wavelet packet energy were used to perform the feature extraction of rotor and case.The results indicate that the response of case contents both high frequency signal and low frequency signal. The high frequency signal in case is mainly attributable to impact during slight rub-impact
and the friction effect is improved in serious rub-impact.As a conclusion
it may play a role in rub-impact fault diagnosis and identification.