Abstract: Aiming at the diagnosis of fracture fault, a typical fault mode of gas turbine rotor blades, the sensitive vibration features and effective fault identification methods under the excitation of rotor blade fracture were studied to ensure gas turbine’s safe and stable operation. Firstly, the casingstator blade was taken as the research object. Combining with gas turbine blades’ structural and load characteristics, the dynamic model and motion equations under the fracture excitation were established based on the fault mechanism of rotor blade fracture. By solving and analyzing vibration responses, the fault mechanism feature of blade fracture was studied, and it was convenient for monitoring and analysis in engineering. Furthermore, the fault identification method based on the wavelet transform algorithm was proposed. Finally, the effectiveness of the proposed fault mechanism feature and identification method was verified by a gas turbine blade fracture fault case. The results indicate that the blade passing frequency is the main excitation frequency of the system, and its amplitude has a characteristic of step-type abrupt decreasing after the rotor blade is broken. Combining with the wavelet transform algorithm, the blade fracture fault can be effectively identified. The research results can provide a certain reference for fault diagnosis of gas turbine rotor blade fracture.

Key words: sensitive vibration features; blade fracture; fault identification methods; fault mechanism; wavelet transform

ＪＩＡＮＧ Ｚｈｉ￣ｎｏｎｇ，ＷＡＮＧ Ｚｈｏｎｇ，ＨＵ Ｍｉｎｇ￣ｈｕｉ， ｅｔ ａｌ. Ｖｉｂｒａｔｉｏｎ ｆｅａｔｕｒｅ ａｎｄ ｉｄｅｎｔｉｆｉｃａｔｉｏｎ ｍｅｔｈｏｄｓ ｏｆ ｇａｓ ｔｕｒｂｉｎｅ ｒｏｔｏｒ ｂｌａｄｅ ｆｒａｃｔｕｒｅ ｆａｕｌｔ[Ｊ]. Ｊｏｕｒｎａｌ ｏｆ Ｍｅ￣ｃｈａｎｉｃａｌ ＆ Ｅｌｅｃｔｒｉｃａｌ Ｅｎｇｉｎｅｅｒｉｎｇ， ２０２１，３８(８):９３５ －９４３.