Identification method of foreign object impact on blade based on blade tip timing

Foreign Object Impact（FOI）is an important event that affects the safe operation of blades, and the online identification of FOI events is conducive to the early warning of huge disasters. To solve the urgent need of a large amount of vibration data during the service of the blade and the need to quickly and accurately identify the FOI event online, a method for the identification of FOI events and the location of the impact moment of the blade under multiple working conditions is proposed, using the joint criterion of Kurtosis and Amplitude Moment（KAM-BTT）. This method is based on the blade tip timing method, and requires only a single sensor. In this paper, a foreign object impact vibration response model considering the blade installation error, blade detuning and sensor installation error is constructed, the FOI simulation is carried out, and a method for obtaining the threshold of foreign object impact identification parameters based on the blade model parameters is proposed. The experimental device for FOI was set up, and the verification of FOI identification at multiple speeds was completed. Experimental results show that the KAM-BTT method proposed in this paper can realize the identification of FOI events within 0.047 s with a single sensor, which provides a research basis for online early warning and data management.