Rotor blade modal detection method based on rotation state

The invention belongs to the field of aero-engines, and discloses a rotor blade modal detection method based on a rotation state, and the method comprises the steps: building a modal test system of a to-be-detected rotor blade; a plurality of measuring points are selected for the to-be-measured rotor blade and the reflectors are pasted; rotating speed matching is carried out, so that the to-be-measured rotor blade and the image anti-rotating mechanism rotate respectively; the laser Doppler measurement system outputs a laser beam, one laser beam is irradiated to the to-be-measured rotor blade after passing through the image reverse rotation mechanism and acts with the other laser beam after being reflected by the to-be-measured rotor blade to obtain a vibration signal, namely, a modal vibration signal of each measurement point; the modal vibration signals of all the measuring points are input into modal analysis software, modal analysis is carried out, multi-order modal parameters of the to-be-measured rotor b