MEASUREMENT METHOD FOR ROTOR BLADE DYNAMIC STRAIN FIELD BASED ON BLADE TIP TIMING AND SYSTEM THEREOF

摘要

Disclosed are a measurement method for rotor blade (4) dynamic strain field based on blade tip timing and a system thereof. The method comprises the following steps: establishing a three-dimensional finite element model of the rotor blade (4) to be measured, and extracting modal parameters of the three-dimensional finite element model (S1); determining the number and circumferential installation positions of blade tip timing sensors (1) (S2); establishing a mapping relationship between blade single-point displacement and full-field dynamic strain (S3); obtaining blade tip single-point displacement of the rotor blade (4) based on the blade tip timing sensor (1) (S4); and obtaining the dynamic strain measurement of the rotor blade (4) at arbitrary position and in arbitrary direction according to the single-point displacement based on the mapping relationship (S5). The method only uses finite measure points of the blade tip to realize the reconstruction of the overall dynamic strain field of the rotor blade (4), and can achieve the measurement of the normal strain and the shear strain of all the nodes on the surface and in the interior of the rotor blade (4) under multi-modal vibration. The calculation process is simple, and online measurement can be easily carried out.