Patent ID: 11860066
Assignee: XI'AN JIAOTONG UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC G  F | IPC F  G

Claim 7:
8. A measuring system for implementing the method according to claim 7, comprising:
the blade tip timing sensors configured to be arranged on a rotor blade casing;
a blade tip timing vibration measuring module connected with the blade tip timing sensors so as to measure circumferential blade tip multimodal vibration signals of a rotor blade; and
a calculation unit connected with the blade tip timing vibration measuring module, and the calculation unit comprising:
a modal analysis module configured to perform modal analysis based on a three-dimensional finite element model of a to-be-measured rotor blade so as to acquire a displacement modal shape ϕi of first nm order modal frequency fi of the rotor blade and construct a full-field strain modal matrix ψ=[ψ1,ψ2, . . . ,ψnm] of the rotor blade;
a measuring point optimization module configured to optimize the number of measuring points of the blade tip timing sensors arranged on the rotor blade, wherein a measuring point selection matrix Sbtt arranged in the circumferential direction of the blade tip timing sensor casing under multimodal excitation is constructed, a position where a rotating speed sensor is located serves as a reference 0°, a limited mounting angle range of the casing is removed, and nbtt angles are randomly selected in the circumferential direction of the casing to serve as mounting positions of the blade tip timing sensors; and the condition number κ of the blade tip timing measuring point selection matrix Sbtt is calculated, a random process is repeated for R times, and a measuring point layout when the condition number κ of the matrix is minimum is selected therefrom;
a conversion matrix calculation module configured to construct a conversion matrix of single-point displacement and full-field dynamic strains of the blade; and
a strain field reconstruction module configured to calculate positive strains and shearing strains of all nodes on the surface of and inside the blade at each turn of the rotor blade.