SENSOR PLACEMENT METHOD FOR REDUCING UNCERTAINTY OF STRUCTURAL MODAL IDENTIFICATION

摘要

Sensor placement for structural health monitoring and sensor placement method for reducing uncertainty of structural modal identification. Influences of structural model error and measurement noise on measured responses are separated. Structural stiffness variation is used as model error, and Gaussian noise is used as measurement noise. Monte Carlo method simulates a large number of possible cases, and structural mode shape matrices under each model error condition are obtained. Conditional information entropy index quantifies and calculates uncertainty of identified modal parameter results. Conditional information entropy index solves the problem of uncertain Fisher information matrix, which cannot be solved by traditional information entropy method. Optimal sensor placement corresponds to maximum conditional information entropy index value. The sensor placement method considers influences of structural model error and measurement noise on structural modal identification, which is helpful for improving accuracy of structural modal parameter identification.