Set-membership identification technique for structural damage based on the dynamic responses with noises

Abstract

SUMMARYBased on the availability of measured acceleration signals of structures, the interval analysis technique and setmembership identification concept are combined to identify the structural damage in this paper. Because of the insufficiency and uncertainty of information obtained from measurements, the noises of measurements are enveloped by interval numbers. Via the first-order Taylor series expansion, the interval bounds of the element stiffness parameters (ESPs) of both undamaged and damaged structures are derived by updating the reference finite element model. Through the intersection operations of intervals of the ESP obtained from dynamic responses in different time periods, the estimate intervals of the ESP are refined. Three damage indexes as stiffness reduce factor, possibility of damage existence, and damage measure index are introduced to identify the damage in the structure. Even though the dynamic responses are with low signal-to-noise ratio, the injury of structure can be detected by the proposed method. Two numerical examples and an experimental example are performed to demonstrate the feasibility and effectiveness of the proposed technique. The results show that the proposed method can improve the accuracy of damage diagnosis compared with the deterministic damage identification method.

A nonprobabilistic structural damage identification approach based on orthogonal polynomial expansion and interval mathematics

“…In the following part, a test has been implemented to further verify the presented method. A four‐story shear frame structure is used as an experimental example. The diagrammatic sketch of the four‐story shear frame structure is shown in Figure a.…”