doi:10.3850/978-981-08-7619-7_P034

ABSTRACT

An early detection of structural damage is an important goal of any structural health monitoring system. In particular, the ability to detect damages, either on-line or almost on-line, based on vibration data measured from sensors, is essential for the structural health monitoring system. The problem is quite challenging, in particular when the external excitations are not completely measured and when the structural system is nonlinear. In practical applications, external excitations (inputs), such as seismic excitations, wind loads, traffic loads, etc., may not be measured or may not be measurable, and the structure may not always be linear. In this paper, a newly proposed damage detection method, referred to as the adaptive quadratic sum-squares error with unknown inputs (AQSSE-UI), is used for the detection of structural damages of a nonlinear hysteretic structure. In this approach, external excitations and some structural responses may not be measured. The accuracy and effectiveness of the proposed approach will be demonstrated by numerical simulations with or without the measurement of external excitations. The simulation results indicate that the proposed damage detection technique is capable of identifying structural parameters, tracking the changes of parameters leading to the detection of structural damages, as well as predicting the unknown external excitations.

Keywords:Structural Health Monitoring, Adaptive Quadratic Sum-Squares Error with Unknown Inputs, Adaptive Tracking, System Identification, Damage Detection, Nonlinear Structure.

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