An extended Kalman Filter procedure for damage detection of base-isolated structures

Base isolation is widely adopted to mitigate earthquake effects on structures. Information concerning the status of the isolation devices is fundamental, for example, after an emergency event and, consequently, damage detection procedures have received significant attention in the recent years. Herein, an extended Kalman filter approach is developed for real-time estimation of the isolation device stiffness from acceleration measurements. Simulations have been carried out by means of a three degree of freedom model and results are illustrated. Moreover, experimental evaluations of the damage detection method have been conducted by means of a prototype structure that has been excited adopting a sequence of seismic events. The results highlight a stiffness degradation and fully agree with the measurements, allowing a validation of the technique.