Experimental study on damage detection of base-isolated structure using an adaptive extended Kalman filter

In this paper, experimental studies are performed and presented to verify the capability of the adaptive extended Kalman filter (AEKF) approach for identifying and tracking damages in nonlinear structures. A base-isolated building model consisting of a scaled building model mounted on a rubber-bearing isolation system has been tested experimentally in the laboratory. The non-linear behavior of the base isolators is represented by the Bouc-Wen model. To simulate the structural damages during the test, an innovative device, referred to as the stiffness element device (SED), is proposed to reduce the stiffness of the upper storey of the structure. Various damage scenarios have been simulated and tested. The measured acceleration response data and the AEKF approach are used to track the variation of the stiffness during the test. The tracking results for the stiffness variations correlate well with that of the referenced values. It is concluded that the AEKF approach is capable of tracking the variation of structural parameters leading to the detection of damages in nonlinear structures.