Damage identification of isolators in base-isolated torsionallycoupled buildings

Abstract

This paper deals with the damage assessment for isolators of base-isolated building systemsconsidering the torsion-coupling (TC) effect by establishing damage indices. The damage indices canindicate the reduction in lateral stiffness of the isolator story as explicit formulas in terms of modalparameters. In addition, the damage location, expressed in terms of the estimated damage index andeccentricities before and after damage, is also presented. Numerical analysis shows that the proposedalgorithms are applicable for general base-isolated multi-story TC buildings. A procedure from the analysisof seismic response to the implementation of damage indices is demonstrated by using a numerical case. Asystem identification technique is employed to extract modal parameters from seismic responses of abuilding. Results show that the proposed indices are capable of detecting the occurrence of damage andpreliminarily estimating the location of damaged isolator