Application of model-based damage identification to a seismically loaded structure

The aim of the presented model-based damage identification approach is to detect, localize and quantify changes in a mechanical structure due to damage by means of a computational model and measured changes of the structure's dynamic behavior. An inverse sensitivity problem is formulated, leading to a large number of damage parameters when the structure has many structural members. While the number of potential candidates for the damage locations is very large, usually there are only very few active parameters concentrating on the damaged areas. It turns out that the parameter subset selection is an essential step. The method is applied to a large scale structure, the so-called Steelquake structure, a two-storey building, which was subjected to a seismic loading. Cracks at different locations developed during this loading. All crack locations are successfully identified by the algorithm, but one undamaged position was also localized. Additional simulation studies show that errors in the measurement data can cause a false indication of damage.