GLOBAL DAMAGE IDENTIFICATION OF THE ‘STEELQUAKE’ STRUCTURE USING MODAL DATA

Abstract

This paper deals with the important question of structural safety after extreme loadings like an earthquake. The structure investigated here is the so-called ‘Steelquake’ benchmark structure, a two-storey building which was subjected by an artificial seismic loading causing cracks at three locations. The aim of the method is the identification of multiple damage. It is based on the changes of the measured eigenfrequencies and normal modes before and after the pseudo-seismic event. The measured changes of the modal quantities and the physical structural changes are linked together by means of a computational model. This leads to an inverse problem. Four different model-based approaches are discussed and applied to the benchmark structure. The ability of these approaches to find the damage is investigated and it is shown that all three cracks could be identified.