Damage detection of a steel frame subjected to ground motion

In this paper are presented the results of an experimental study concerning the dynamic identification and the damage assessment of a four-story steel frame tested at the Carlton Laboratory of the Department of Civil Engineering and Engineering Mechanics at the Columbia University in New York. The dynamic identification is, first, performed through the EFDD (Enhanced Frequency Domain Decomposition) method by using only the output records according to the Operational Modal Analysis. Then, the OKID-ERA/DC time domain algorithm is applied as well, using the output accelerations together with the input recorded signal. One damage scenario is considered and various linear damage indexes, based on the use of two records (in the undamaged and damaged states, respectively), are applied to estimate the presence and the location of damage. The main goal of this investigation is to obtain some useful indications about the efficacy of the analyzed identification techniques and damage indexes.