Damage Assessment Using Natural Frequency on Concentric Braced Frame Steel Structures

At present, structural assessment using dynamic characteristics remains to be explored. In this study, a correlation between damage index and natural frequencies of Concentric Braced Frame steel structures has been observed. The study consists of two sections: The first section presents the calculation of the damage indices of structures by means of monotonic and semicyclic pushover analyses using OpenSEES software, while the second section evaluates the structures' natural frequencies by means of modal analyses using SAP2000 software. Our results show a trend in which with increasing amounts of lateral load, natural frequencies of the structures decrease while the damage indices increase. There is also an apparent 'jump' in the damage index values after the lateral loads reach their critical limits. The study results help the understanding of the structural assessment process at the global scale.