Damage assessment of moment resisting frame structures using corelation between damage index and natural frequency

Damage index is a define scale to describe damage of the structure due to earthquake. Several studies of damage index have been carried out on reinforced structures, but not many studies performed on steel structures. Numerical research about damage index on moment resisting frame of steel structure has been conducted. Monotonic and semi-cyclic pushover analyses using OpenSEES software was carried out to obtain the index. Two paramaters that affect the damage index value are the displacement ratio and energy absorbsion. Damage index value of MRF obtained in this research is governed by the displacement ratio. The main objective of this study is to correlate damage index and the natural frequency. SAP2000 is used to get the natural frequency through modal analysis. The results show that natural frequency can be used to assess structural damage. Hence, structural health monitoring can be simplied by assesing the natural frequency.