Investigating the Seismic Performance of Steel Moment-Resisting Frames by Using Damage Index

In the seismic analysis of structures, estimation of amount of damages to the elements is of great importance. In the quantitative method of estimating damages, it is possible to assess damages to the storey and the total structure by introducing damage indices. The results of studies show that damage indices could be used as a suitable basis in assessing the function of structure against back and forth forces of earthquake excitations. These indices are calculated based on functions of deformation, and dissipated energy of elements in frames. In this study, the steel moment-resisting frames with 4, 7, 10, 15, 20, and 25-story and 3 and 5 bays are designed and then, they are modeled in OpenSees software in order to investigate the performance of steel moment-resisting frames under seismic excitations by using damage index. In the following, nonlinear dynamic time history analysis is conducted and the damages of aforementioned frames are calculated quantitatively and the results showed that the behavior of high-rise, mid-rise, and low-rise frames were affected based on their vibration periods and dependent to the nature of the studied earthquakes.