چكيده به لاتين
In this study, the seismic performance assessment of steel moment-resisting frames under far and near fault records given in the appendix of FEMA P695 with and without viscous dampers in linear and nonlinear states was investigated by using FEMA P695. The 4,8, 12 and 16-story frames are loaded, analyzed and designed in two modes with and without damper based on ASCE 7-10 and AISC 360 as well as linear viscous damper specifications with damping exponent (α = 1) and nonlinear viscous damping exponent (α = 0.5), (α = 0.2) were considered for a specific damping coefficient of 20% (4 and 8 –story model) and 25% (12 and 16-story model) by using energy methods based on ASCE 7-10. Frames with and without dampers are modeled by placing concentrated plastic hings with Bilin cyclic behavior in OpenSees software. These frames were analyzed and investigated with incremental dynamic analysis method (IDA) by using 44 far-fault records and 28 near-fault records with pulse scaled over a wide range of seismic intensity values using the Hunt&Fill algorithm and analyzed. Seismic performance assessment of the studied frames are presented as probability of collapse based on analysis seismic fragility probabilities. The results show that in steel moment-resisting frames with linear viscous dampers at 50% probability of collapse and the standard deviation of the natural logarithm of the values of incremental dynamic analysis, the collapsed capacity of 4,8, 12 and 16-story frames were increased to 54%, 88%, 74%, 57% for far-fault records and to 55%, 76%, 72%, 64% for near-fault records, respectively. It is also shown that structures with linear viscous dampers have shown better seismic behavior in collapse than the structures with non-linear viscous dampers, while at the Immidiate Occupancy and life safety of performance, the nonlinear dampers have better performance in earthquake energy absorption than linear dampers.
