Comparison of Approximate and Exact Methods of Incremental Dynamic Analysis in Seismic Evaluation of Steel Moment Resisting Frames

In recent years، different kinds of nonlinear static and dynamic analysis have been developed for the seismic evaluation of structures. Most of the nonlinear and dynamic methods not only need great volume of calculations and are very time consuming، but also there is a need for a proper skill and proficiency in order to analyze the results. For this reason، numerous approximations and simplifications in nonlinear static methods have been applied which reduce the precision of the results. In the evaluation of the structures based on performance، the speed and precision of conducting different analyses are very significant criteria. This issue has led to the creation of various new methods based on the principles of nonlinear and incremental static and dynamic analysis. In this study، the capabilities and limitations of Modal Incremental Dynamic Analysis (MIDA) and Incremental Modified Pushover (IMP) analysis methods have been evaluated. For this purpose، three models of 3، 9 and 12 story steel moment resisting frames have been analyzed with DRAIN-2DX code. Results of the analysis methods chosen in this paper for predicting of the seismic behavior of buildings are compared with those of dynamic analysis.