INVESTIGATION OF FORWARD DIRECTIVITY EFFECT ON THE DUCTILITY DEMAND AND REDUCTION FACTOR OF PBPD EBF FRAMES

Structures designed by current seismic codes usually undergo large deformations on severe earthquakes because in this codes the design procedure is based on elastic analysis and the inelastic states are considered indirectly. These problems lead researchers to new design methods which provide a higher level of performance, safety and economy. To achieve this aims, parameters like lateral force, strength of members, desired yield mechanism and etc., should be considered in designing procedure initially. One of this new methods is Performance-Based Plastic Design (PBPD). Results of numerous inelastic static and dynamic analysis performed by the researchers on the structures designed by this method show a high level of performance. This study aims to investigate the effect of forward directivity as one the significant characteristics of near-fault records on the inelastic response of EBF structures designed based on PBPD method in the form of changes in the ductility demand (μ) and reduction factor (Rμ). To achieve this goal, two 12- and 18-story Eccentrically Braced Frames were designed by current seismic code and then the same frames were designed by PBPD method. In all frames, changes of these two parameters were investigated, the results show that the calculated values of this parameters are different from Newmark’s equations and also from results of records without the forward directivity effect.

کلیدواژه ها:

DFC Connection ، Reduced Beam Section ، Ductility ، Moment resisting