seismic behavior evaluation of semi-rigid steel frames with t-stub connections under nonlinear analysis

 the high energy applied and movements of plus shape in less time by the near fault earthquake, which causes brittle fracture in rigid connections that during the northridge 1994 and kobe1995 earthquakes was frequently seen. semi-rigid connections behavior can be shaped and have a good ability to absorb energy.the use of semi-rigid connections in structure with more stories, provided on the drifts control can be appropriate. in the frame with semi-rigid connections, because of that the rigidity of connections is less than the beams and columns, with suitable energy absorption and rotation is causing tensions in the beams and columns become low. the purpose of this paper is analysis and compares the behaviors of rigid and t-stub semi-rigid connections in steel frame moment with nonlinear time history analysis. in order to four frame with lateral loading systems and ordinary steel frame with number stories 3,6,9,12 according to ubc97 regulation designed to consider in two state, rigid and semi rigid connection. the results show that t-stub semi-rigid connections decreases the lateral drift and increase the frame stability against lateral loading.