چكيده به لاتين
In seismic regions of the world, the structural designers in addition to considering life safety, they also pay special attention to economic aspects of the design regarding to operation levels. So in order to meet all of the mentioned desired objects, the linked column frame system (LCF) was innovated by Dusicka [1] in 2007. In this system, the steel frame is made up of two main parts including dual columns which interconnected together with replaceable links and a secondary flexible moment frame. The links in LCF systems operate as a fuse which protect the other members of the system from damage following a moderate earthquake, they are also replaceable to return the building to occupancy operation level rapidly. In this thesis, seismic operation of LCF systems by considering variations in height of structure and length of links toward fragility estimation were studied. For this purpose, 17 specimens of 3-story, 6-story and 9-story LCF buildings were designed according to the authentic codes, then 2D linked column frames were modeled nonlinearly and analyzed using incremental dynamic analysis (IDA) under 14 ground motion records which consist of Far-Field and Near-Field ground motion according to FEMA P695. Next fragility curves of the sample frames were achieved using IDA data in IO, LS and CP operation levels. Comparison of the fragility curves shows that in the taller frames the longest links with shear operation have the least probability of failure. Finally, three samples of 3-story, 6-story and 9-story SMF structures were designed, modeled and then compared with LCF specimens toward fragility estimation and the conclusions show that LCF structures have better seismic behavior versus SMF structures.
