ﺑﺮرﺳﯽ ﺗﺎﺛﯿﺮ ﻋﺪم ﻗﻄﻌﯿﺖ ﭘﺎراﻣﺘﺮﻫﺎي ﻣﺪل اﯾﺒﺎر- ﻣﺪﯾﻨﺎ-ﮐﺮاوﯾﻨﮑﻠﺮ ﺑﺮ ﻇﺮﻓﯿﺖ ﻓﺮورﯾﺰش ﻟﺮزه اي ﻗﺎب ﻫﺎي ﺧﻤﺸﯽ ﻓﻮﻻدي

Investigation of the Effect of Uncertainty of the Ibara-Madina-krawinkler Model Parameters on Seismic Collapse Capacity in Steel Moment Resisting Frames

ﮔﺮﭼﻪ ﻓﺮورﯾﺰش ﮐﻠﯽ ﺳﺎﺧﺘﻤﺎن ﻫﺎ ﺗﺤﺖ زﻟﺰﻟﻪ ﮐﻤﺘﺮ اﺗﻔﺎق ﻣﯽ اﻓﺘﺪ اﻣﺎ رﺧﺪاد اﯾﻦ ﺣﺎدﺛﻪ در دﻫﻪ ﻫﺎي اﺧﯿﺮ و اﻣﮑﺎن ﺗﮑﺮار آن در آﯾﻨﺪه، ﺗﺤﻘﯿﻖ در اﯾﻦ زﻣﯿﻨﻪ را اﺟﺘﻨﺎب ﻧﺎﭘﺬﯾﺮ ﻧﻤﻮده اﺳﺖ. ﻣﻄﺎﻟﻌﺎت ﻋﺪدي و آزﻣﺎﯾﺸﮕﺎﻫﯽ ﻣﺨﺘﻠﻔﯽ در زﻣﯿﻨﻪ ي ﻓﺮورﯾﺰش ﻟﺮزه اي ﺳﺎزه ﻫﺎ ﺻﻮرت ﮔﺮﻓﺘﻪ اﺳﺖ. از راﯾﺞ ﺗﺮﯾﻦ ﻣﺪﻟﻬﺎﺋﯽ ﮐﻪ زوال ﻣﻘﺎوﻣﺖ و ﺳﺨﺘﯽ اﻟﻤﺎﻧﻬﺎي ﺳﺎزه ﺗﺤﺖ زﻟﺰﻟﻪ را در ﻧﻈﺮ ﻣﯽ ﮔﯿﺮد، ﻣﺪل رﻓﺘﺎري ﺳﻪ ﺧﻄﯽ اﯾﺒﺎرا- ﻣﺪﯾﻨﺎ- ﮐﺮاوﯾﻨﮑﻠﺮ ﻣﯽ ﺑﺎﺷﺪ ﮐﻪ در ﻣﻮرد ﺳﺎزه ﻫﺎي ﻓﻮﻻدي، ﭘﺎراﻣﺘﺮﻫﺎي آن ﺗﻮﺳﻂ ﻣﺤﻘﻘﯿﻦ دﯾﮕﺮ ﺑﺎ اﻧﺠﺎم ﺗﻌﺪاد زﯾﺎد ﺗﺴﺘﻬﺎي اﺗﺼﺎﻻت آزﻣﺎﯾﺸﮕﺎﻫﯽ اراﺋﻪ ﺷﺪه اﺳﺖ. ﻣﺪﻟﻬﺎي رﻓﺘﺎري ﺣﺎﺻﻞ از ﺗﺴﺘﻬﺎي آزﻣﺎﯾﺸﮕﺎﻫﯽ ﻣﻌﻤﻮﻻ ﺑﺎ ﺑﺮازش ﯾﮏ ﻣﺪل رﯾﺎﺿﯽ ﻫﻤﺮاه اﺳﺖ و ﺧﻄﺎﻫﺎي زﯾﺎدي دارد، ﺑﻪ ﻋﺒﺎرﺗﯽ وﺟﻮد ﻋﺪم ﻗﻄﻌﯿﺖ در ﻣﺪل ﻫﺎي رﻓﺘﺎري آزﻣﺎﯾﺸﮕﺎﻫﯽ از ﭼﺎﻟﺶ ﻫﺎي اﺳﺎﺳﯽ ﮐﺎرﺑﺮد ﻋﻤﻠﯽ آﻧﻬﺎﺳﺖ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﯾﮏ ﺳﺎزه ي 5 ﻃﺒﻘﻪ ي ﻓﻮﻻدي ﺑﺎ ﺳﯿﺴﺘﻢ ﻫﺎي ﻗﺎب ﺧﻤﺸﯽ ﻣﺘﻮﺳﻂ ﻣﻄﺎﺑﻖ ﺿﻮاﺑﻂ آﺋﯿﻦ ﻧﺎﻣﻪ ﻫﺎي داﺧﻠﯽ ﻃﺮاﺣﯽ ﺷﺪه اﺳﺖ. اﺛﺮ ﮐﺎﻫﻨﺪﮔﯽ ﻣﻘﺎوﻣﺖ و ﺳﺨﺘﯽ اﻟﻤﺎﻧﻬﺎي ﺳﺎزه ﺑﺮ اﺳﺎس ﻣﺪل رﻓﺘﺎري اﯾﺒﺎرا-ﻣﺪﯾﻨﺎ-ﮐﺮاوﯾﻨﮑﻠﺮ اﻋﻤﺎل ﺷﺪه اﺳﺖ. ﺗﺤﻠﯿﻞ ﻫﺎي دﯾﻨﺎﻣﯿﮑﯽ اﻓﺰاﯾﻨﺪه ﺗﺤﺖ50 زوج ﺷﺘﺎﺑﻨﮕﺎﺷﺖ ﭘﯿﺸﻨﻬﺎدي دﺳﺘﻮراﻟﻌﻤﻞFEMA P 695 اﻧﺠﺎم ﺷﺪه اﺳﺖ و ﻣﻨﺤﻨﯽ ﻫﺎي ﺷﮑﻨﻨﺪﮔﯽ ﻇﺮﻓﯿﺖ ﻫﺎي ﻓﺮورﯾﺰش ﺑﺎ در ﻧﻈﺮ ﮔﺮﻓﺘﻦ ﻋﺪم ﻗﻄﻌﯿﺖ در ﻟﻨﮕﺮ ﺗﺴﻠﯿﻢ و ﻟﻨﮕﺮ اوج اﻟﻤﺎﻧﻬﺎ و ﻇﺮﻓﯿﺖ دوران ﻧﻬﺎﺋﯽ اﻟﻤﺎﻧﻬﺎ ﺗﻮﺳﻌﻪ داده ﺷﺪه اﺳﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽ دﻫﺪ، ﺑﯿﻦ ﭘﺎراﻣﺘﺮﻫﺎي ﻣﻮرد ﺑﺮرﺳﯽ، ﻋﺪم ﻗﻄﻌﯿﺖ در ﭘﺎراﻣﺘﺮ ﻟﻨﮕﺮ اوج ﺑﯿﺸﺘﺮﯾﻦ ﺗﺎﺛﯿﺮ را ﺑﺮ ﻇﺮﻓﯿﺖ ﻓﺮورﯾﺰش ﺳﺎزه ﻣﯽ ﮔﺬارد و ﻣﯽ ﺗﻮاﻧﺪ ﺗﺎ 19,2 درﺻﺪ ﻣﯽ ﺗﻮاﻧﺪ اﺣﺘﻤﺎل ﻓﺮورﯾﺰش را ﺗﻐﯿﯿﺮ دﻫﺪ. ﻋﺪم ﻗﻄﻌﯿﺖ ﻇﺮﻓﯿﺖ دوران ﻧﻬﺎﺋﯽ ﻧﯿﺰ در ﻣﻘﺎﯾﺴﻪ ﺑﺎ ﭘﺎراﻣﺘﺮﻫﺎي دﯾﮕﺮ ﻧﻘﺶ ﮐﻤﺘﺮي در ﻇﺮﻓﯿﺖ ﻓﺮورﯾﺰش ﺳﺎزه داﺷﺘﻪ اﺳﺖ و ﺗﺎ 5,2 درﺻﺪ اﺣﺘﻤﺎل ﻓﺮورﯾﺰش را ﺗﻐﯿﯿﺮ داده اﺳﺖ.

Although the total collapse of buildings under earthquake occurs less but the incidence in recent decades and the possibility of its re-occurrence in the future has made research inevitable in this field. Several numerical and laboratory studies have been carried out on the seismic collapse of the structures. The most common model considering the strength and stiffness deterioration of the structural elements under earthquake is the Ibarra-Madina-Krawinkler three-linear behavioral model that in the case of steel structures, its parameters is presented via performing a large number of laboratory connection tests by the other researchers.The behavioral models resulted from laboratory tests are usually accompanied by a fitting mathematical model with many errors, i.e., the existence of uncertainty in laboratory behavior models is the fundamental challenge of their practical application. In this research, a 5-story steel structure has been designed with intermediate moment resisting frame in accordance with the internal codes. The effect of strength and stiffness deterioration of structural elements is performed based on the Ibara-Madina-Krawinkler behavioral model. Incremental dynamic analysis was carried out under the proposed 50 pairs of earthquake records proposing FEMA P 695 instruction and the fragility curves of its collapse capacities have been developed considering the uncertainty in the yielding moment and the capping moment of the elements and the ultimate rotation capacity of the elements. The results show that among the studied parameters, the uncertainty in the capping moment parameter has the greatest effect on structural collapse capacity and it can change to 19.2% the collapse probability. Uncertainty of the ultimate rotation capacity compared to the other parameters played a small role in structural collapse capacity and has changed the collapse probability up to 5.2 %.