نمود تحليلي پالسهاي سرعت بر رفتار لرزهاي سيستم ميان مرتبه تركيبي قاب خمشي فولادي و پانلهاي مهاربندي واگرا

Analytical Aspects of Velocity Pulses on Seismic Behaviour of Mid-Rise Compound Skeleton of Steel Moment Frame and Eccentrically Braced Panels

ﺳﺎزهﻫﺎي ﺗﺮﮐﯿﺒﯽ ﻗﺎب ﺧﻤﺸﯽ ﻓﻮﻻدي و ﭘﺎﻧﻞﻫﺎي ﻣﻬﺎرﺑﻨﺪيﺷﺪه ﺑﻪ دﻟﯿﻞ ﺷﮑﻞﭘﺬﯾﺮي ﻣﻨﺎﺳﺐ در ﮐﻨﺎر ﺳﺨﺘﯽ ﺑﺎﻻ ﺟﻬﺖ ﻣﻘﺎﺑﻠﻪ ﺑﺎ ﻧﯿﺮوﻫﺎي ﺑﺰرگ دﯾﻨﺎﻣﯿﮑﯽ ﻧﺎﺷﯽ از زﻟﺰﻟﻪﻫﺎ، ﺳﯿﺴﺘﻤﯽ ﻣﻨﺎﺳﺐ ﺑﺮاي ﺳﺎزهﻫﺎي ﻣﯿﺎن ﻣﺮﺗﺒﻪ ﻣﯽﺑﺎﺷﻨﺪ. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺧﺼﻮﺻﯿﺎت رﻓﺘﺎر ﻟﺮزهاي دو ﺳﺎزه 10 ﻃﺒﻘﻪ ﺑﺎ ﺳﯿﺴﺘﻢ ﺗﺮﮐﯿﺒﯽ ﻗﺎب ﺧﻤﺸﯽ-ﭘﺎﻧﻞﻫﺎي ﻣﻬﺎرﺑﻨﺪي واﮔﺮا و ﻗﺎب ﺧﻤﺸﯽ-ﭘﺎﻧﻞﻫﺎي ﻣﻬﺎرﺑﻨﺪي واﮔﺮاي زﯾﭗدار ﺗﺤﺖ اﺛﺮ زﻣﯿﻦﻟﺮزهﻫﺎي ﻗﺪرﺗﻤﻨﺪ ﺣﻮزه ﻧﺰدﯾﮏ ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. اﻧﺪازه و ﺗﻐﯿﯿﺮات ﭘﺎراﻣﺘﺮﻫﺎي ﭘﺎﺳﺦ ﻟﺮزهاي ﻣﺪلﻫﺎي ﻣﻄﺎﻟﻌﺎﺗﯽ ﺑﺮ ﭘﺎﯾﻪ اﻧﺠﺎم ﺗﺤﻠﯿﻞﻫﺎي ﻏﯿﺮ ﺧﻄﯽ ﺗﺎرﯾﺨﭽﻪ زﻣﺎﻧﯽ ﻣﺤﺎﺳﺒﻪ ﮔﺮدﯾﺪه اﺳﺖ. ﻣﺪلﻫﺎي ﻣﻄﺎﻟﻌﺎﺗﯽ ﻣﻄﺎﺑﻖ ﺑﺎ ﺿﻮاﺑﻂ ﻃﺮح ﻟﺮزهاي وﯾﺮاﯾﺶ ﭼﻬﺎرم آﯾﯿﻦﻧﺎﻣﻪ 2800 و ﻣﺒﺎﺣﺚ ﺷﺸﻢ و دﻫﻢ ﻣﻘﺮرات ﻣﻠﯽ ﺳﺎﺧﺘﻤﺎن ﻃﺮاﺣﯽ ﺷﺪهاﻧﺪ. ﺑﺮ ﭘﺎﯾﻪ ﻧﺘﺎﯾﺞ اﯾﻦ ﭘﮋوﻫﺶ؛ داﻧﺴﺘﻪ ﺷﺪه ﮐﻪ وﺟﻮد ﭘﺎﻟﺲﻫﺎي ﺑﺰرگ و ﭘﯿﻮﺳﺘﻪ در ﺗﺎرﯾﺨﭽﻪ زﻣﺎﻧﯽ زﻟﺰﻟﻪﻫﺎي ﻧﯿﺮوﻣﻨﺪ، ﭘﺎراﻣﺘﺮﻫﺎي ﭘﺎﺳﺦ ﺳﺎزه را ﺑﻪ ﺷﺪت ﺗﺤﺖ ﺗﺄﺛﯿﺮ ﻗﺮار ﻣﯽدﻫﺪ. ﺳﺎﺧﺘﺎر ﻣﻄﺎﻟﻌﺎﺗﯽ اﯾﻦ ﭘﮋوﻫﺶ درﺑﺮﮔﯿﺮﻧﺪه روﻧﺪ ﺗﺤﻠﯿﻠﯽ ﻣﺮﺑﻮط ﺑﻪ ﻧﻤﻮدارﻫﺎي ﭘﻮش ﺑﯿﺸﯿﻨﻪ درﯾﻔﺖ، ﺷﺘﺎب و ﺳﺮﻋﺖ ﻃﺒﻘﺎت ﺳﺎزهﻫﺎي ﻣﻄﺎﻟﻌﺎﺗﯽ و ﻫﻤﭽﻨﯿﻦ ﺗﺎرﯾﺨﭽﻪ زﻣﺎﻧﯽ درﯾﻔﺖ ﻃﺒﻘﺎت و ﻧﯿﺮوي ﻣﺤﻮري ﺳﺘﻮنﻫﺎ اﺳﺖ. ﻧﻤﻮدارﻫﺎي ﺗﺎرﯾﺨﭽﻪ زﻣﺎﻧﯽ درﯾﻔﺖ ﻃﺒﻘﺎت، ﻫﻢ ارز ﺑﻮدن ﺗﻐﯿﯿﺮات ﻧﺎﮔﻬﺎﻧﯽ اﯾﻦ ﭘﺎراﻣﺘﺮ ﺑﺎ ﭘﺎﻟﺲ اﺻﻠﯽ ﺳﺮﻋﺖ را ﻧﺸﺎن ﻣﯽدﻫﺪ. ﺑﺮرﺳﯽ ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ ﻋﻼوه ﺑﺮ وﺟﻮد ﭘﯿﭽﯿﺪﮔﯽ ﺗﻮﺻﯿﻔﯽ در ﭘﺎﺳﺦﻫﺎ، ﻧﯿﺎزﻫﺎي ﻟﺮزهاي ﺗﺤﺖ رﮐﻮردﻫﺎي ﺣﻮزه ﻧﺰدﯾﮏ ﮔﺴﻞ، داراي ﻧﻤﻮد ﺑﻪ ﻣﺮاﺗﺐ ﺑﺰرگﺗﺮي ﻧﺴﺒﺖ ﺑﻪ رﮐﻮردﻫﺎي دور از ﮔﺴﻞ ﻣﯽﺑﺎﺷﺪ. روﻧﺪ ﺗﺸﮑﯿﻞ ﻣﻔﺎﺻﻞ ﭘﻼﺳﺘﯿﮏ از ﻧﻈﺮ ﻧﻮع و ﻣﺤﻞ، ﺑﺴﺘﻪ ﺑﻪ ﻋﻤﻠﮑﺮد ﺳﯿﺴﺘﻢ ﻣﻘﺎوم ﺳﺎزهاي، ﺗﺤﺖ ﺗﺄﺛﯿﺮ ﻣﺎﻫﯿﺖ راﻧﺪوم رﮐﻮردﻫﺎي ﻧﯿﺮوﻣﻨﺪ زﻟﺰﻟﻪ ﻗﺮار دارد.

Steel moment frame and bracing panels compound structures are suitable systems for medium-height resistant skeletons due to their desirable ductility along with high rigidity when facing large dynamic forces caused by earthquakes. In this research, the seismic behavior of two 10-story buildings with compound systems of moment frame/eccentrically braced frames as well as moment frame/eccentrically braced frame with zipper elements are evaluated. The evaluation and changes of the seismic response parameters of the studied models are based on performing nonlinear time history analyses. The studied models are designed according to the fourth edition of seismic design provisions in Code 2800, plus the 6th and 10th issues of the Iranian National Building Regulations. Following the results of this research, it has been recognized that the existence of large coherent pulses in the time history of powerful earthquakes affects the response parameters of the building to a great extent. The results of this research includes the analytical process in the graphs related to maximum push of the drift, floors acceleration and velocity of the studied structural models and also the time history of story’s drift and axial force of the columns. The graphs of the story drift show the simultancy of the sudden changes of this parameter with the main velocity pulse. The results show that seismic responses and demands under near-field records have a bigger appearance than the corresponding effects obtained exposed to far-field records. The formation and development of plastic hinges in terms of type and location, based on the performance of resistant structural system, are influenced by the random nature of strong earthquake records.