ﺑﺮرﺳﯽ ﻋﻤﻠﮑﺮد ﻣﯿﺮاﮔﺮ ﺷﮑﺎﻓﺪار و ﺗﯿﺮ ﺑﺎ ﺳﻄﺢ ﻣﻘﻄﻊ ﮐﺎﻫﺶ ﯾﺎﻓﺘﻪ ﺗﺤﺖ ﺑﺎرﮔﺬاري ﭼﺮﺧﻪاي

Evaluation of Slit Steel Damper & Reduced Beam Section Connections Under Cyclic Loading

ﯾﮑﯽ از ﻧﻘﺪﻫﺎي ﻣﻄﺮح ﺷﺪه ﺑﻪ اﺗﺼﺎﻻت ﭘﯿﺸﻨﻬﺎدي ﺑﻌﺪ از زﻟﺰﻟﻪﻫﺎي ﻧﻮرﺛﺮﯾﭻ و ﮐﻮﺑﻪ، ﺗﺨﺮﯾﺐ ﺗﯿﺮ ﺑﻌﺪ از وﻗﻮع زﻟﺰﻟﻪ، دﺷﻮاري و ﻣﻘﺮون ﺑﻪ ﺻﺮﻓﻪ ﻧﺒﻮدن ﺗﻌﻮﯾﺾ آن ﭘﺲ از زﻟﺰﻟﻪ ﻣﯽﺑﺎﺷﺪ. ﺑﻪ ﻫﻤﯿﻦ ﻣﻨﻈﻮر اﯾﺪه اﺳﺘﻔﺎده از اﺗﺼﺎﻻت ﻫﻤﺮاه ﺑﺎ ﻣﯿﺮاﮔﺮ ﺷﮑﺎﻓﺪار )SSD ( ﮐﻪ ﻣﻮﺟﺐ اﺳﺘﻬﻼك اﻧﺮژي و ﺗﺸﮑﯿﻞ ﻣﻔﺼﻞ ﭘﻼﺳﺘﯿﮏ در ﻣﮑﺎﻧﯽ ﻏﯿﺮ از اﻟﻤﺎنﻫﺎي اﺻﻠﯽ ﺳﺎزهاي ﻣﯿﮕﺮدد، ﻣﻄﺮح ﺷﺪ. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ اﺑﺘﺪا ﻣﻘﺎﯾﺴﻪاي ﺑﯿﻦ اﺗﺼﺎل SSD و اﺗﺼﺎل ﺗﯿﺮ ﺑﺎ ﺳﻄﺢ ﻣﻘﻄﻊ ﮐﺎﻫﺶ ﯾﺎﻓﺘﻪ )RBS ( ﺗﺤﺖ ﺑﺎرﮔﺬاري ﭼﺮﺧﻪاي اﻧﺠﺎم ﺷﺪه اﺳﺖ. در اداﻣﻪ ﭘﯿﺸﻨﻬﺎداﺗﯽ ﺑﻪ ﻣﻨﻈﻮر ﺑﻬﺒﻮد ﻋﻤﻠﮑﺮد اﺗﺼﺎل SSD ﺑﺎ ﻗﺎﺑﻠﯿﺖ اﺳﺘﻔﺎده در ﻗﺎبﻫﺎي ﺧﻤﺸﯽ وﯾﮋه ﻣﻄﺮح ﮔﺮدﯾﺪه اﺳﺖ، ﮐﻪ اﯾﻦ ﭘﯿﺸﻨﻬﺎدات ﺷﺎﻣﻞ اﻓﺰاﯾﺶ ﺿﺨﺎﻣﺖ و ﺗﻌﺪاد ﻧﻮارﻫﺎ و ﻫﻤﭽﻨﯿﻦ ﮐﺎﻫﺶ ارﺗﻔﺎع ﻣﯿﺮاﮔﺮ ﺑﻮده اﺳﺖ. ﻧﺘﺎﯾﺞ ﻣﻄﺎﻟﻌﺎت ﻧﺸﺎن داد ﮐﻪ اﺗﺼﺎل SSD از ﻟﺤﺎظ ﻋﻤﻠﮑﺮدي ﺗﻔﺎوت زﯾﺎدي ﺑﺎ اﺗﺼﺎل RBS ﻧﺪاﺷﺘﻪ اﺳﺖ و ﻣﻄﺎﺑﻖ ﺑﺎ ﺿﻮاﺑﻂ ﻟﺮزهاي اﺗﺼﺎﻻت از ﭘﯿﺶ ﺗﺎﯾﯿﺪ ﺷﺪه، اﻣﮑﺎن اﺳﺘﻔﺎده از اﯾﻦ اﺗﺼﺎل در ﻗﺎبﻫﺎي ﺧﻤﺸﯽ وﯾﮋه وﺟﻮد دارد ﺑﺎ اﯾﻦ ﺗﻔﺎوت ﮐﻪ ﻧﯿﺎز ﺑﻪ ﺗﻌﻮﯾﺾ آن ﭘﺲ از زﻟﺰﻟﻪ ﻧﻤﯽﺑﺎﺷﺪ. ﻫﻤﭽﻨﯿﻦ ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ اﻓﺰاﯾﺶ ﺿﺨﺎﻣﺖ و ﮐﺎﻫﺶ ارﺗﻔﺎع ﻣﯿﺮاﮔﺮ ﺑﺮ ﺧﻼف اﻓﺰاﯾﺶ ﺗﻌﺪاد ﻧﻮارﻫﺎي آن، ﺑﺮ روي ﻋﻤﻠﮑﺮد اﺗﺼﺎل SSD ﺗﺎﺛﯿﺮ ﺑﯿﺸﺘﺮي داﺷﺘﻪ اﺳﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽ دﻫﯿﺪ اﺗﺼﺎل SSD ﻋﻼوه ﺑﺮ ﺳﻬﻮﻟﺖ ﺗﻌﻮﯾﺾ ﻣﯽ ﺗﻮاﻧﺪ ﻋﻤﻠﮑﺮدي ﻣﺸﺎﺑﻪ اﺗﺼﺎﻻت RBS را از ﺧﻮد ﺑﺮوز دﻫﺪ.

One of the drawbacks of the mentioned connections after Northridge and kobe earthquakes was the destruction of beam after earthquake, difficulty and non economical displacement of the beam. Several studies are being carried out on a variety of materials and systems that dissipate the seismic loading effects in order to improve the seismic performance of steel frames. By placing dampers in the beam column connections, damage to the beams and columns, which are very difficult to replace after an earthquake, was prevented during an earthquake. During the design process of dampers, in order to concentrate the earthquake loads on the damper, it was manufactured intentionally with a lower strength than the beams and columns. Through this, beams and columns are protected from damage by utilizing the energy absorption capacity of the damper. Slit damper is a plate or a standard section with a number of slits in the web. The damper is attached to the beam by bolting a plate on the damper under the flange of the beam. In this study first compared slit steel damper connection and connection with the reduced beam section (RBS) under cyclic loading. Some suggestions were provided for improvement of the performance of slit steel damper connection and for making its behavior similar to that of reduced beam section connection and transforming it to a connection which can be used in the special bending frame; and these suggestions include increase in the thickness and number of stripe and decrease in the height. The results and simulations showed that increasing in the number of strips, the increase in thickness and decrease in the height of the SSD damper affects significantly the performance of SSD connection.