مطالعه ﺗﺤﻠﯿﻠﯽ ﺗﺄﺛﯿﺮ ورقﻫﺎي ﺗﻘﻮﯾﺘﯽ در ﺑﻬﺒﻮد ﻋﻤﻠﮑﺮد ﻟﺮزهاي ﻏﯿﺮﺧﻄﯽ اﺗﺼﺎل ﺧﻤﺸﯽ ﺗﯿﺮ ﭘﯿﻮﻧﺪ ﺑﻪ ﺳﺘﻮن در ﻗﺎبﻫﺎي ﻣﻬﺎرﺑﻨﺪي واﮔﺮا

Analytical Assessment of Effects of Cover Plates on Improvement the Seismic Nonlinear Behavior of Moment Link to Column Connections in Eccentrically Braced Frames

در ﺳﯿﺴﺘﻢ ﻗﺎﺑﻬﺎي ﻣﻬﺎرﺑﻨﺪي ﺷﺪه واﮔﺮا، ﺷﮑﻞ ﭘﺬﯾﺮي ﻣﻮرد ﻧﯿﺎز و ﻧﯿﺰ ﺑﺨﺶ ﻋﻤﺪه اي از ﺟﺬب و اﺳﺘﻬﻼك اﻧﺮژي ﺳﯿﺴﺘﻢ، ﺗﻮﺳﻂ ﺗﯿﺮ ﭘﯿﻮﻧﺪ ﺻﻮرت ﻣﯽ ﭘﺬﯾﺮد. ﺗﻮاﻧﺎﯾﯽ ﺗﯿﺮ ﭘﯿﻮﻧﺪ در ﺟﺬب و اﺳﺘﻬﻼك اﻧﺮژي ﺑﺴﺘﮕﯽ ﺑﻪ ﻣﺸﺨﺼﺎت و ﺟﺰﺋﯿﺎت ﻫﻨﺪﺳﯽ آن دارد. ﺑﺴﯿﺎري از آﯾﯿﻦﻧﺎﻣﻪﻫﺎ و دﺳﺘﻮراﻟﻌﻤﻞﻫﺎي ﻃﺮاﺣﯽ ﺳﺎزهﻫﺎي ﻓﻮﻻدي ازﺟﻤﻠﻪ ﻣﺒﺤﺚ دﻫﻢ ﻣﻘﺮرات ﻣﻠﯽ ﺳﺎﺧﺘﻤﺎن اﯾﺮان، ﭘﯿﺸﻨﻬﺎدي ﺑﺮاي اﺗﺼﺎل ﮔﯿﺮدار ﺗﯿﺮ ﭘﯿﻮﻧﺪ ﻣﺘﺼﻞ ﺑﻪ ﺳﺘﻮن در ﻗﺎبﻫﺎي ﺑﺎ ﻣﻬﺎرﺑﻨﺪ واﮔﺮا ﻣﻄﺮح ﻧﮑﺮدهاﻧﺪ. ﻟﺬا ﻃﺮاﺣﯽ اﺗﺼﺎﻻت ﭘﯿﻮﻧﺪ ﺑﻪ ﺳﺘﻮن در ﻗﺎب ﻫﺎي ﻣﻘﺎوم در ﺑﺮاﺑﺮ زﻣﯿﻦ ﻟﺮزه، ﺑﺎ ﻣﻬﺎرﺑﻨﺪي واﮔﺮا ﺑﻪ ﺻﻮرت ﯾﮏ ﻣﺸﮑﻞ ﺣﻞ ﻧﺸﺪه ﺑﺎﻗﯽ ﻣﺎﻧﺪه اﺳﺖ. در ﻣﻘﺎﻟﻪ ﺣﺎﺿﺮ ﺑﻪ ﻣﻄﺎﻟﻌﻪ ﺗﺤﻠﯿﻠﯽ ﺗﺄﺛﯿﺮ اﻓﺰودن ورقﻫﺎي ﺗﻘﻮﯾﺘﯽ در ﺑﻬﺒﻮد ﻋﻤﻠﮑﺮد ﻟﺮزهاي اﺗﺼﺎل ﮔﯿﺮدار ﺗﻘﻮﯾﺖ ﻧﺸﺪه ﺗﯿﺮ ﭘﯿﻮﻧﺪ و ﺑﺮآورده ﮐﺮدن ﻧﯿﺎز ﺷﮑﻞﭘﺬﯾﺮي اﺗﺼﺎل ﺑﺎ اﺳﺘﻔﺎده از روش اﺟﺰاي ﻣﺤﺪود ﭘﺮداﺧﺘﻪﺷﺪه اﺳﺖ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﻣﻌﯿﺎر ﺗﺸﺨﯿﺺ ﺷﮑﺴﺖ ﻧﻤﻮﻧﻪﻫﺎ از ﺗﻄﺒﯿﻖ ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺶﻫﺎ ﺑﺎ ﻣﻌﯿﺎر ﮐﺮﻧﺶ ﭘﻼﺳﺘﯿﮏ ﺣﺪاﮐﺜﺮ، ﻣﻌﺮﻓﯽ ﮔﺮدﯾﺪه اﺳﺖ. اﺗﺼﺎﻻت ﺟﻮﺷﯽ ﺗﯿﺮ ﭘﯿﻮﻧﺪ ﺑﻪ ﺳﺘﻮن، ﻗﺒﻞ از دوران ﻻزم ﺗﯿﺮ ﭘﯿﻮﻧﺪ، ﻣﺴﺘﻌﺪ ﺷﮑﺴﺖ در ﺑﺎل ﺗﯿﺮ ﭘﯿﻮﻧﺪ ﻣﯽﺑﺎﺷﻨﺪ ﻟﺬا ﺳﻪ ﺗﯿﭗ ورق ﺗﻘﻮﯾﺘﯽ ﺟﻬﺖ ﺑﻪ ﺗﺄﺧﯿﺮ اﻧﺪاﺧﺘﻦ ﺷﮑﺴﺖ در اﺗﺼﺎل ﺑﺮرﺳﯽﺷﺪه اﺳﺖ. رﻓﺘﺎر اﺗﺼﺎﻻت ﺗﻘﻮﯾﺖﺷﺪه ﻧﺸﺎن داد ﮐﻪ ورق ﺗﻘﻮﯾﺖﮐﻨﻨﺪه ﻣﺜﻠﺜﯽ ﺷﮑﻞ ﺑﻬﺘﺮﯾﻦ ﻋﻤﻠﮑﺮد را دارد.

Many codes and regulations for designing of steel structures the same as 10th part of Iranian national buildings code don’t offer any solution link-to-column connection in eccentric braced frames. In eccentrically braced frames (EBF), required ductility and a major part of absorption and energy depreciation is done by link to column connection. The ability of link in absorb and depreciate energy is depended on specification and geometric details. So design of link-to-column connection in resistant frames to earthquake with eccentrically braced frames remains an unsolved problem. This paper is discussing about the effect of adding cover plates on improving the seismic behavior of not reinforced moment connection of the link beam and preparing the ductility demand of connection by finite elements method. In this paper the model fracture recognition is introduced with adopting the experimental results with the maximum plastic strain index. Welded link-to-column connections have the potential to fracture in the wing of link beam, before adequate rotation. So three types of cover plates are assessed to delay the fracture of connection. The result was that the triangular cover plates have the best performance.The result was that the triangular cover plates have the best performance.The result was that the triangular cover plates have the best performance.