پديد آورندگان :
حامدي، فرزانه دانشگاه بين المللي امام خميني (ره) - گروه مهندسي عمران , رحماني، كيوان دانشگاه بين المللي امام خميني (ره) - گروه مهندسي عمران , اديب زاده، بنيامين دانشگاه بين المللي امام خميني (ره) - گروه مهندسي عمران
چكيده فارسي :
ﻣﻄﺎﺑﻖ ﺑﺎ ﻟﺰوم ﻣﺒﺤﺚ دﻫﻢ ﻟﺮزهاي ﻣﻘﺮرات ﻣﻠﻲ ﺳﺎﺧﺘﻤﺎن، در اﺗﺼﺎل ازﭘﻴﺶ ﺗﺄﻳﻴﺪ ﺷﺪه ﭘﻴﭽﻲ ﺑﻪﻛﻤﻚ ورقﻫﺎي روﺳﺮي و زﻳﺮﺳﺮي ﻧﺴﺒﺖ دﻫﺎﻧﻪ آزاد ﺗﻴﺮ ﺑﻪ ﻋﻤﻖ ﻣﻘﻄﻊ )L/D( ﺑﺮاي ﻗﺎبﻫﺎي ﺧﻤﺸﻲ ﻣﺘﻮﺳﻂ و وﻳﮋه ﻧﺒﺎﻳﺪ ﺑﻪﺗﺮﺗﻴﺐ ﻛﻤﺘﺮ از 7 و 9 و ﻫﻤﭽﻨﻴﻦ ﺿﺨﺎﻣﺖ ﺑﺎل ﻣﻘﻄﻊ ﺗﻴﺮ ﻧﺒﺎﻳﺪ ﺑﻴﺸﺘﺮاز 30 ﻣﻴﻠﻲﻣﺘﺮ ﻣﻨﻈﻮر ﺷﻮد.از ﻃﺮﻓﻲ، ﮔﺮﭼﻪ ﻋﻤﻖ ﻣﻘﻄﻊ ﺗﻴﺮ ﺑﻪ 1000 ﻣﻴﻠﻲﻣﺘﺮ ﻣﺤﺪود ﺷﺪه اﺳﺖ، ﺑﻪ دﻟﻴﻞ ﻣﻼﺣﻈﺎت ﻣﻌﻤﺎري ﺑﻴﺸﺘﺮاز ﭘﺪﻳﺪ آﻣﺪن آوﻳﺰِ ﺗﻴﺮ در ﺳﻘﻒ اﺟﺘﻨﺎب ﻣﻲﺷﻮد. ﺑﻨﺎﺑﺮاﻳﻦ، اﺳﺘﻔﺎده از اﻳﻦ ﻧﻮع اﺗﺼﺎل از ﭘﻴﺶ ﺗﺄﻳﻴﺪ ﺷﺪه در ﺳﺎﺧﺘﻤﺎنﻫﺎي ﻓﻮﻻدي ﻣﺘﺪاول ﺑﻪ وﻳﮋه ﺑﺎ دﻫﺎﻧﻪﻫﺎي ﻛﻤﻲ ﺑﺰرگ ﺑﻪ دﻟﻴﻞ ﺗﺠﺎور ﻧﺴﺒﺖ دﻫﺎﻧﻪ آزاد ﺗﻴﺮ ﺑﻪ ﻋﻤﻖ ﻣﻘﻄﻊ و ﻳﺎ ﺿﺨﺎﻣﺖ ﺑﺎل ﺗﻴﺮ از ﺣﺪود آﻳﻴﻦﻧﺎﻣﻪاي ﺑﺎ ﭼﺎﻟﺶ ﻣﻮاﺟﻪ ﺷﺪه اﺳﺖ. در اﻳﻦ ﭘﮋوﻫﺶ، ﺑﺮاي ﺑﺮرﺳﻲ اﺛﺮ ﻣﺤﺪودﻳﺖﻫﺎي آﻳﻴﻦﻧﺎﻣﻪاي ﺑﺮ رﻓﺘﺎر ﭼﺮﺧﻪاي اﻳﻦ اﺗﺼﺎل، دوازده ﻧﻤﻮﻧﻪ ﺑﺎ L/D ﺑﺮاﺑﺮ ﺑﺎ 12، 9، 7، 6 و ﺿﺨﺎﻣﺖ ﺑﺎل ﺗﻴﺮ ﺑﺮاﺑﺮ ﺑﺎ 20، 30، 35 ﻣﻴﻠﻲﻣﺘﺮ ﻣﻄﺎﻟﻌﻪ ﺷﺪﻧﺪ. از ﺣﻴﺚ ﺷﻜﻞﭘﺬﻳﺮي، ﻣﺒﻨﺎي ﭘﺬﻳﺮش اﺗﺼﺎل ﺻﻠﺐ در ﻣﻘﺮرات ﻣﻠﻲ ﺳﺎﺧﺘﻤﺎن رﺳﻴﺪن ﺑﻪ دوران ﻣﺎﻧﻨﺪ ﺗﻐﻴﻴﺮ ﻣﻜﺎن ﺟﺎﻧﺒﻲ ﻧﺴﺒﻲ ﻃﺒﻘﻪ ﺣﺪاﻗﻞ ﺑﺮاﺑﺮ ﺑﺎ 0/04 در ﻗﺎبﻫﺎي ﺧﻤﺸﻲ وﻳﮋه و 0/02 در ﻗﺎبﻫﺎي ﺧﻤﺸﻲ ﻣﺘﻮﺳﻂ ﺑﺪون اﻓﺖ ﻗﺎﺑﻞ ﺗﻮﺟﻪ ﻣﻘﺎوﻣﺖ اﺳﺖ. ﻧﺘﺎﻳﺞ ﺑﻪ دﺳﺖ آﻣﺪه ﻧﺸﺎن ﻣﻲدﻫﺪ ﻛﻪ ﺑﻪﻛﺎرﮔﻴﺮي اﻳﻦ ﻧﻮع اﺗﺼﺎل در ﻗﺎبﻫﺎي ﺧﻤﺸﻲ وﻳﮋه ﺑﺎ L/D ﺑﺮاﺑﺮ ﺑﺎ 7 و اﻓﺰاﻳﺶ ﺿﺨﺎﻣﺖ ﺑﺎل ﻣﻘﻄﻊ ﺗﺎ 35 ﻣﻴﻠﻲﻣﺘﺮ ﺣﺪ ﺷﻜﻞ ﭘﺬﻳﺮي زﻳﺎد را ﺗﺄﻣﻴﻦ ﻧﻤﻮده و ﺑﻨﺎﺑﺮاﻳﻦ ﻗﺎﺑﻞ ﻗﺒﻮل اﺳﺖ. ﻫﻤﭽﻨﻴﻦ اﺗﺼﺎﻟﻲ ﻛﻪ ﺿﺨﺎﻣﺖ ﺑﺎل ﻣﻘﻄﻊ ﺗﻴﺮ آن ﺑﻪ 30 ﻣﻴﻠﻲﻣﺘﺮ ﻣﺤﺪود ﺷﺪه اﺳﺖ ﺗﺎ L/D ﺑﺮاﺑﺮ ﺑﺎ 12 ﺷﻜﻞ ﭘﺬﻳﺮي ﻣﺪ ﻧﻈﺮ ﻣﻘﺮرات ﻣﻠﻲ ﺑﺮاي ﻗﺎبﻫﺎي ﺧﻤﺸﻲ وﻳﮋه را ﺑﺮآورده ﻣﻲﻧﻤﺎﻳﺪ. در ﺧﺼﻮص ﻗﺎبﻫﺎي ﺧﻤﺸﻲ ﻣﺘﻮﺳﻂ ﻧﻴﺰ ﺑﻪ ﻛﺎرﮔﻴﺮي اﺗﺼﺎل ﭘﻴﭽﻲ ﺑﻪﻛﻤﻚ ورقﻫﺎي روﺳﺮي و زﻳﺮﺳﺮي ﺑﺎ ﻧﺴﺒﺖ دﻫﺎﻧﻪ آزاد ﺗﻴﺮ ﺑﻪ ﻋﻤﻖ ﻣﻘﻄﻊ ﺗﺎ 12 و ﺿﺨﺎﻣﺖ ﺑﺎل ﺗﻴﺮ ﺗﺎ 35 ﻣﻴﻠﻲﻣﺘﺮ ﺣﺪود ﺷﻜﻞ ﭘﺬﻳﺮي ﻣﺮﺑﻮط ﺑﻪ ﻗﺎبﻫﺎي ﺧﻤﺸﻲ ﻣﺘﻮﺳﻂ را ﺑﺮآورده ﻧﻤﻮده و ﺑﻨﺎﺑﺮاﻳﻦ ﻗﺎﺑﻞ ﻗﺒﻮل اﺳﺖ.
چكيده لاتين :
Understanding the exact real performance of rigid connections in steel moment frames is very important. Not paying enough attention in connection design process may lead to not only local connection damages but also other structural memberschr('39') failure or even building collapse. According to seismic requirements of the tenth topic of national building regulations of Iran, clear span to depth ratio of beam (L/D) in the prequalified bolted flange plate moment connection shall be limited to 7 and 9 or greater respectively for intermediate moment frames and special moment frames and the beam flange thickness shall be limited to 30 millimeters too. Although the beam depth is limited to 1000 millimeters in this type of prequalified moment connection, due to architectural limitations and urbanism requirements, it is usually unacceptable to design such deep beam in the conventional residential buildings. So, in spite of its wide use and practical utility because of exceeding the clear span to depth ratio or beam flange thickness limitations, applying this kind of moment connection in steel moment frame structures is sometimes impossible specially in big span structures. To study the effect of these limitations on cyclic behavior of aforementioned rigid connection towel samples in L/D of 6, 7, 9, 12 and beam flange thickness of 20, 30, 35 were considered and modeled in a finite element software. First of all, the moment connection designed to have enough strength. Then, in term of ductility, the moment connection acceptance criterion is to count the rotation corresponding to related inter story displacement of 0.04 and 0.02 in special moment frames and intermediate moment frames respectively. The results show that applying this type of connection in special moment frames in L/D of 7 and beam flange thickness up to 35 millimeters provides required ductility, and thus, is acceptable. In addition, the moment connection in L/D up to 12 which itchr('39')s flange thickness limited to 30 millimeters has enough ductility to pass seismic requirements of the tenth topic of national building regulations. In intermediate steel moment frames, applying bolted flange plate connection in clear span to depth ratio of beam up to 12 and the beam flange thickness up to 35 millimeters fulfills the seismic requirements. Comparison between models was shown that although by increasing the beam flange thickness and decreasing clear span to depth ratio of beam, the strength of connection is improved up to 37%, the connection ductility is reduced and so, the connection capacity is decreased. The von Mises stress distribution in samples show that the plastic hinges are almost located on the last row of bolts from column faces. The maximum stress in beams which observed in distance range of 20 to 100 centimeters from column faces has exceeded the yield stress and shows protected zone. As expected, the beams failure mode is top or bottom plate buckling. As a research suggestion, it seems that it is possible to combine these three limitations (clear span to depth ratio of beam, beam section flange thickness, and beam section depth) to gain a more comprehensive and useful phrase.
