ﺑﺮرﺳﯽ و ﺗﻌﯿﯿﻦ ﻣﻘﺎوﻣﺖ ﺿﺮﺑﻪ اي ﺟﻮش ﻫﺎي ﺷﯿﺎري و ﻣﻘﺎﯾﺴﻪ آن ﺑﺎ ﺿﻮاﺑﻂ ﻟﺮزه اي اﺗﺼﺎﻻت ﺟﻮﺷﯽ

Investigation and Determine of Impact Toughness of Groove Welds and Comparing with Seismic Provisions of Weld Connections

ﺟﻠﻮﮔﯿﺮي از ﺷﮑﺴﺖ ﺗٌﺮد در ﺟﻮش اﺗﺼﺎﻻت اﻋﻀﺎي ﻓﻮﻻدي ﯾﮑﯽ از ﻣﺴﺎﺋﻞ ﺑﺴﯿﺎر ﻣﻬﻢ در ﻋﻤﻠﮑﺮد ﺳﺎزهﻫﺎي ﻓﻮﻻدي اﺳﺖ. ﺗﺠﺮﺑﻪﻫﺎي ﺗﻠﺦ زﻟﺰﻟﻪ ﻧﻮرثرﯾﭻ در ﺧﺼﻮص ﺟﻮشﻫﺎي ﺑﻪ ﮐﺎر رﻓﺘﻪ در اﺗﺼﺎﻻت و وﺻﻠﻪﻫﺎي اﻋﻀﺎي ﺳﯿﺴﺘﻢ ﺑﺎرﺑﺮ ﺟﺎﻧﺒﯽ ﻟﺮزهاي و ﻧﯿﺰ در ﺟﻮشﻫﺎي "ﻧﯿﺎز ﺑﺤﺮاﻧﯽ"؛ ﻧﻈﯿﺮ ﺟﻮشﻫﺎي ﺷﯿﺎري ﺑﺎ ﻧﻔﻮذ ﮐﺎﻣﻞ)CJP( در اﺗﺼﺎل ﺗﯿﺮ ﺑﻪ ﺳﺘﻮن در ﻗﺎبﻫﺎي ﺧﻤﺸﯽ ﻓﻮﻻدي ﻣﺤﻘﻘﺎن را ﺑﻪ اﯾﻦ ﻧﺘﯿﺠﻪ رﺳﺎﻧﺪ ﮐﻪ ﺑﻪ ﻣﻨﻈﻮر ﺟﻠﻮﮔﯿﺮي از ﮐﺎﻫﺶ ﺷﮑﻞﭘﺬﯾﺮي و ﺟﻠﻮﮔﯿﺮي از ﺷﮑﺴﺖ ﺗﺮد، ﺑﺎﯾﺴﺘﯽ ﻣﻘﺎوت ﺿﺮﺑﻪاي ﺟﻮش در دﻣﺎي ﻣﻌﯿﻨﯽ ﺗﺄﻣﯿﻦ ﺷﻮد. اﻟﺰاﻣﺎت ﻟﺮزهاي آﯾﯿﻦ-ﻧﺎﻣﻪ AISC و ﺑﻪ ﺗﺒﻊ آن ﻣﺒﺤﺚ دﻫﻢ ﻣﻘﺮّرات ﻣﻠﯽ ﺳﺎﺧﺘﻤﺎن اﯾﺮان ﺑﺮاي ﺟﻮشﻫﺎي ﻣﺬﮐﻮر ﻃﺎﻗﺖ ﻧﻤﻮﻧﻪ ﺷﯿﺎر داده ﺷﺎرﭘﯽ در دﻣﺎي ﻣﻌﯿﻨﯽ را ﺗﻮﺻﯿﻪ ﻣﯽﻧﻤﺎﯾﻨﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﺑﻪ ﻣﻨﻈﻮر ﺣﺼﻮل اﻃﻤﯿﻨﺎن از ﻣﻘﺎوت ﺿﺮﺑﻪاي و ﭼﻘﺮﻣﮕﯽ ﺟﻮشﻫﺎي اﺟﺮا ﺷﺪه در ﺷﺮاﯾﻂ ﻣﺘﻌﺎرف اﯾﺮان، آزﻣﺎﯾﺶ ﺷﺎرﭘﯽ در ﻧﻤﻮﻧﻪﻫﺎي ﺑﺎ ﺿﺨﺎﻣﺖﻫﺎي ﻣﺘﻌﺪد و ﺑﺎ اﻟﮑﺘﺮودﻫﺎي راﯾﺞ ﺗﺤﺖ ﺟﻮﺷﮑﺎري دﺳﺘﯽ و ﺟﻮﺷﮑﺎري زﯾﺮﭘﻮدري اﻧﺠﺎم ﺷﺪه و ﻧﺘﺎﯾﺞ آن ﺑﺎ اﻟﺰاﻣﺎت ﻣﺒﺤﺚ دﻫﻢ ﻣﻘﺎﯾﺴﻪ ﺷﺪه اﺳﺖ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از ﺟﻮش ﺷﯿﺎري ﺑﺎ اﻟﮑﺘﺮود E6013 در روش ﺟﻮﺷﮑﺎري دﺳﺘﯽ و ﻫﻤﭽﻨﯿﻦ ﺟﻮش ﺷﯿﺎري اﺟﺮا ﺷﺪه ﺑﻪ روش زﯾﺮ ﭘﻮدري ﺗﺄﻣﻞ ﺑﺮاﻧﮕﯿﺰ اﺳﺖ.

Preventing brittle fracture in the connection welds of the steel members is one of the most important issues in the performance of steel structures. Bitter experiences of Northridge earthquake in the case of “demand critical” welds such as complete-joint-penetration (CJP) groove welds in the connections of steel moment frames forced researchers to conclude that for preventing decrease in ductility and preventing brittle fracture of welds, it should be that impact toughness of welds must be provided at the determined temperature. Seismic Requirements of AISC and following of it the 10th topic of Iranian national building Requirements for the mentioned welding recommends Charpy-v-notch toughness at the determined Test temperature. In this research, to ensure impact toughness of preformed welds in the common conditions of Iran, the Charpy Test in the specimens of multiple thicknesses and common electrodes has been done with Shielded Metal Arc Welding (SMAW) and Submerged Arc Welding (SAW) and the conclusions of them compared with the 10th topic requirements. It has been shown that impact toughness of groove weld in SMAW process with E6013 electrode and groove weld in SAW process doesn’t matched with requirements of present Codes, but for other electrodes there was no contradiction.