بررسی ضابطه ستون قوی- تیر ضعیف در اتصالات از پیش تایید شده جوشی در قاب های خمشی فولادی با شکل پذیری متوسط

نوع مقاله : علمی - پژوهشی

نویسندگان

1 دانشیار، دانشکده عمران،دانشگاه سمنان

2 کارشناسی ارشد سازه، دانشکده مهندسی عمران، دانشگاه سمنان، سمنان، ایران.

چکیده

گسیختگی ستون‌ها عموماً منجر به ایجاد مکانیزم طبقه نرم و فروریختگی کل سازه می‌شود، همچنین به علت وجود نیروی محوری ستون‌ها، تسلیم ستون‌ها در اثر برش و خمش، افت مقاومت بیشتری نسبت به تسلیم تیرها ایجاد می‌کند. از این رو آیین‌نامه‌های طراحی الزام می‌دارند تا در کلیه گره‌های اتصالات خمشی تیر به ستون در قابهای فولادی با شکل پذیری ویژه ضابطه ستون قوی – تیر ضعیف کنترل گردد. در این مطالعه به بررسی ضابطه ستون قوی – تیر ضعیف در اتصالات خمشی از پیش تایید شده جوشی شامل اتصال تیر با سطح مقطع کاهش یافته، اتصال با ورق‌های روسری و زیرسری و اتصال مستقیم تقویت نشده جوشی در قاب خمشی فولادی با شکلپذیری متوسط پرداخته شده است. نتایج مطالعات نشان داد که عدم رعایت ضابطه ستون قوی – تیر ضعیف بر روی عملکرد اتصالات مطرح شده تاثیر گذار بوده و موجب گردیده است که مفصل پلاستیک در ستون تشکیل شود و همچنین باعث کاهش جذب انرژی، سختی و ظرفیت باربری اتصالات شده است. در نتیجه پیشنهاد شده است که برای عملکرد هر چه بهتر اتصالات خمشی از پیش تایید شده جوشی در قابهای خمشی فولادی با شکل پذیری متوسط و همچنین افزایش سطح اطمینان این نوع از اتصالات، رابطه ستون قوی تیر ضعیف کنترل گردد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Evaluation of Using Strong Column-Weak Beam Requirements in Prequalified Welded Connections in Intermediate Steel Moment Frame

نویسندگان [English]

  • Mohammad Ali Kafi 1
  • payam tarighi 2
1 Faculty of Civil Engineering., Semnan University, Semnan, Iran
2 M.Sc. Structural Engineering, Faculty of Civil Engineering, Semnan University
چکیده [English]

Beams are genarally used to face bendind force and columns are used to face axial load. as the seismic load comes parallely with respect to earth surface. so the column faces the load pependicularly which is very risky for the column. after that load gets distributed to all the beams. for this reason columns must be strong to make the structure more earth quake resistant.Generally column failure is reason of soft story and collapse of structure Also, because of the axial load yield of columns in shear and moment forces cause loss of strength more than beams and other elements. Structural design codes have a requirement for strength column and weak beam in all joints of special moment connection. In this research strength column and weak beam in prequalified moment connection like reduced beam section (RBS), cover plate connection (WFP) and the welded unreinforced flange-welded web (WUF-W) connection in intermediate moment frames studied. Results shown that ignore strung column and weak beam requirements effect function of the connection and cues to plastic hinge formed in a column. This is effect reduce energy abortion, stiffness and bearing capacity of connections. so as a result it was suggested that for better perfomance prequalified welded connections in intermediate steel moment frame controlled strong columns weak beams requirements.

کلیدواژه‌ها [English]

  • Soft story
  • Strong column-weak beam
  • Intermediate ductility
  • Moment connection
  • Energy abortion
  • stiffness
  • Bearing Capacity
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