بررسی تاثیر میراگر لزجی بر ضریب رفتار سازه های بتن مسلح

نوع مقاله : علمی - پژوهشی

نویسندگان

1 استاد، دانشکده مهندسی، دانشگاه فردوسی مشهد، مشهد، ایران

2 گروه عمران دانشکده مهندسی دانشگاه فردوسی مشهد ایران

3 دانشجوی کارشناسی ارشد گروه عمران دانشکده مهندسی دانشگاه فردوسی مشهد ایران

چکیده

امروزه یافتن راه‌های کاهش نیروی زلزله‌، به علت خسارات ناشی از آن، از مهم‌ترین چالش‌ها در زمینه مهندسی زلزله می‌باشد. در این میان انتخاب میراگر غیرفعال لزجی، به علت کم‌هزینه بودن، تکنولوژی مناسب‌تر و رواج استفاده در کشور ارجحیت دارد. در این پژوهش تاثیر میراگر لزجی بر عملکرد لرزه‌ای قاب خمشی بتنی مورد بررسی قرار گرفتهاست. بدین منظور سه قاب خمشی متوسط بتنی 3، 6 و 10 طبقه با نرم‌افزار Sap2000 و بدون اثر میراگر طراحی می‌شوند. سپس، با نرم‌افزارSiesmo struct وارد کردن میراگر مورد تحلیل قرار می‌گیرد. بدین منظور، این قاب‌ها یک بار بدون میراگر و بار دیگر با میراگر لزجی به روش-های معمول، طراحی و سپس زیر اثر بار‌های استاتیکی افزایشی، تحلیل استاتیکی غیرخطی و درنهایت تحت اثر شتاب‌نگاشت‌های زلزله‌های انتخاب شده، تحلیل دینامیکی تاریخچه زمانی می‌شوند.
بر پایه‌ی این بررسی‌ها، مقداری برای ضریب رفتار ناشی از میراگر افزوده به سازه، پیشنهاد می‌شود و با مقادیر موجود در آیین‌نامه2800 و همچنین در زلزله‌های میدان‌دور و میدان‌نزدیک مقایسه می‌شود. نتایج حاکی از افزایش %20 میرایی، تحت تاثیر میراگرهای لزجی، به سازه می‌باشد. ضریب رفتار به‌دست آمده، برمبنای تحلیل استاتیکی غیرخطی بارافزون و تحلیل دینامیکی تاریخچه‌ی زمانی غیرخطی، به ترتیب، 95/0 و 89/0 پیشنهاد می گردد و یا یکدیگر مقایسه می شود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation of behavior factor for reinforced concrete structures by Viscous damper

نویسندگان [English]

  • Hashem Shariatmadar 1
  • Azade Rezayi pazhand 2
  • Negar Rahimzade 3
1 Associated professor, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
2 civil engineering . Ferdowsi university of Mashhad
3 M.Sc student of civil engineering . Ferdowsi university of Mashhad.Iran
چکیده [English]

Nowadays, finding ways to reduce earthquake force due to its damages is one of the most important challenges in the field of earthquake engineering. As a result, the selection of passive Viscouz damper is preferable due to its low cost advantage, more appropriate technology and commen use in country. In this research, the effect of Viscouz damper on seismic performance of concrete moment resisting frame has been investigated. For this purpose, three medium concrete moment resisting frames, which have3, 6 and 10-floors, are designed by the Sap2000 software without damper effect. Then, the damper has been analyzed by siesmo struct software. these frames have been designed by common methods, and then have been studied under the acceleration of selected earthquake mappings by using static pushover and dynamic time history analysis, with and without supplemental viscous dampers. Based on these studies, a value is suggested for the behavior factor of the damper added to the structure and compared with the values contained in the 2800 regulations. Also, this factor is investigated in structures equipped with this damper in far field and near field earthquakes. by including viscous damper, damping increases 20% .the suggested values of the behaviour factor for the static pushover and dynamic time history analysis are 6.29 and 6.23 respectively.

کلیدواژه‌ها [English]

  • Viscous damper
  • Behavior factor
  • Seismic response
  • Nonlinear static analysis
  • Nonlinear time history analysis
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