ارزیابی عملکرد لرزه‌ای سیستم‌های مهاربند واگرا بدون اعضا قطری

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی عمران، دانشگاه صنعتی امیرکبیر، تهران، ایران

2 پژوهشکده سازه و زلزله، دانشگاه صنعتی امیرکبیر، تهران، ایران

چکیده

سیستم‌های مهاربند واگرا به واسطه شکل‌پذیری قابل قبول و سختی متناسبی که از خود نشان می‌دهند به عنوان یکی از سیستم‌های باربر در برابر بار جانبی در نظر گرفته می‌شوند. علی‌رغم محاسن این نوع سیستم‌ها آنها دارای معایبی نیز می‌باشند که نیاز به بهبود رفتار آنها را ضروری می‌سازد. یکی از این محدودیت‌ها عدم ایجاد فضای معماری کافی به خصوص در دهانه‌های کوتاه است. همین امر باعث استفاده از لینک‌های با طول بلند در دهانه‌های کوتاه می‌شود که از لحاظ عملکردی نسبت به لینک‌های با طول کوتاه جذب انرژی ضعیف‌تری دارند. محدودیت دیگر مهاربندهای واگرا، تعویض هزینه‌زا و زمان‌بر آن‌ها است. ایده استفاده از لینک‌های قابل تعویض می‌تواند زمان و هزینه تعمیر و بازسازی سیستم‌ را کاهش دهد. در این پژوهش ایده حذف المان مورب در مهاربندهای واگرا و افزایش عمق تیر خارج از لینک پیشنهاد می‌شود تا علاوه بر دست‌یابی به سختی متناسب، فضای معماری ارتقا یافته نیز برای طراحان فراهم گردد. همچنین با استفاده از اتصال قابل تعویض لینک به تیر اصلی، امکان تعمیر کم‌هزینه‌تر سازه پس از وقوع حادثه وجود خواهد داشت. در این تحقیق علاوه بر مطالعات آزمایشگاهی، ایده پیش‌گفته با استفاده از مدل‌های عددی نیز مورد بررسی قرار می‌گیرد. در همین راستا، برای یافتن نسبت بین افزایش ابعاد تیر خارج از لینک و سختی قاب، اقدام به مدل‌سازی عددی 572 نمونه با افزایش تدریجی ابعاد تیر قاب بدون مهاربند می‌گردد. در نهایت با استفاده از یادگیری ماشین رابطه‌ای بین افزایش ابعاد تیر و افزایش سختی قاب متناظر به منظور ارتقای میزان جذب انرژی و شکل‌پذیری سیستم پیشنهاد می‌گردد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Seismic Evaluation of eccentrically braced frames without diagonal members

نویسندگان [English]

  • Farid Mahmoudi 1
  • Alireza Rahai 1
  • Hatami Farzad 2
1 Amirkabir university of technology
2
چکیده [English]

Eccentrically braced frames are one type of lateral load-bearing system due to their acceptable ductility and proportional stiffness. However, they have some limitations that need improvement. One limitation is insufficient architectural space creation, especially for short spans which leads to using link beams with intermediate and long lengths that have weaker energy absorption compared to links with short lengths. Another limitation is their costly and time-consuming replacement. To address these limitations, this research proposes removing diagonal elements from eccentrically braced frames and increasing beam depth outside links which provides more proportional stiffness and improved architectural space for designers. Additionally, using replaceable connections between links and main beams reduces repair costs after earthquakes. Numerical modeling was used to investigate this idea along with laboratory studies. Finally, the ratio between increased beam depth outside links and frame stiffness was found through numerical modelling samples with gradual increases in beam depth without braces.

کلیدواژه‌ها [English]

  • Eccentrically Braced Frame
  • Shear Link
  • Short Span
  • Experiment
  • Numerical Modelling
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