ارزیابی اثرات پیچش در سازه‌های فولادی دارای سیستم باربر جانبی ناموازی با پلان نامتقارن

نوع مقاله : Articles

نویسندگان

دانشگاه سمنان

چکیده

با توجه به عدم وجود روابط و ضوابطی مشخص در مورد سازه­های فولادی دارای قاب خمشی و مهاربند همراه با سیستم باربر ناموازی در آیین‌نامه‌های ایران، لزوم بررسی رفتار این‌گونه سازه­ها مورد توجه محققین قرار گرفته است. در این مقاله با مدل‌سازی سه‌بعدی سازه­های فولادی با شش نوع پلان که هرکدام بیانگر مقداری از ناموازی بودن سیستم باربر هستند در مجموع 18 مدل آماده شده، سازه­ها تحت دو نوع بارگذاری دینامیکی خطی و بار افزون مورد بررسی و مطالعه قرار گرفتند. نتایج حاکی از آن است که با افزایش ناموازی بودن سیستم باربر، پیچش سازه­ها نیز افزایش می­یابد. این افزایش برای سازه­های کوتاه‌مرتبه تا 18 برابر و برای سازه‌های میان‌مرتبه تا پنج برابر بیشتر از سازه­های موازی است. اعمال بارگذاری در امتداد سیستم باربر ناموازی نتایج غیر قابل انتظاری را موجب می­شود. افزایش ارتفاع سازه باعث کاهش پیچش در دیافراگم می­شود. بیشترین پیچش دیافراگم مربوط به طبقه­ای است که در ارتفاع 60 الی 70 درصد از تراز پایه ساختمان قرار دارد. در بارگذاری­هایی که در راستای عمود بر سیستم باربر ناموازی صورت می­گیرد، پیچش دیافراگم‌ها در حالت الاستیک و غیر الاستیک تفاوت چندانی با یکدیگر ندارند، درصورتی‌که با بارگذاری در جهت دیگر این تغییرات برای حالت غیر الاستیک گاهی تا بیش از 50 برابر حالت الاستیک است.Assessment of the Effects of Torsion in Steel Structures with Non-Parallel Lateral Resisting System with an Asymmetric PlanMohammad Khoshnam1, Ali Kheyroddin2 and Mohammad Iman Khodakarami3* 1. M.Sc. Graduate, Earthquake Engineering, Faculty of Civil Engineering, Semnan University, Semnan, Iran 2. Professor of Structural Engineering, Faculty of Civil Engineering, Semnan University, Semnan, Iran 3. Assistant Professor of Earthquake Engineering, Faculty of Civil Engineering, Semnan University, Semnan, Iran, * Corresponding Author, email: khodakarami@semnan.ac.ir Keywords: Non-Parallel Resisting System, Steel Moment Resisting Frame, Concentrically Braced Frame, Diaphragm Torsion, Nonlinear Dynamic Analysis, Pushover.--English abstract is in the final page of the pdf file--

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