نویسنده
دانشکده مهندسی عمران، دانشگاه تبریز
چکیده
امکان تطبیق نتایج حاصل از مدل تجربی سازه‌ها با نتایج حاصل شده از مدل المان محدود متناظر یکی از الزامات مهم در طراحی به‌شمار می‌رود. در این زمینه، با به‌روزرسانی مدل با استفاده از سیگنال‌های اندازه‌گیری شده در آزمایش ارتعاش، می‌توان مدل المان محدود مناسبی را پیشنهاد کرد. از این‌رو، این مقاله با استفاده از تهیه و انجام آزمایش روی مدل قاب فضایی سازه جکتی فراساحلی در مقیاس کوچک در یک آزمایشگاه دینامیک سازه و ارتعاشات، مطالعه‌ای را در مورد روشهای عددی به‌روزرسانی مستقیم و غیرمستقیم ارائه می‌دهد. همین‌طور در آن با استفاده از آنالیز حساسیت پاسخ سیستم به یک تحریک پایه، رویه انتخاب درجات آزادی غیر‌فعال در مرحله کاهش مدل با یک معیار مناسب مورد ارزیابی قرار می‌گیرد. این عملکرد منجر به همگرایی سریع‌تر الگوریتم تکرار و همچنین حذف مودهای کم اثر می‌شود. از آنجایی که مسأله اصلی در مسائل مرتبط با آنالیز دینامیکی سازه‌ها، پرهزینه و زمان‌بر بودن محاسبات است بنابراین با استفاده از این روش‌ها هم در زمان و هم در هزینه صرفه‌جویی خواهد شد.
کلیدواژه‌ها
عنوان مقاله [English]
Finite Element Model Updating of an Offshore Jacket Platforms using Experimental Modal Analysis
نویسنده [English]
- F. Hosseinlou
چکیده [English]
An important requirement in design is to be able to compare experimental results from prototype structures with predicted results from a corresponding finite element model. In this context, updating the model using measured vibration test can lead to proposing a desired finite element model. Therefore, this paper presents indirect and direct based numerical updating study of a reduced scale four-story spatial frame structure of offshore jacket platforms constructed and tested at the Structural Dynamics and Vibration Laboratory. Besides, the selection procedure for inactive degrees of freedom in the process of reduced model is evalated, with a reasonable criterion, by using sensitivity analysis of system response under base excitation. This performance leads to faster convergence of iterative algorithm and also, eliminates spurious modes. Since the significant problem fundamental to dynamic structural analysis is the amount of time and cost required for computation, the use of these methods will save both in time and cost.
کلیدواژه‌ها [English]
- Offshore jacket platforms
- optimization
- Numerical updating
- experimental modal analysis
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