توسعه یک چارچوب محاسباتی برای تحلیل قابلیت اعتماد متغیر در زمان در سکوهای ثابت فلزی فراساحل

نوع مقاله: مقاله پژوهشی

نویسندگان

1 استادیار دانشکده مهندسی عمران دانشگاه صنعتی خواجه نصیرالدین طوسی

2 دانشجوی دکتری دانشکده مهندسی دریا، دانشگاه صنعتی امیرکبیر

چکیده

در این مطالعه با توجه به اهمیت تحلیل قابلیت اعتماد در ارزیابی احتمالاتی وضعیت سکوهای موجود، یک چارچوب محاسباتی مبتنی بر روش‌های احتمالاتی ارائه می‌گردد. برای انجام تحلیل قابلیت اعتماد بر روی سکوهای ثابت دریایی از روش FORM استفاده شده است. در رویکرد تحلیل قابلیت اعتماد به کار گرفته شده در این مطالعه، نیروهای محیطی یا پاسخ سازه در هر گام از تحلیل قابلیت اعتماد مستقیما محاسبه می‌شود. این چارچوب احتمالاتی برای تحلیل 3 سکوی فراساحلی موجود که در سال‌های مختلف طراحی، ساخته و نصب شده‌اند، بکار گرفته شده است و احتمال شکست سالانه در سال‌های مختلف در طول عمر بهره‌برداری از سکو محاسبه شده است. مقایسه نتایج بدست آمده از تحلیل قابلیت اعتماد سکوها نشان می‌دهد که با توجه به کاهش کارایی سیستم حفاظت از خوردگی پس از پایان عمر طراحی سکوها، مقدار احتمال شکست به فرم یک تابع درجه 2 افزایش می‌یابد. همچنین، سکوهایی که با استانداردهای گذشته طراحی شدهاند، شاخص قابلیت‌اعتماد پایینتری نسبت به سکوهای طراحی شده در سال‌های اخیر دارند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

A Computational Framework for Time-Dependent Reliability Analysis of Jacket Type Offshore Platforms

نویسندگان [English]

  • Hossein Gholami 1
  • Ahmad Izadi 2
1 Civil Engineering Faculty, K.N. Toosi University of Technology
2 Department of maritime engineering, AmirKabir University of Technology
چکیده [English]

In this paper, with regards to the importance of the reliability analysis in the probabilistic assessment of existing offshore platforms, a probabilistic-based computational framework is presented. For reliability analysis of jacket platforms, FORM is used. In this approach, the environmental loads or the structural response in each step of reliability analysis calculated directly. This probabilistic framework is applied for reliability analysis of 3 jacket platforms which are designed, fabricated, and installed in different years. The annual probability of failure is computed in different years of platform service life. Comparison of result demonstrated that due to reducing the performance of the corrosion protection system after the design life of the platform, the amount of probability of failure increased in the parabolic form with the second order. Also, the reliability index for the old designed platform is lower than a platform designed in latest years.

کلیدواژه‌ها [English]

  • Fixed offshore platforms
  • Reliability
  • Assessment
  • Probability of Failure
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