Analisis Kehandalan Anjungan Lepas Pantai Tipe Jacket Berdasarkan Kapasitas Fatigue pada Sambungan
DOI:
https://doi.org/10.5614/jts.2007.14.2.3Keywords:
Struktur jacket, Analisis kehandalan, Kelelahan.Abstract
Abstrak. Konsep dasar dari analisis kehandalan menyatakan bahwa kapasitas dan faktor beban adalah suatu besaran statistik dengan nilai rata-rata, standar deviasi, dan memiliki bentuk probabilitas tertentu (misalnya bentuk probabilitas normal, log normal, dan lain-lain). Ketika kapasitas dan beban tersebut diekspresikan dalam bentuk fungsi performansi, maka terdapat suatu probabilitas dimana beban melebihi kapasitas struktur; probabilitas ini adalah probabilitas kegagalan (Pf) dan kehandalan dinyatakan dengan (1- Pf). Dalam makalah ini diuraikan konsep dasar dan aplikasi analisis kehandalan berdasarkan kapasitas fatigue (kelelahan) pada sambungan, dengan mengambil studi kasus anjungan lepas pantai tipe jacket. Pembahasan difokuskan pada evaluasi persamaan fungsi performansi akhir dengan pendekatan semi probabilitas.Abstract. The fundamental concept for reliability analysis is that resistance and load factors are statistical quantities with mean value, variance and some form of distribution (probability density function, e.g. Normal, Log Normal, etc). When combined together via an expression to describe the limit state, there will be a finite probability that the load will exceed the resistance; this defines the probability of failure (Pf) and since reliability is equal to (1- Pf). This paper will discuss the basic consideration involved in a reliability based on joint's fatigue capacity approach for the design and analysis of jacket offshore structure. Emphasis will be placed on a systematic semiprobabilistic approach in evaluation of fatigue limit state function.
References
American Petroleum Institute, 1997, "Recomended Practise for Planning, Designing and Constructing Fixed offshore Platform - Load and Resistance Factor Design" , Washington, D.C.
Engineering Dynamic, Inc., 2003, SACS Release 5 Collapse and Fatigue User's Manual, Louisiana.
Ersdal, Gerhard, 2005, Doctoral Thesis Assessment of Existing Offshore Structures for Life Extension.
Department of Mechanical and Structural Engineering and Material Science University of Stavanger, October.
JCSS Probabilistic Model Code, Draft, 2004, "Fatigue Model For Metalic Structures" , jcssfat.
Onoufriou, Toula, 1999, "Reliability Based Inspection Planning of Offshore Structures" , Journal of Marine Structures 12 521-539.
Skjong, R., Gregersen, E.B., Cramer, E., Croker, A., Hagen, ., Korneliussen, G., Lacasse, S., Lotsberg, I., Nadim, F., Ronold, K.O., 1995, "Guideline for Offshore Structural Reliability Analysis-General" , DNV:95-2018.
Tawekal, R.L., Aria R., Baskara, dan Adriadi, R., 2004, "Studi Kehandalan Struktur Anjungan Lepas Pantai Tipe Braced Monopod" , Jurnal Teknik Sipil ITB Vol. 11 No. 4, Bandung, Oktober.
