Analisis Keandalan Struktur WHP-C Terhadap Kelelahan Akibat Korosi

Samudra, Salsadila Audiary (2021) Analisis Keandalan Struktur WHP-C Terhadap Kelelahan Akibat Korosi. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Salah satu kegagalan yang dihadapi struktur laut berkaitan dengan riwayat
pembebanan yang kompleks selama service life adalah terjadinya kelelahan. Fatigue
disebabkan oleh pengaruh beban lingkungan yang diberikan secara terus menerus selama
masa operasi sehingga struktur akan mengalami stress pada lokasi tertentu. Fatigue terjadi
dari munculnya retak pada salah satu bagian struktur yang kemudian menjalar sehingga
mengalami kegagalan. Cacat las pada sambungan chord dan brace salah satu penyebab
timbulnya retak. Struktur berada pada lingkungan laut yang mengandung garam sehingga
kemungkinan terjadinya korosi semakin besar. Agar tidak terjadi kegagalan suatu
dilakukan analisis keandalan untuk mengetahui kemampuan dari suatu struktur dalam
memenuhi tujuan desain dengan rentang waktu tertentu. Dalam penelitian ini dibahas
analisis keandalan pada struktur WHP-C terhadap beban kelelahan pada jacket akibat
korosi. Analisis kelelahan dihitung dengan metode full spectral fatigue analysis, sedangkan
analisis keandalan menggunakan simulasi Monte Carlo. Korosi yang digunakan yaitu 0.21
cm, 0.32 cm, dan 0.48 cm. Pada joint 850 yang merupakan bukan member primer leg
dengan brace, masing –masing kondisi korosi memiliki umur kelelahan 301 tahun, 294
tahun, dan 236 tahun. Kemudian pada member primer leg dengan brace joint 203L masing
–masing kondisi korosi memiliki umur kelelahan 1256 tahun, 1051 tahun, dan 566 tahun.
Pada perhitungan Monte Carlo struktur WHP-C memiliki keandalan struktur 0.9877,
0.9827, dan 0.9642.
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One of the failures faced by marine structures related to the complex loading history
during the service life is the occurrence of fatigue. Fatigue is caused by the influence of
environmental loads that are continuously applied during the operation period so that the
structure will experience stress at certain locations. Fatigue occurs from the appearance
of cracks in one part of the structure which then spreads to failure. Welding defects in
chord and brace joints are one of the causes of cracks. The structure is located in a marine
environment that contains salt so that the possibility of corrosion is greater. In order to
avoid a failure, a reliability analysis is carried out to determine the ability of a structure to
meet design objectives within a certain time span. This study discusses the reliability
analysis of the WHP-C structure against fatigue loads on the jacket due to corrosion.
Fatigue analysis is calculated using full spectral fatigue analysis method, while reliability
analysis uses Monte Carlo simulation. The corrosion used are 0.21 cm, 0.32 cm, and 0.48
cm. In joint 850 which is not a primary member of the braced leg, each corrosion
condition has a fatigue life of 301 years, 294 years, and 236 years. Then on the primary
leg member with brace joint 203L, each corrosion condition has a fatigue life of 1256
years, 1051 years, and 566 years. In the Monte Carlo calculation, the WHP-C structure
has a structural reliability of 0.9877, 0.9827, and 0.9642.

Item Type:	Thesis (Undergraduate)
Uncontrolled Keywords:	Jacket, Korosi, Kelelahan, Spectral, Keandalan, Monte Carlo, Corrosion, Fatigue, Reliability
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA645 Structural analysis (Engineering)
Divisions:	Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis
Depositing User:	Salsadila Audiary Samudra
Date Deposited:	12 Aug 2021 10:21
Last Modified:	12 Aug 2021 10:21
URI:	http://repository.its.ac.id/id/eprint/86213

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