Analisis Kelelahan pada Pipeline End Manifold (PLEM) Akibat Beban Siklis (Tension) dari Subsea Hose

Pratama, Rizal Arif (2026) Analisis Kelelahan pada Pipeline End Manifold (PLEM) Akibat Beban Siklis (Tension) dari Subsea Hose. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

PHE ONWJ berencana untuk keberlangsungan penyaluran minyak mentah dari Central Plant ke Floating Storage and Offloading (FSO) dengan melaksanakan penggantian pipa dan Pipeline End Manifold (PLEM) untuk meningkatkan integritas dan keadandalan dari fasilitas Marine Terminal. Perubahan konfigurasi akibat pemasangan subsea pipeline dan PLEM baru menimbulkan interaksi dinamis antara subsea hose yang tersambung ke PLEM baru dan PLEM lama berbeda sehingga beban pada struktur PLEM baru juga berbeda. Mengingat pentingnya peran PLEM dalam proses pengaliran minyak mentah dari sumur di wilayah kerja ONWJ menuju FSO, penelitian ini bertujuan melakukan analisis kelelahan pada Pipeline End Manifold (PLEM) akibat beban siklis (tension) dari subsea hoses. Tujuan penelitian ini untuk memprediksi umur kelelahan struktur PLEM baru dengan menggunakan Palmgren-Miner Rules. Penelitian dimulai dengan menganalisis sistem mooring dan subsea hoses yang terhubung ke PLEM baru untuk mengidentifikasi besarnya beban tarik yang bekerja pada struktur. Analisis dilakukan menggunakan simulasi dinamis untuk memperoleh time history gaya tarik. Hasil time history tersebut kemudian diproses menjadi nilai tension range cycle dengan metode siklus Rainflow. Selanjutnya, untuk mengevaluasi distribusi tegangan akibat beban siklis dari subsea hoses, dilakukan local stress analysis menggunakan metode hotspot stress melalui analisis elemen hingga (Finite Element Analysis / FEA) mengacu pada standar DNV-RP-C203. Hasil analisis hotspot stress digunakan untuk menghitung umur lelah struktur PLEM baru. Hasil penelitian menunjukkan bahwa umur lelah terendah pada struktur PLEM baru terjadi pada sambungan antara pipe support dan skid, dengan umur lelah sebesar 17,63 tahun dan rasio kerusakan sebesar 0,0113. Sebaliknya, sambungan antara elbow pipe dan flange memiliki umur lelah yang jauh lebih tinggi, yaitu 499,38 tahun dengan rasio kerusakan 4 × 10⁻⁴.
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PHE ONWJ intends to maintain the continuity of delivering crude oil from the Central Plant to the Floating Storage and Offloading (FSO) by replacing pipelines and Pipeline End Manifolds (PLEM) to improve the integrity and reliability of the Marine Terminal facilities. The configuration changes resulting from the installation of new pipelines and PLEM alter the dynamic interactions between the subsea hoses connected to the New PLEM and Old PLEM, leading to different load conditions on the new PLEM structure. Considering the important of PLEM in crude oil transfer process from wells within the ONWJ working area to the FSO, thus this research will conduct a fatigue analysis of the Pipeline End Manifold (PLEM) due to cyclic loads (tension) from subsea hoses. The objective of this research is to predict the fatigue life of New PLEM structure by applying Palmgren-Miner Rule. The study will begin with an analysis of the mooring lines system and subsea hoses connected to the new PLEM to identify the cyclic tension loads acting on the structure. The analysis was performed using time domain simulation with output in the form of a tension time history. The results of the time tension history will then be processed to find the tension range cycle value using the Rainflow cycle counting method. Furthermore, to assess the stress distribution caused by cyclic loads from the subsea hoses, a local stress analysis will be performed using hotspot stress method by finite element analysis (FEA) which refers to DNV-RP-C203. The result of hotspot stress analysis will be used for the fatigue life calculation of the New PLEM A structure. The analysis results show that the lowest fatigue life of the new PLEM A structure occurs at the connection between pipe support and skid, with a fatigue life value of 17.63 years and a damage ratio of 0.0113. In contrast, the connection between the elbow pipe and flange exhibits a significantly higher fatigue life of 499.38 years and a damage ratio of 4 × 10⁻⁴.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Kelelahan, PLEM, Subsea Hoses, Tension, Marine Terminal, Fatigue
Subjects:	T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures
Divisions:	Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38101-(S2) Master Thesis
Depositing User:	Rizal Arif Pratama
Date Deposited:	02 Feb 2026 04:55
Last Modified:	02 Feb 2026 04:55
URI:	http://repository.its.ac.id/id/eprint/131530

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