Analisis Umur Kelelahan Mooring Line terhadap Variasi Konfigurasi dan Material pada Platform OC4-DeepCWind

Pratama, Bima Sakti (2026) Analisis Umur Kelelahan Mooring Line terhadap Variasi Konfigurasi dan Material pada Platform OC4-DeepCWind. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Floating Offshore Wind Turbine (FOWT) merupakan salah satu teknologi energi terbarukan yang dikembangkan untuk memanfaatkan potensi angin pada perairan laut dalam. Salah satu komponen penting pada FOWT adalah sistem tambat karena berfungsi mempertahankan posisi platform terhadap beban lingkungan. Selama masa operasi, mooring line menerima pembebanan siklik yang dapat menyebabkan akumulasi kerusakan fatigue. Penelitian ini bertujuan untuk menganalisis pengaruh variasi konfigurasi dan material mooring line terhadap respons dinamis, tension, faktor keamanan, dan umur kelelahan pada platform OC4-DeepCWind. Penelitian dilakukan secara numerik dengan memodelkan platform semisubmersible OC4-DeepCWind. Analisis hidrodinamika dilakukan untuk memperoleh karakteristik respons struktur, sedangkan analisis dinamis domain waktu digunakan untuk memperoleh respons gerak platform dan time history tension pada mooring line. Variasi yang dianalisis meliputi sistem catenary berbahan chain dengan konfigurasi 3×1 dan 3×2, serta sistem taut berbahan wire rope dengan konfigurasi 3×1 dan 3×2. Analisis fatigue dilakukan menggunakan metode rainflow counting, kurva T-N, dan aturan Palmgren-Miner berdasarkan API RP 2SK. Hasil penelitian menunjukkan bahwa sistem taut wire rope mampu membatasi respons translasi platform secara signifikan, dengan rata-rata surge di bawah 0,15 m, sedangkan sistem catenary chain menghasilkan rata-rata surge hingga 7,78 m pada kondisi in-line. Namun, sistem taut menghasilkan maximum tension yang lebih tinggi, dengan nilai terbesar 3.047,52 kN pada konfigurasi 3×1 taut kondisi in-line. Seluruh variasi memenuhi kriteria faktor keamanan minimum API RP 2SK sebesar 1,67. Dari aspek fatigue, nilai umur kelelahan terendah diperoleh pada konfigurasi 3×1 catenary kondisi in-line sebesar 157,04 tahun, sedangkan nilai tertinggi diperoleh pada konfigurasi 3×2 taut kondisi between-line sebesar 394.918,19 tahun. Hasil ini menunjukkan bahwa konfigurasi, material, dan tipe sistem tambat berpengaruh terhadap distribusi tension dan umur kelelahan mooring line.
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A Floating Offshore Wind Turbine (FOWT) is a renewable energy technology developed to utilize wind resources in deep-water areas. One of the key components of an FOWT is the mooring system, which maintains the platform position under environmental loading. During operation, mooring lines are subjected to cyclic loading that may cause fatigue damage accumulation. This study aims to analyze the effects of mooring line configuration and material variations on the dynamic response, tension, safety factor, and fatigue life of the OC4-DeepCWind platform. This study was conducted numerically by modeling the OC4-DeepCWind semisubmersible platform. Hydrodynamic analysis was performed to obtain the structural response characteristics, while time-domain dynamic analysis was used to obtain platform motion responses and mooring line tension time histories. The analyzed variations consisted of a chain-based catenary system with 3×1 and 3×2 configurations, and a wire-rope-based taut system with 3×1 and 3×2 configurations. Fatigue analysis was carried out using rainflow counting, T-N curves, and the Palmgren-Miner rule based on API RP 2SK. The results show that the taut wire rope system significantly reduces the translational response of the platform, with an average surge below 0.15 m, while the catenary chain system produces an average surge of up to 7.78 m under in-line loading. However, the taut system generates higher maximum tension, with the highest value of 3,047.52 kN occurring in the 3×1 taut configuration under in-line loading. All variations satisfy the minimum safety factor criterion of API RP 2SK, which is 1.67. In terms of fatigue, the lowest fatigue life is obtained in the 3×1 catenary configuration under in-line loading, with a value of 157.04 years, while the highest fatigue life is obtained in the 3×2 taut configuration under between-line loading, reaching 394,918.19 years. These results indicate that mooring configuration, material, and mooring system type affect the tension distribution and fatigue life of the mooring lines.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	FOWT, OC4-DeepCWind, mooring line, fatigue life, catenary, taut, chain, wire rope, FOWT, OC4-DeepCWind, mooring line, fatigue life, catenary, taut, chain, wire rope.
Subjects:	T Technology > T Technology (General) > T57.62 Simulation T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures T Technology > TJ Mechanical engineering and machinery > TJ808 Renewable energy sources. Energy harvesting.
Divisions:	Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis
Depositing User:	Bima Sakti Pratama
Date Deposited:	24 Jul 2026 02:17
Last Modified:	24 Jul 2026 02:17
URI:	http://repository.its.ac.id/id/eprint/136960

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