Mawardi, Rafi Manaf (2026) Analisis Kelelahan Mooring Chain Pada Single Point Mooring Ardjuna Marine Terminal Akibat Kombinasi Beban Gelombang, Arus, Dan Angin Dengan Metode Fracture Mechanics. Other thesis, Institut Teknologi Sepuluh Nopember.
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Abstract
Kegagalan mooring chain pada sistem Single Point Mooring (SPM) merupakan salah satu risiko kritis dalam operasi lepas pantai akibat pembebanan lingkungan yang bersifat siklik dan kompleks. Kombinasi gelombang, arus, dan angin menghasilkan fluktuasi tegangan yang dapat memicu inisiasi dan perambatan retak, sehingga berpotensi menurunkan integritas struktur. Penelitian ini bertujuan untuk menganalisis perilaku kelelahan mooring chain pada SPM Ardjuna Marine Terminal menggunakan pendekatan mekanika kepecahan (fracture mechanics). Retak dimodelkan sebagai semi-elliptical surface crack, sedangkan perilaku perambatan retak dianalisis menggunakan Hukum Paris berdasarkan nilai Stress Intensity Factor (SIF) yang diperoleh melalui simulasi numerik metode elemen hingga. Hasil penelitian menunjukkan bahwa nilai SIF maksimum mencapai 1821,8 MPa√mm dengan deviasi sebesar 1,6% terhadap solusi analitik, yang mengonfirmasi keandalan model numerik yang digunakan. Laju perambatan retak meningkat dari 2,65 × 10⁻⁸ mm/siklus hingga 3,02 × 10⁻⁵ mm/siklus seiring bertambahnya ukuran retak, menunjukkan terjadinya percepatan pertumbuhan retak akibat peningkatan nilai SIF. Selain itu, laju perambatan retak kumulatif diperoleh sebesar 1,01 × 10⁻⁴ mm/siklus. Berdasarkan integrasi Hukum Paris, umur kelelahan mooring chain diperkirakan mencapai 4,15 × 10⁷ siklus atau setara dengan 8,3 tahun operasi sebelum mencapai ukuran retak kritis yang ditinjau dalam penelitian ini. Hasil penelitian menunjukkan bahwa peningkatan ukuran retak memberikan pengaruh signifikan terhadap percepatan perambatan retak dan penurunan umur kelelahan mooring chain. Temuan ini menegaskan pentingnya penerapan pendekatan mekanika kepecahan dalam evaluasi integritas struktur serta sebagai dasar pengembangan strategi inspeksi dan pemeliharaan berbasis kondisi untuk meningkatkan keandalan sistem tambat lepas pantai.
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Failure of mooring chains in Single Point Mooring (SPM) systems represents a critical risk in offshore operations due to complex cyclic environmental loading. The combined effects of waves, currents, and wind generate significant stress fluctuations that may initiate and propagate cracks, ultimately compromising structural integrity. This study investigates the fatigue behavior of a mooring chain in the Ardjuna Marine Terminal SPM system using a fracture mechanics approach. A semi-elliptical surface crack was modeled, and crack growth behavior was evaluated using the Paris Law based on the Stress Intensity Factor (SIF) obtained from finite element simulations. The results show that the maximum SIF reached 1821.8 MPa√mm, with a deviation of only 1.6% from the analytical solution, confirming the reliability of the numerical model. Crack growth rates increased progressively from 2.65×10⁻⁸ mm/cycle to 3.02×10⁻⁵ mm/cycle as crack depth increased from 0.5 mm to 9 mm, indicating accelerated crack propagation driven by the nonlinear increase in SIF. The cumulative crack propagation rate was calculated as 1.01×10⁻⁴ mm/cycle. Based on Paris Law integration, the fatigue life of the mooring chain was estimated to be 4.15 × 10⁷ cycles, equivalent to approximately 8.3 years of operation before the crack reached the critical size considered in this study. These findings demonstrate the significant influence of combined environmental loading on fatigue degradation and highlight the importance of fracture mechanics-based assessment for condition-based inspection and maintenance planning of offshore mooring systems.
| Item Type: | Thesis (Other) |
|---|---|
| Uncontrolled Keywords: | Mooring chain, Single Point Mooring (SPM), umur kelelahan, perambatan retak, Stress Intensity Factor (SIF), Hukum Paris, mekanika kepecahan, Mooring chain, Single Point Mooring (SPM), Material Fatigue, Crack Propagation, Stress Intensity Factor (SIF), Paris Law, Fracture Mechanics. |
| Subjects: | T Technology > TC Hydraulic engineering. Ocean engineering > TC1665 Offshore structures--Materials. T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures |
| Divisions: | Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis |
| Depositing User: | Rafi Manaf Mawardi |
| Date Deposited: | 15 Jun 2026 05:54 |
| Last Modified: | 15 Jun 2026 05:54 |
| URI: | http://repository.its.ac.id/id/eprint/133801 |
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