Affandy, Mochammad Agus Nuriel (2020) Analisis Umur Kelelahan (Fatigue Life) Menggunakan Metode Spectral-Based Fatigue Analysis Pada Struktur Keramba Jaring Apung Ocean Farm Its (OFITS). Undergraduate thesis, Institut Teknologi Sepuluh Nopember.
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Abstract
Dalam tugas akhir ini, penulis menganalisis umur kelelahan struktur (fatigue life) KJA (Keramba Jaring Apung) OFITS di Pantai Sendang Biru, Malang. Penelitian dimulai dengan menentukan titik COG (Centre of Gravity), COB (Centre of Buoyancy), dan COF (Centre of Flotation) dengan mempertimbangkan berat struktur dan beban yang diterima struktur. Selanjutnya menghitung kekakuan hidrostatik struktur untuk gerakan heave, roll, dan pitch. Nilai kekakuan hidrostatik digunakan untuk mensimulasikan gerakan struktur akibat beban lingkungan. Setelah itu melakukan perhitungan nilai SCF (Stress Concentration Factors) pada semua sambungan (joint) untuk member struktur yang berbentuk tubular dan analisis pergerakan struktur KJA akibat beban lingkungan dalam keadaan tertambat untuk mendapatkan besar tension mooring line. Dilakukan analisis global dengan memasukkan tension yang mengenai struktur akibat tali tambat dan beban lingkungan untuk mendapatkan respon struktur yaitu fatigue load akibat beban yang diterima. Dari hasil analisis, didapatkan periode natural struktur untuk gerakan Heave sebesar 6.519 detik, Roll sebesar 4.471 detik, Pitch sebesar 4.525 detik. Untuk analisis umur kelelahan dengan metode spektra menggunakan safety factor sebesar 2 berdasarkan API RP 2A WSD, didapatkan nilai cumulative damage (D) terbesar 2.622 dan service life terendah sebesar 7.628 tahun untuk masa operasi.
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In this final project, authors analyzed fatigue life of Floating Net Cages Ocean Farm ITS (OFITS) Structure in Sendang Biru Beach, Malang. This research begins with calculating COG (Centre of Gravity), COB (Centre of Buoyancy), and COF (Centre of Flotation) by considering total mass of structure and apllied load to the structure. Next step is calculating hydrostatic stiffness of structure for heave, roll, and pitch motions. The value of hydrostatic stiffness is using for simulating motion of structure based on the environmental load. After that, calculating SCF (Stress Concentration Factors) for all tubular member and analysing motion of the floating net cages structure due to the environmental load in moored condition to obtain a value of mooring line tension. Global analysing is performed with applying tension from mooring system and environtmental load to get a structure response or fatigue load. The results of analysis are obtained natural period structure for Heave motion is 6.519 second, for Roll motion is 4.471 second, for Pitch motions is 4.525 second. For spectral fatigue analysis using safety factor 2 based on API RP 2A WSD, with maximum cumulative damage (D) is 2.622 and the lowest service life is 7.628 year.
| Item Type: | Thesis (Undergraduate) |
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| Uncontrolled Keywords: | Aquaculture, Natural Period, Stress Concentration Factors, Hidrostatic Stiffness, Spectral Fatigue Analysis, Akuakultur, Periode Natural, Stress Concentration Factors, Kekakuan Hidrostatik, Analisis Umur Kelelahan Metode Spektra |
| Subjects: | T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures |
| Divisions: | Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis |
| Depositing User: | Mochammad Agus Nuriel Affandy |
| Date Deposited: | 13 Aug 2020 08:46 |
| Last Modified: | 12 May 2023 03:09 |
| URI: | http://repository.its.ac.id/id/eprint/77934 |
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