Analisa Kekuatan Memanjang Double Hull CPO Barge Pengaruh Heaving-Pitching Couple dan Distribusi Beban

Ramadhan, Afrizal (2010) Analisa Kekuatan Memanjang Double Hull CPO Barge Pengaruh Heaving-Pitching Couple dan Distribusi Beban. Masters thesis, Institut Teknologi Sepuluh November.

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Abstract

Kebutuhan transportasi laut mutlak diperlukan, mulai dari kebutuhan angkut logistik hingga sumber daya alam. Salah satu jenis alat transportasi laut yang saat ini banyak dibutuhkan adalah CPO Barge. Namun, untuk memperkecil terjadinya kecelakaan yang berakibat pada tumpahan minyak dari kapal, persyaratan untuk jenis barge bermuatan cair adalah menggunakan double hull. Persyaratan ini diberlakukan oleh Oil Pollution Act of 1990 (OPA'90), International Maritime Organization (IMO), dan MARPOL (13 F & G). Penentuan ini merupakan salah satu syarat dalam mendesain kapal. Pada barge, terdapat daerah kritis, yaitu longitudinal strength (kekuatan memanjang), akibat pengaruh gelombang. Secara umum, perhitungan dimensi yang aman dari setiap elemen struktur kapal dapat ditentukan oleh desainer kapal berdasarkan beban yang bekerja pada kapal tersebut atau faktor internal, serta stress (tegangan) dan deflection (defleksi) akibat faktor eksternal. Persyaratan desain yang diizinkan untuk stress (tegangan) dan deflection (defleksi) akibat beban eksternal yang memberikan beban ekstrem adalah beban gelombang yang mengakibatkan hogging dan sagging. Beban ini merupakan couple heaving-pitching pada arah gelombang 0 derajat dan 180 derajat, dengan variasi pembebanan berupa muatan spesifik, yaitu ballast saat bongkar muat dan muatan penuh. Kondisi sea state 3 menggunakan variasi tinggi gelombang 0,5 m hingga 2,5 m. Analisis struktur menggunakan metode elemen hingga. Diperoleh tiga kondisi kritis, yaitu pada saat muatan penuh dengan arah gelombang 0 derajat dan 180 derajat di station 38, serta pada saat muatan kosong dengan arah gelombang 0 derajat di station 4 dan arah 180 derajat di station 30. Pada station 4, diperoleh tegangan maksimum $\sigma_{\text{max}} = 46,4$ MPa. Pada arah 180° di station 30, terjadi tegangan maksimum $\sigma_{\text{max}} = 226$ MPa, sedangkan pada arah 0° di station 38, terjadi tegangan maksimum $\sigma_{\text{max}} = 220$ MPa. Pada arah 180° di station 38, terjadi tegangan maksimum $\sigma_{\text{max}} = 157$ MPa. Tegangan izin yang digunakan dalam penelitian ini mengacu pada standar BKI, yaitu $\sigma_{\text{izin}} = 253$ MPa. Dengan demikian, station 38, station 4, dan station 30 telah memenuhi standar BKI. Untuk analisis selanjutnya, dapat dilakukan pemodelan towing sehingga diperoleh nilai yang lebih akurat terhadap kondisi sebenarnya.
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Sea transportation is absolutely necessary, ranging from the transportation of logistics to natural resources. One type of marine transportation that is currently in high demand is the CPO barge. However, to minimize accidents that may result in oil spills from ships, liquid cargo barges are required to use a double hull. This requirement is established by the Oil Pollution Act of 1990 (OPA '90), the International Maritime Organization (IMO), and MARPOL (13 F & G). This requirement must be considered in ship design. Barges have a critical area related to longitudinal strength due to the influence of waves. In general, the safe dimensions of each structural element of a ship can be determined by ship designers based on the loads acting on the vessel, including internal factors, as well as stress and deflection caused by external factors. The design must also comply with the allowable stress and deflection limits under external loading conditions. Extreme wave loads that cause hogging and sagging are considered in the analysis. These loads involve the heaving-pitching couple at wave headings of 0° and 180°, with different loading conditions, namely ballast during loading and unloading and full cargo load. The analysis considers Sea State 3 conditions, with wave heights ranging from 0.5 m to 2.5 m. Structural analysis is performed using the finite element method. Three critical conditions are identified: the full-load condition at wave headings of 0° and 180° at Station 38, the empty-load condition at a wave heading of 0° at Station 4, and the empty-load condition at a wave heading of 180° at Station 30. At Station 4, the maximum stress obtained is $\sigma_{\text{max}} = 46.4$ MPa. At a wave heading of 180° at Station 30, the maximum stress is $\sigma_{\text{max}} = 226$ MPa, while at a wave heading of 0° at Station 38, the maximum stress is $\sigma_{\text{max}} = 220$ MPa. At a wave heading of 180° at Station 38, the maximum stress is $\sigma_{\text{max}} = 157$ MPa. The allowable stress used in this study follows the BKI standard, with an allowable stress of $\sigma_{\text{allowable}} = 253$ MPa. Therefore, the stress values at Stations 38, 4, and 30 are within the allowable limits specified by BKI. For further analysis, physical modeling in a towing tank is recommended to obtain more accurate and reliable results that better represent actual operating conditions.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	longitudinal strength, beban gelombang, double hull, Heaving- pitching couple, longitudinal strength, wave loads, double hull, Heaving-pitching couple
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:	magang .
Date Deposited:	13 Oct 2026 03:12
Last Modified:	13 Oct 2026 03:12
URI:	http://repository.its.ac.id/id/eprint/145507

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