Studi Eksperimental Roll Decay Test Pada Tongkang Menggunakan Penyesuaian Kurva Ekstingsi

Gadas, Roufuraja Martkussa (2026) Studi Eksperimental Roll Decay Test Pada Tongkang Menggunakan Penyesuaian Kurva Ekstingsi. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Stabilitas merupakan parameter fundamental dalam perancangan bangunan apung yang berkaitan erat dengan keselamatan operasional, di mana gerak oleng (roll) menjadi salah satu respons paling krusial karena berpotensi menyebabkan kapal terbalik (capsizing). Penentuan nilai redaman oleng (roll damping) secara akurat sangat diperlukan, namun seringkali kompleks akibat karakteristik hambatan viskos non-linier, terutama pada lambung tongkang (barge) yang berbentuk kotak. Penelitian ini bertujuan untuk mengevaluasi secara numerik dan eksperimental karakteristik roll damping pada model Floating Production Unit (FPU) barge berskala 1:49 dalam kondisi terapung bebas (free-floating) di perairan tenang. Data time trace peluruhan oleng hasil pengujian diekstrapolasi ke skala aktual (1:1) menggunakan hukum Froude untuk menghitung periode natural dan parameter kinematika. Penurunan amplitudo dievaluasi pada siklus puncak (peak-to-peak) dan lembah (trough-to-trough) untuk memodelkan kurva ekstingsi menggunakan pendekatan linier (Metode A) dan kuadratik (Metode B). Hasil penelitian menunjukkan peluruhan amplitudo dari 4,18° hingga 0,89° dalam 11 siklus osilasi, dengan redaman linier mendominasi redaman kuadratik. Ekstraksi kurva ekstingsi menghasilkan nilai rata-rata koefisien regresi Metode A (q = 0,1083; r = 0,0204) dan Metode B (q = 0,1039; r = 0,0222). Konversi parameter ini pada skala penuh menghasilkan koefisien damping linier (b1) sebesar 8,28 × 10⁸ kg·m²·s⁻¹ dan damping kuadratik (b2) 3,17 × 10⁸ kg·m² untuk Metode A, serta b1 = 7,94 × 10⁸ kg·m²·s⁻¹ dan b2 = 3,44 × 10⁸ kg·m² untuk Metode B. Nilai koefisien hidrodinamika ini diharapkan dapat menjadi rujukan analitis dalam mengevaluasi stabilitas dinamis dan persamaan gerak pada struktur tongkang.
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Stability is a fundamental parameter in the design of floating structures and is closely related to operational safety, wherein roll motion is one of the most critical responses due to its potential to cause capsizing. Accurately determining roll damping is essential but often complex due to non-linear viscous resistance characteristics, particularly in box-shaped barge hulls. This study aims to numerically and experimentally evaluate the roll damping characteristics of a 1:49 scale Floating Production Unit (FPU) barge model in a free-floating condition within still water. The roll decay time trace data from the experiment was extrapolated to full scale (1:1) using Froude's law to calculate natural periods and kinematic parameters. Amplitude decrements were evaluated across peak-to-peak and trough-to-trough cycles to model extinction curves using linear (Method A) and quadratic (Method B) approaches. The results demonstrated an amplitude decay from 4.18° to 0.89° over 11 oscillation cycles, with linear damping dominating over quadratic damping. The extinction curve extraction yielded mean regression coefficients for Method A (q = 0.1083; r = 0.0204) and Method B (q = 0.1039; r = 0.0222). The full-scale conversion of these parameters resulted in a linear damping coefficient (b1) of 8.28 × 10⁸ kg·m²·s⁻¹ and a quadratic damping coefficient (b2) of 3.17 × 10⁸ kg·m² for Method A, while Method B yielded b1 = 7.94 × 10⁸ kg·m²·s⁻¹ and b2 = 3.44 × 10⁸ kg·m². These hydrodynamic coefficients are expected to serve as analytical references for evaluating the dynamic stability and equations of motion in barge structures.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Redaman Oleng, Uji Peluruhan Oleng, Tongkang (FPU), Kurva Ekstingsi, Koefisien Redaman Linier (
Subjects:	T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures V Naval Science > V Naval Science (General) V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM161 Ships--Hydrodynamics V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM453 Oceanographic research ships. V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM761 Stability of ships
Divisions:	Faculty of Marine Technology (MARTECH) > Offshore Engineering > 54040-(S1) Undergraduate Thesis
Depositing User:	Roufuraja Martkussa Gadas
Date Deposited:	28 Jul 2026 03:38
Last Modified:	28 Jul 2026 03:38
URI:	http://repository.its.ac.id/id/eprint/138378

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