Analisis Ultimate Limit Strength Akibat Kerusakan Struktur Alas Kapal Menggunakan Metode Elemen Hingga

Pangaribuan, Toga Gilbert (2026) Analisis Ultimate Limit Strength Akibat Kerusakan Struktur Alas Kapal Menggunakan Metode Elemen Hingga. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Kapal yang sudah berusia di atas 25 tahun rentan mengalami kegagalan struktur yang mayoritas terjadi di area midship section. Analisis ultimate limit strength perlu dilakukan untuk mengetahui ultimate strength struktur terutama pada alas di daerah midship yang mengalami kerusakan. Dalam analisis ini, digunakan lima variasi model kerusakan berupa crack dengan pembebanan kompresi memanjang dan beban lateral. Variasi kerusakan mencakup crack yang berada pada pelat dan penegar, dengan lokasi di 1/4 dan 1/2 jarak bentang dari kondisi batas. Ketidaksempurnaan awal turut dimodelkan sebagai representasi dampak proses fabrikasi kapal. Analisis numerik dilakukan menggunakan metode elemen hingga dengan pendekatan implicit dynamic. Hasil komputasi menunjukkan bahwa keberadaan kerusakan dan ketidaksempurnaan awal menyebabkan penurunan kekuatan maksimum struktur. Model intact memiliki kekuatan maksimum sebesar 402.48 MPa, sedangkan model kerusakan dengan imperfeksi awal menunjukkan tegangan maksimum sebesar 349.44 MPa. Peningkatan dimensi crack terbukti menurunkan kekuatan maksimum secara signifikan pada struktur berpenegar di setiap lokasi. Selain itu, model dengan crack yang berada lebih dekat ke kondisi batas 1/4 a memiliki tegangan maksimum yang lebih tinggi dibandingkan model dengan crack di tengah bentang. Pada kondisi kegagalan, deformasi akhir struktur alas kapal mengikuti ketidaksempurnaan awal yang diterapkan
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Ships that are over 25 years old are prone to structural failure, which predominantly occurs in the midship section. Therefore, an ultimate limit strength analysis is required to evaluate the ultimate strength of ship structures, particularly the bottom structure in the damaged midship region. In this study, five variations of damage models in the form of cracks are considered under longitudinal compressive loading and lateral loads. The damage variations include cracks located on plates and stiffeners, positioned at 1/4 and 1/2 of the span length measured from the boundary condition. Initial imperfections are also introduced to represent the effects of ship fabrication processes. Numerical analysis is carried out using the finite element method with an implicit dynamic approach. The computational results indicate that the presence of damage and initial imperfections leads to a reduction in the structural maximum strength. The intact model exhibits a maximum strength of 402.48 MPa, while the damaged model with initial imperfections shows a maximum stress of 349.44 MPa. An increase in crack size is found to significantly reduce the maximum strength of stiffened structures at all investigated locations. In addition, models with cracks located closer to the boundary condition 1/4 a exhibit higher maximum stress compared to those with cracks located at mid-span. At the failure condition, the final deformation of the ship bottom structure follows the applied initial imperfections.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Ultimate limit strength, crack, ketidaksempurnaan awal, struktur, dimensi,lokasi, crack, initial imperfection, structure, dimention, and location.
Subjects:	V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM156 Naval architecture
Divisions:	Faculty of Marine Technology (MARTECH) > Naval Architecture and Shipbuilding Engineering > 36201-(S1) Undergraduate Thesis
Depositing User:	Toga Gilbert Pangaribuan
Date Deposited:	02 Feb 2026 07:37
Last Modified:	02 Feb 2026 09:32
URI:	http://repository.its.ac.id/id/eprint/131657

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