Studi Pengaruh Pemasangan Strut Terhadap Kekuatan Dan Berat Struktur Kapal

Nasatya, Azrul Mahastra (2026) Studi Pengaruh Pemasangan Strut Terhadap Kekuatan Dan Berat Struktur Kapal. Other thesis, Institut Teknologi Sepuluh Nopember.

Text 5018221022-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (8MB) | Request a copy

Abstract

Struktur double bottom pada kapal tanker berfungsi sebagai elemen utama yang menahan beban hidrostatik eksternal dan beban internal muatan, sehingga pemilihan konfigurasi struktur yang tepat sangat menentukan kekuatan dan efisiensi berat kapal. Salah satu upaya optimasi yang dapat dilakukan adalah dengan menambahkan elemen strut pada struktur double bottom untuk mereduksi modulus penampang bottom longitudinal dan inner bottom longitudinal, namun pengaruh penambahan strut terhadap distribusi tegangan dan berat struktur secara komprehensif masih perlu dikaji lebih lanjut. Penelitian ini bertujuan untuk menganalisis pengaruh pemasangan strut terhadap distribusi tegangan Von Mises dan berat struktur double bottom kapal tanker dengan variasi tinggi double bottom (Hdb) sebesar 1,3 m, 1,5 m, dan 1,7 m, serta variasi jarak pembujur (spacing) sebesar 600 mm, 650 mm, dan 700 mm, sehingga diperoleh 18 model kombinasi variasi struktur tanpa dan dengan strut. Metode yang digunakan meliputi perhitungan scantling berdasarkan BKI Rules for the Classification and Construction of Seagoing Steel Ships Volume II – Rules for Hull, pemodelan geometri midship section menggunakan AutoCAD, pemodelan tiga dimensi dan analisis kekuatan struktur menggunakan metode Finite Element Method (FEM) pada perangkat lunak ANSYS Static Structural, dilengkapi studi konvergensi mesh untuk memperoleh ukuran elemen optimum, serta verifikasi tegangan izin dan pemeriksaan buckling pada elemen strut. Hasil analisis menunjukkan bahwa pemasangan strut secara konsisten menurunkan tegangan Von Mises maksimum pada inner bottom longitudinal dan bottom longitudinal dibandingkan struktur tanpa strut, meskipun disertai peningkatan tegangan pada elemen strut dan pelat inner bottom. Verifikasi terhadap tegangan izin BKI menunjukkan seluruh model memenuhi kriteria accepted, kecuali model M17-700-S yang memerlukan penambahan tebal pelat inner bottom longitudinal dari 9 mm menjadi 10 mm agar memenuhi syarat. Dari sisi berat, seluruh model dengan strut memiliki berat struktur yang lebih ringan dibandingkan tanpa strut, dengan penghematan berat berkisar antara 2,31% hingga 4,25%, sedangkan hubungan antara tinggi double bottom maupun jarak pembujur terhadap berat struktur bersifat nonlinier akibat interaksi perubahan dimensi berbagai elemen struktur sesuai ketentuan scantling BKI. Berdasarkan hasil tersebut dapat disimpulkan bahwa penggunaan strut pada struktur double bottom kapal tanker mampu memperbaiki distribusi tegangan sekaligus menghasilkan efisiensi berat struktur.
==============================================================================================================================
The double bottom structure of a tanker plays a critical role in withstanding external hydrostatic loads and internal cargo loads, making the selection of an appropriate structural configuration essential for ensuring both strength and weight efficiency. One optimization approach that can be applied is the installation of a strut element in the double bottom structure to reduce the required section modulus of the bottom longitudinal and inner bottom longitudinal, although its comprehensive effect on stress distribution and structural weight still requires further investigation. This study aims to analyze the influence of strut installation on the Von Mises stress distribution and structural weight of a tanker's double bottom structure, considering variations in double bottom height (Hdb) of 1.3 m, 1.5 m, and 1.7 m, as well as longitudinal spacing of 600 mm, 650 mm, and 700 mm, resulting in 18 combined model variations both with and without struts. The method applied includes scantling calculation based on the BKI Rules for the Classification and Construction of Seagoing Steel Ships Volume II – Rules for Hull, geometric modeling of the midship section using AutoCAD, three-dimensional modeling and structural strength analysis using the Finite Element Method (FEM) in ANSYS Static Structural, supported by a mesh convergence study to obtain the optimum element size, as well as verification against permissible stress and buckling checks on the strut element. The results show that strut installation consistently reduces the maximum Von Mises stress on the inner bottom longitudinal and bottom longitudinal compared to structures without struts, although it is accompanied by an increase in stress on the strut element and the inner bottom plate. Verification against BKI permissible stress shows that all models are accepted, except for model M17-700-S, which requires an increase in inner bottom longitudinal plate thickness from 9 mm to 10 mm to meet the criteria. In terms of weight, all models with struts exhibit lower structural weight compared to those without struts, with weight savings ranging from 2.31% to 4.25%, while the relationship between double bottom height and longitudinal spacing with structural weight is nonlinear due to the interaction of dimensional changes across various structural elements based on BKI scantling requirements. Based on these results, it can be concluded that the use of struts in a tanker's double bottom structure is able to improve stress distribution while achieving structural weight efficiency.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Berat, Metode Elemen Hingga, Strut, Tegangan, Finite Element Method, Stress, Strut, Weight.
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:	Azrul Mahastra Nasatya
Date Deposited:	01 Aug 2026 02:59
Last Modified:	01 Aug 2026 02:59
URI:	http://repository.its.ac.id/id/eprint/141740

Actions (login required)

View Item