EMAIL: PASSWORD:
Front Office
UPT. PERPUSTAKAAN
Institut Teknologi Sepuluh Nopember Surabaya


Kampus ITS Sukolilo - Surabaya 60111

Phone : 031-5921733 , 5923623
Fax : 031-5937774
E-mail : libits@its.ac.id
Website : http://library.its.ac.id

Support (Customer Service) :
timit_perpus@its.ac.id




Welcome..guys!

Have a problem with your access?
Please, contact our technical support below:
LIVE SUPPORT


Moh. Fandika Aqsa


Davi Wahyuni


Tondo Indra Nyata


Anis Wulandari


Ansi Aflacha




ITS » Undergraduate Theses » Teknik Perkapalan
Posted by anis at 25/11/2008 17:19:50  •  5912 Views


ANALISA FREKUENSI ALAMI KAPAL BULK CARRIER

ANALYSIS OF NATURAL FREQUENCY OF A BULK CARRIER SHIP

Author :
Sujiatanti, Septia Hardy 




ABSTRAK

Getaran badan kapal yang disebabkan oleh eksitasi baling-baling dan permesinan dapat mengakibatkan kerusakan pada struktur kapal atau komponen-komponen penting permesinan menimbulkan efek yang tidak baik untuk kinerja peralatan dan perlengkapan penting di dalam kapal dan menambah ketidaknyamanan bagi penumpang dan crew kapal. Hal ini terjadi jika frekuensi eksitasi sama dengan frekuensi alami badan kapal atau terjadi resonansi. Secara umum baling-baling dan permesinan dalam hal ini adalah mesin induk kecepatan rendah adalah penyebab utama terjadinya resonansi. Dalam tugas akhir ini dilakukan studi kasus pada kapal Bulk Carrier 50000 DWT yang mengalami getaran. Perhitungan frekuensi alami dan mode shapes dilakukan dengan pemodelan analisa elemen hingga Finite Element Analysis menggunakan software ANSYS. Dan metode yang digunakan untuk penyelesaian adalah metode Block Lanczos default untuk menghitung frekuensi alami dan mode shapes untuk 90 mode yang pertama. Berdasarkan perhitungan frekuensi eksitasi baling-baling didapatkan 8.02 Hz untuk harmonik pertama. Untuk frekuensi eksitasi motor induk didapatkan 12.03 Hz untuk orde pertama. Hasil perhitungan dari running program ANSYS didapatkan frekuensi alami untuk mode pertama sampai dengan mode kesembilanpuluh berkisar antara 2.6171 Hz sampai dengan 36.544 Hz. Jika kondisi resonansi dianggap terjadi ketika frekuensi alami mendekati atau sama dengan frekuensi eksitasi baling-baling maka resonansi akan terjadi pada mode ke-18 pada getaran kapal. Resonansi juga akan terjadi pada mode ke-33 jika kondisi resonansi dianggap terjadi ketika frekuensi alami mendekati atau sama dengan frekuensi eksitasi motor induk. Akan tetapi jika kondisi resonansi dianggap terjadi ketika frekuensi alami berada antara 10 dari frekuensi eksitasi baling-baling maka resonansi akan terjadi antara mode ke-14 sampai dengan mode ke-21. Dan resonansi akan terjadi antara mode ke-31 sampai dengan mode ke-34 jika kondisi resonansi dianggap terjadi ketika frekuensi alami berada antara 10 dari frekuensi eksitasi motor induk.


ABSTRACT

Ships vibration which is caused by propeller and machinery excitation can cause fatigue failure of structural members or major machinery components adversely affect the performance of vital shipboard equipments and increase discomfort or annoyance to passengers and crew. It can occur if excitation frequency equal to natural frequency of ship or in a resonant condition. In generally the major sources of resonant are the low-speed diesel main engine and the propeller. In this Final Project the case study is done at the 50000 DWT Bulk Carrier ship which has got vibration. The calculation of natural frequency and mode shapes have been done by modelling of Finite Element Analysis using ANSYS software. And the method which is used to get solution is Block lanczos method as default method in ANSYS to calculate natural frequency and mode shapes at the first 90th modes. Based on the calculation excitation frequency of propeller is 8.02 Hz for the first harmonic. And excitation frequency of main engine is 12.03 Hz for the first order. The ANSYS programme gives the natural frequencies for the first mode up to the 90th modes are about 2.6171 up to 36.544 Hz. If resonant condition is assumed to occur when the natural frequency is nearly equal to the excitation frequency of the propeller resonance will occur at the 18th mode of vibration of the ship. The resonance will occur at the 33rd mode of vibration of the ship if resonant condition is assumed to occur when the natural frequency is nearly equal to the excitation frequency of the main engine. However if resonant condition is assumed to occur when the natural frequency is within 10 of the excitation frequency of the propeller resonance will occur between 14th up to 21st modes of vibration of the ship. And resonance will occur between 31st up to 34th modes of vibration of the ship if resonant condition is assumed to occur when the natural frequency is within 10 of the excitation frequency of the main engine.



KeywordsGetaran ; Frekuensi alami ; Resonansi ; Elemen hingga
 
Subject:  Kapal -- Model
Contributor
  1. Ir. Petrus Eko Panunggal, Ph.D
Date Create: 25/11/2008
Type: Text
Format: pdf.
Language: Indonesian
Identifier: ITS-Undergraduate-3100007030111
Collection ID: 3100007030111
Call Number: RSKe 623.824 5 Suj a


Source
Undergraduate theses, DEPARTMENT OF NAVAL ARCHITECT RSKe 623.824 5 Suj a, 2007

Coverage
ITS Community Only

Rights
Copyright @2007 by ITS Library. This publication is protected by copyright and permission should be obtained from the ITS Library prior to any prohibited reproduction, storage in a retrievel system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permission(s), write to ITS Library




[ Download - Summary ]

ITS-Undergraduate-3100007030111-2437.pdf




 Similar Document...




! ATTENTION !

To facilitate the activation process, please fill out the member application form correctly and completely

Registration activation of our members will process up to max 24 hours (confirm by email). Please wait patiently

POLLING

Bagaimana pendapat Anda tentang layanan repository kami ?

Bagus Sekali
Baik
Biasa
Jelek
Mengecewakan





You are connected from 54.160.187.160
using CCBot/2.0 (http://commoncrawl.org/faq/)



Copyright © ITS Library 2006 - 2016 - All rights reserved.
Dublin Core Metadata Initiative and OpenArchives Compatible
Developed by Hassan