Catalog data:
Ship vibrations, noise, measuring of vibrations, design philosophy, propeller excitation,
vibration modes. |
Courseyear:
3
Semester: 6/0/0/0
Hours p/w: 6
Other hours: -
Assessment: Written
Assessm.period(s): 1, 2
(see academic calendar) |
Prerequisites:
mt827, mt110, mt111,
mt214, mt211, mt511. |
Follow
up: mt814, mt212, mt213, mt515. |
Detailed
description of topics:
General vibration theory is introduced and applied
to the ship as a slender beam. Solutions for the first and higher mode vibrations are
presented. Excitation is by internal sources (main engine), the propeller as well as wave
action. A description is given of the added mass of the surrounding water. Measuring
vibrations and interpretation of the results is described. Noise, sources of noise,
transmission routes and criteria for acceptance of noise levels. Inclusion of noise and
vibration considerations on the design of the vessel.
Further to the course mt 827 failure modes and ultimate strength of the
structure are considered. Fatigue, crack propagation and brittle fracture
play an important role. These aspects are dealt with both in a fundamental
way as using practical standard design procedures. The implications of
these aspects for the structural design of ships and their details are
taught. The structural design can be made in a deterministic as well as
probabilistic way. Attention is given to measurements at sea and hull
monitoring. Characteristics of the main structural material for ships,
i.e. steel, are described and the methods to influence them. Fabrication
methods (in particular welding) have a major impact on material properties
and consequently the safety of the structure.
|
Course
material:
Lecture notes
|
References
from literature:
"Noise, vibration and shock on board
ships", 16th WEGEMT Graduate School, Genoa, 1992.
Pettersen, J.W.E. (ed.), Storm, J.Fr. (ed.):
"Noise control in ships", Oslo 1975, ISBN 82-7174-071-7.
"Vibration control in ships", Oslo 1985,
ISBN 82-515-0090-7.
J.R. Paulling: Strength of Ships, in E.V. Lewis
(ed.): Principles of Naval Architecture, 2nd ed., ISBN 0-939-773-00-7.
D.W. Chalmers: Design of Ships' Structures, HMSO
London, 1993, ISBN 0 11 772717 2.
O.F. Hughes: Ship Structural Design, SNAME, 1988,
ISBN 0-939773-04 X.
K.J. Rawson, E.C. Tupper: Basic Ship Theory, part 1,
4th ed., Longman.
R. Taggart (ed.): Ship Design and Construction,
SNAME, 1980, ISBN 0-9603048-0-0.
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Remarks
(specific information about assesment, entry requirements, etc.): |
Goals:
The course aims to give the students understanding
of the importance of vibrations and noise on board ships, the sources of noise and
vibrations and the means to reduce the effect. Also they learn how to measure noise and
vibration and how to interpret the results. They are taught how to include the impact of
noise and vibration in the design.
|
Computer
use: |
Laboratory
project(s):
Part of the laboratory experiments mt 823P is
measuring vibrations of a cantilevered beam with varying end mass and the vibration
behaviour of a beam in air and in water.
|
Design
content:
The impact of noise and vibration considerations on
ship design is part of the course.
|
Percentage
of design: 40% |