Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Modeling of fatigue in RORO ships
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
2012 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

The largest modern Pure Car and Truck Carriers (PCTC’s) are typically 230 meters long and have 13 cargo decks. In order to facilitate rapid loading and unloading these ships have been subject to a development of reducing any obstructing structures in the cargo hold, meaning that the transversal shear preventing structures, i.e. the racking bulkheads, has been taken to a minimum. Previous studies have concluded that some points on the racking bulkheads, as a result of the stripped down design, are subject to high stresses resulting from wave induced accelerations of the ship.

In this M.Sc. Thesis the fatigue life of a corner of a transverse bulkhead opening in a 230 meter long PCTC with a capacity of 7200 cars is calculated with different methods.

•Fatigue life is calculated from recorded ship motion data with the notch stress method in conjunction with rain flow counting and the cumulative damage principal.

• Fatigue life is calculated according to (DNV CN. 30.7, 2010), based on a Lloyd’s Register FE model load case.

• Actual findings on the ship are compared to the calculated results. Due to the lack of inspection data this comparison is not very extensive and only more briefly discussed.

It is concluded that the fatigue life of the examined point, calculated from recorded motion data is 9.6 years and the fatigue life according to DNV is 8.0 years. It is also found that the fatigue damage is cumulated in almost discrete portions and thus the calculated fatigue life can be inaccurate when a short period of time is evaluated as is done in this thesis.

A modification to the racking bulkhead with respect to fatigue life is also analyzed and it is concluded that the fatigue life in the examined point could be extended significantly by some simple modifications to the geometry.

Place, publisher, year, edition, pages
2012. , 53 p.
Series
Trita-AVE, ISSN 1651-7660 ; 2012:88
National Category
Vehicle Engineering
Identifiers
URN: urn:nbn:se:kth:diva-119767OAI: oai:DiVA.org:kth-119767DiVA: diva2:612290
Subject / course
Naval Systems
Uppsok
Technology
Examiners
Available from: 2013-03-21 Created: 2013-03-21 Last updated: 2013-03-21Bibliographically approved

Open Access in DiVA

fulltext(11699 kB)520 downloads
File information
File name FULLTEXT01.pdfFile size 11699 kBChecksum SHA-512
bdf9d9ca5a07be74f7225ebbe5f53c0e6c6fd1c58a36f61aa2ce08a7a7d7f40a17c59ee6f965129a699b3f2496ae99597e399204b567bf5fb2863650c18f5d98
Type fulltextMimetype application/pdf

By organisation
Naval Systems
Vehicle Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 520 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 515 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf