Fatigue routing of container ships – assessment of contributions to fatigue damage from wave-induced torsion and horizontal and vertical bending
Artikel i vetenskaplig tidskrift, 2012

The traditional method for assessing fatigue damage of ship structures assumes moderate wave amplitudes and linear responses. This method can be questioned when applied on container ships which are characterized by large deck openings that cause low torsion rigidity of the structure. Depending on the heading of the vessel in relation to wave encounter direction, container ships can therefore be sensitive to, for example, oblique waves. In the current investigation, the SESAM software with the three-dimensional hydrodynamic code WASIM is used to simulate a 4400 TEU container ship operating in the North Atlantic. Nonlinear wave loads are utilized for direct calculation of stress histories under severe sea states using the finite element software in SESAM. A method for the separation of normal stress components in an arbitrary cross section and location of the ship is proposed: warping stress from wave-induced torsion, and stress components from horizontal and vertical bending. The strain (stress) response calculated using the models in one location is verified against full-scale measurements made on a similar type of container vessel in the same location. A case study is presented for fatigue damage assessment in two cross sections of the container ship. The contributions to fatigue damage from wave-induced torsion and horizontal and vertical bending are calculated and presented in a fatigue damage routing tool by means of polar diagrams, which includes the effects of heading and ship speed on fatigue damage.

torsion

direct calculation

Container ship

fatigue

non-linear wave loads

fatigue routing

Författare

Zhiyuan Li

Chalmers, Sjöfart och marin teknik, Marine Design

Jonas Ringsberg

Chalmers, Sjöfart och marin teknik, Marine Design

Ships and Offshore Structures

1744-5302 (ISSN) 1754-212X (eISSN)

Vol. 7 119-131

Drivkrafter

Hållbar utveckling

Innovation och entreprenörskap

Styrkeområden

Transport

Materialvetenskap

Fundament

Grundläggande vetenskaper

Ämneskategorier

Tillförlitlighets- och kvalitetsteknik

Annan materialteknik

Farkostteknik

DOI

10.1080/17445302.2011.559368