Study of Springing Effect on Large Container Vessel
Date Issued
2014
Date
2014
Author(s)
Liao, Po-Kai
Abstract
This study employs modal superposition method to conduct hydro-elastics analysis, and evaluates stress distribution on ship structure considering springing effect. With the calculated stress response amplitude operators (RAO), spectral fatigue analysis (SFA) is used to obtain the fatigue life of hot spot on ship structure.
Springing effect is the phenomenon of ship hull structure resonance induced by wave load, which will cause extra cyclic loads on ship structure, therefore, fatigue life of ship would be decreased. The natural frequency of ship structure becomes lower while the size of container vessel growing larger and the widely use of high tensile steels are applied considerably, thus it is more probable to have the encounter frequency of wave loads approaching the natural frequency of ship hull structure, which makes springing an important subject in large container vessel design.
This study considered the CSBC’s 8,000TEU container vessel with two different loading conditions. A spectral approach using hydroelastic software Homer and Springing tools which contributed by Bureau Veritas has been used to evaluate the springing effect. To perform spectral fatigue analysis, the stress RAOs of hot spot which obtained by FE analyses were further combined with the wave scatter diagram. Two hotspot positions were chosen to compare their fatigue lives with/without springing effect. In the spectral fatigue analyses, two different wave scatter diagrams and two ship speeds were also considered as parameters in order to compare springing effects under different operating conditions.
Springing effect is the phenomenon of ship hull structure resonance induced by wave load, which will cause extra cyclic loads on ship structure, therefore, fatigue life of ship would be decreased. The natural frequency of ship structure becomes lower while the size of container vessel growing larger and the widely use of high tensile steels are applied considerably, thus it is more probable to have the encounter frequency of wave loads approaching the natural frequency of ship hull structure, which makes springing an important subject in large container vessel design.
This study considered the CSBC’s 8,000TEU container vessel with two different loading conditions. A spectral approach using hydroelastic software Homer and Springing tools which contributed by Bureau Veritas has been used to evaluate the springing effect. To perform spectral fatigue analysis, the stress RAOs of hot spot which obtained by FE analyses were further combined with the wave scatter diagram. Two hotspot positions were chosen to compare their fatigue lives with/without springing effect. In the spectral fatigue analyses, two different wave scatter diagrams and two ship speeds were also considered as parameters in order to compare springing effects under different operating conditions.
Subjects
波振效應
流固耦合
水彈性力學
疲勞壽命
頻譜疲勞分析
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-103-R01525016-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):4d8f9de6e2eab884469644a61f6066fb