• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.667-679
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• 2022

Fatigue damage analysis of ships includes parameters considering operational factors. Due to these operational variables, there is a difference between the fatigue damage estimated during the design stage and the actual accumulated fatigue damage. Likewise, there are various loading conditions for the real container ships, but at design stage the fatigue damage is calculated by applying the representative loading conditions. Moreover, although the difference in fatigue damages is expected when the actual and design loading conditions are applied, there are few studies on the contributions of the fatigue damage based on the loading conditions of container ships. In this paper, fatigue contributions were investigated from various cargo weight distributions. The hull girder loads calculated through seakeeping analysis and fatigue damages obtained by performing spectral fatigue analysis were identified under new loading conditions. As a result, it was found that the variation of cargo weight distribution in the container ship brought about changes in the hull girder loads and fatigue damage by affecting the hull girder stress.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.135-142
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• 2015

Floating offshore structures should be designed by considering the most extreme environmental loadings which may be encountered in their design life. The most severe loading on a wave-offshore wind hybrid power generation system is wave loads. The principal parameters of wave loads are wave length, wave height and wave direction. The wave loads have different effects on the structural behavior characteristic depending on the combination of wave parameters. Therefore, the process of investigation for critical loads based on the individual wave loading parameter is need. Namely, the equivalent design wave should be derived by finding the wave condition which generates the maximum stress in entire wave conditions. Through a series of analysis, an equivalent regular wave height can be obtained which generates the same amount of the hydrodynamic loads as calculated in the response analysis. The aim of this study is the determination of equivalent design wave regarding to characteristic global hydrodynamic responses for wave-offshore wind hybrid power generation system. It will be utilized in the global structural response analysis subjected to selected design waves and this study also includes an application of global structural analysis.