Abstract
This paper presents a cross spectral stochastic analysis methodology for the determination of the combination of global wave-induced dynamic loads by taking into account uncertainties associated with the wave heading, the joint probabilities of the wave environment and the correlations between different global wave-induced dynamic loads. The methodology considers the use of bivariate probability density functions (the cross-spectral probabilistic approach) or the co-variances of two random variables with their associated derivatives (the cross-spectral Hamilton's method) and assumes only rigid body hydrodynamic actions under steady forward speed conditions. The design extreme values of principal global wave-induced load components and their combinations for a container ship progressing in irregular seaways are predicted using these two cross-spectral methods together with the short-term and long-term statistical formulations. It is shown that in general terms both cross-spectral analysis methods can be employed to assess the effects of loads in ship design and reliability analysis. However, the cross-spectral Hamilton's method predicts slightly higher load combinations than the cross-spectral probabilistic approach.
Original language | English |
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Pages (from-to) | 131-151 |
Number of pages | 21 |
Journal | Marine Structures |
Volume | 29 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Dec 2012 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Cross-spectral analysis
- Global wave-induced loads
- Loads combination