Wave-in-deck loads: an assessment of present design practice given recent improvements in the description of extreme waves and the nature of the applied loads
File(s)
Published version
Author(s)
Ma, Li
Swan, Chris
Type
Journal Article
Abstract
This paper contributes to the on-going discussion of how best to calculate the reliability of a fixed offshores structure. This discussion has been driven, in large part, by improved physical understanding of waves arising in realistic design sea-states, with a growing appreciation that many ‘design wave events’ will be breaking, irrespective of water depth. As such, it is increasingly acknowledged that some aspects of present design practice are non-conservative. In re-assessing older structures, the accurate calculation of horizontal wave-in-deck (WID) loads is often the most important and least tractable part. This paper explains the underlying reason, highlights the wider implications for identifying an appropriate design point, and raises fundamental questions in the assumptions underpinning present practice. Specifically, a large laboratory data base of WID events is used to assess the success of available models. These comparisons confirm that recommended practice, including recent updates, consistently under-predict the maximum WID loads on which reliability calculations should be based. In contrast the recently developed Lagrangian Momentum Absorption (LMA) model (Ma and Swan, 2020b), a simple but complete load model that combines fully-nonlinear wave inputs and the openness/porosity of a structure, provides highly accurate predictions. This is achieved without empirical coefficients/calibrations and therefore ideally suited to design/re-assessment applications.
Date Issued
2023-10
Date Acceptance
2023-06-30
Citation
Ocean Engineering, 2023, 285 (Part 1), pp.1-19
ISSN
0029-8018
Publisher
Elsevier BV
Start Page
1
End Page
19
Journal / Book Title
Ocean Engineering
Volume
285
Issue
Part 1
Copyright Statement
© 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
http://dx.doi.org/10.1016/j.oceaneng.2023.115302
Publication Status
Published
Article Number
115302
Date Publish Online
2023-07-15