Required test durations for converged short-term wave and impact extreme value statistics–Part 2

Required test durations for converged short-term wave and impact extreme value statistics–Part 2: Deck box dataset

Scharnke, Jule (Maritime Research Institute Netherlands (MARIN))
van Essen, S.M. (TU Delft Ship Hydromechanics and Structures; Maritime Research Institute Netherlands (MARIN))
Seyffert, Harleigh C. (TU Delft Ship Hydromechanics and Structures)

2023

In the assessment of wave-in-deck loads for new and existing maritime structures typically model tests are carried out. To determine the most critical conditions and measure sufficient impact loads, a range of sea states and various seeds (realisations) for each sea state are tested. Based on these measurements, probability distributions can be derived and design loads determined. In air gap model testing usually only few, if any, impact loads occur per 3-hour seed. This can make it challenging to derive reliable probability distributions of the measured loads, especially when only a few seeds are generated. In addition wave impact forces, such as greenwater loading, slamming, or air gap impacts are typically strongly non-linear, resulting in a large variability of the measured loads. This results in the following questions: How many impacts are needed to derive a reliable distribution? How is the repeatability of individual events affecting the overall distribution? To answer these questions wave-in-deck model tests were carried out in 100 x 3-hour realisations of a 10,000 year North Sea sea state. The resulting probability distributions of the undisturbed wave measurements as well as the measured wave-in-deck loads are presented in this paper with focus on deriving the number of seeds and exposure durations required for a reliable estimate of design loads. The presented study is Part 2 of a combined study on guidance for the convergence and variability of wave crests and impact loading extreme values. The data set of Part 1 ([1]) is based on greenwater loads on a sailing ferry and the data set of Part 2 on wave-in-deck loads on a stationary deck box.

Convergence
Deck box
Experiments
Extreme value statistics
Offshore structure response
Seed variations
Short-term variability
Test duration
Wave impact loads
Wave-in-deck
Waves

http://resolver.tudelft.nl/uuid:240c32c8-157b-4ae0-af24-f9085ac0132d

https://doi.org/10.1016/j.marstruc.2023.103411

2023-09-09

0951-8339

Marine Structures, 90

Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

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© 2023 Jule Scharnke, S.M. van Essen, Harleigh C. Seyffert