Estimation of Extreme Roll Motion Using the First Order Reliability Method

Ju-hyuck Choi*, Jørgen Juncher Jensen, Ulrik Dam Nielsen

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

Abstract

Extreme value statistics can often be based on the assumption that exceedance events of a high threshold level are statistically independent and identically distributed (i.i.d. process), which further implies the Poisson assumption to be valid. This makes it possible to express the extreme response statistics through the mean up-crossing rate. For non-linear processes, analytic expressions of the mean up-crossing rate do not in general exist. Reliable statistics of mean up-crossing rate based on the brute-force approach, e.g. Monte Carlo simulation (MCS) require long time domain simulations considering a number of different ensemble input. The associated computations can be very time consuming especially when a detailed physical (e.g. hydrodynamic) model is applied. The First Order Reliability Method (FORM) has previously been found efficient for estimation of extreme value prediction of stationary stochastic time domain processes, However, if the non-linearity in a response is significant, the accuracy of the FORM linearized mean up-crossing rate can be limited. The present work attempts to improve the extreme value prediction for nonlinear parametric roll motions of ships based on applications of the FORM approach and suggests a model for the mean up-crossing rate for strong non-linear response, validated by comparing with MCS results.
Original languageEnglish
Title of host publicationProceedings of the 14th International Symposium on Practical Design of Ships and Other Floating Structures (PRADS 2019)
PublisherSpringer
Publication statusAccepted/In press - 2020
EventThe 14th International Symposium on Practical Design of Ships and Other Floating Structures (PRADS 2019) - Yokohama, Japan
Duration: 22 Sep 201926 Sep 2019

Conference

ConferenceThe 14th International Symposium on Practical Design of Ships and Other Floating Structures (PRADS 2019)
CountryJapan
CityYokohama
Period22/09/201926/09/2019

Keywords

  • Extreme value statistics
  • Poisson up-crossing
  • Intact stability of ships

Cite this

Choi, J., Jensen, J. J., & Nielsen, U. D. (Accepted/In press). Estimation of Extreme Roll Motion Using the First Order Reliability Method. In Proceedings of the 14th International Symposium on Practical Design of Ships and Other Floating Structures (PRADS 2019) Springer.