Estimation of Extreme Ship Response
Journal article, 2012

In practice the severity of ship response is measured by high quantiles of long-term distribution of the response. The distribution is estimated by combining the short-term distribution of the response with a long-term probability distribution of encountered sea states. The paper describes an alternative approach, the so-called Rice’s method, based on estimation of expected number of upcrossings of high levels by stress during 1 year. The method requires description of long-term variability of the standard deviation, skewness, kurtosis, and zero upcrossing frequency of ship response. It is assumed that the parameters are functions of encountered significant wave height, heading angle, and ship speed. The relation can be estimated from the measured stresses or computed by dedicated software assuming rigid ship hull model. Then Winterstein’s transformed Gaussian model is used to estimate the upcrossing rates of response during a sea state. The proposed method is validated using the full-scale measurements of a 2,800 TEU container ship during the first 6 months of 2008. Numerical estimation of 4,400 TEU container ship extreme response illustrates the approach when no measurements are available.

extreme response

waves

long-term distribution

Author

Wengang Mao

Chalmers, Mathematical Sciences, Mathematical Statistics

University of Gothenburg

Igor Rychlik

University of Gothenburg

Chalmers, Mathematical Sciences, Mathematical Statistics

Journal of Ship Research

0022-4502 (ISSN)

Vol. 56 1 23-34

Driving Forces

Sustainable development

Areas of Advance

Transport

Energy

Roots

Basic sciences

Subject Categories

Other Materials Engineering

Probability Theory and Statistics

Learning and teaching

Pedagogical work

DOI

10.5957/JOSR.56.1.100032