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Safety of maritime operations - loads and responses. Igor Rychlik. Outline of presentation. Introduction Marine research in Chalmers Environmental loads Modelling significant wave height Wave loads (Gaussian & non-Gaussian ) WAFO http://www.maths.lth.se/matstat/wafo/
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Safety of maritime operations - loads and responses. Igor Rychlik
Outline of presentation • Introduction • Marine research in Chalmers • Environmental loads • Modelling significant wave height • Wave loads (Gaussian & non-Gaussian) WAFO http://www.maths.lth.se/matstat/wafo/ • Responses (Linear & non-Linear) • Risk for capsizing • Ongoing projects
Marine research in Chalmers (SMT) Group of Jonas Ringsberg Mathematical Sciences cooperate within I & IV.
Researches on environmental models • Models of Sea state variability • Model for the mean value of Hs = 2/365.2 ; Xt(p) = ln(Hs(p)); p=(p1,p2), position; t – time. • Model for the covariance function of X(p,t) and • encountered Hs; z(t)=X(p(t),t). • Application: Estimates of 100-year Hs
Wave loads and responses • Fatigue and extreme responses • Wave loads (Gaussian & Second order model) • Structural responses linear, quadratic filters Gaussian and non-Gaussian input • Goal: Estimation of design values (extreme) and fatigue life • Uncertainty analysis
Ongoing projects (1) No.1: fatigue routing and extreme estimation
Ongoing projects (2) • Investigate crossing of quadratic responses with Laplace Moving Average excitation • Thomas Galtier, joint PhD student Chalmers and UBS Vannes. IFREMER
Ongoing projects (3) • Investigation of fatigue in ship details and estimation of extreme responses • Non-Gaussian stress models (spectrum, skewness, kurtosis) • Structural analysis and stochastic models gives parametric function of operation conditions
Ongoing projects (4) • Chasing uncertainties Uncertainties in material related parameters Chaos expansion for parameters in models (wave loads and responses) Variability of load condition • For North Atlantic DNV uses 3 parameter Weibul model • The DNV model gives about 50% smaller expected damage per sea state then observed. Another methods are needed. We use more detailed model for Hs variability, presented before.