1. Safety of maritime operations - loads and responses.
Igor Rychlik

2. Outline of presentation
Introduction
Marine research in Chalmers
Environmental loads
Modelling significant wave height
Wave loads (Gaussian & non-Gaussian) WAFO
Responses (Linear & non-Linear)
Risk for capsizing
Ongoing projects

3. Marine research in Chalmers (SMT) Group of Jonas Ringsberg
Mathematical Sciences cooperate within I & IV.

4. 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

5. Simulation of encountered Hs:
2/24/20192/24/2019

6. 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

7. Ongoing projects (1)
No.1: fatigue routing and extreme estimation

8. Ongoing projects (2)
Investigate crossing of quadratic responses with Laplace Moving Average excitation
Thomas Galtier, joint PhD student Chalmers and UBS Vannes. IFREMER

9. 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

10. 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.