ASSESSMENT OF SHIP'S TRANSVERSE STABILITY AT SEA

Abstract The main objective of this paper is to present the application of the random decrement technique to nonlinear ship roll motion. The validity, accuracy and reliability of the method are investigated using model experimental and full-scale ship test data. The predicted natural frequency obtained using either the random decrement or autocorrelation function method can be used to determine the value of the metacentric height for a ship rolling under the action of unknown random excitation. Since the random decrement method does not require the measurements of wave height, and roll motion of a ship can be easily measured in a seaway, it is expected that the method would be particularly useful for the determination of the transverse stability of a ship sailing in a realistic sea.