NON-LINEAR ANALYSIS OF LARGE-AMPLITUDE ROLLING EXPERIMENTS

Abstract

Various methods for analyzing large-amplitude forced roll and roll decrement experiments in calm water are described and compared. The methods are suitable for determining the nonlinear damping coefficients of a model. The methods for forced roll tests are predicted upon the model's rolling freely under the influence of a sinusoidal exciting moment, and all the methods use only the peaks of the roll angle response. Techniques for assessing the accuracy of the different analytical methods and reasons for differences in the results of the various methods are presented.