Spar Floating Platform: Numerical Analysis and Comparison with Data

Second-order nonlinear models have been increasingly used in recent years to model nonlinear processes in offshore engineering. We apply such models to study the global responses of a spar floating platform. Traditional linear models of wave loads on offshore structures tend to be inaccurate in the response predictions. Second-order nonlinear models although computationally more expensive provide an opportunity to better predict these loads. Recent tests conducted on a spar floating platform offer wave tank data for extreme conditions in both the Gulf of Mexico and the North Sea. We model the tested spar floating platform as a linear rigid-body with 6 degrees of freedom. The incident wave loads are modeled as a second-order phenomenon. Of interest is the global response of the spar, which here is the total horizontal displacement near the spar deck. Although the apparent transient response and the few measured response cycles pose difficulties in calibrating the model, we find the model to offer reasonable predictions when compared to the measured results in wave tanks.