The random environment of offshore systems

The analysis of the dynamical behavior of systems in ocean waves is an important part in offshore engineering. While a characterization of the response of a linearized model can be obtained in frequency domain, it has to be noted that offshore systems usually include components with nonlinear behavior. The systematic analysis of the nonlinear dynamics of floating structures is often facilitated by additional assumptions. One common example is the use of deterministic (harmonic) waves. Even though periodic waves may be a reasonable simplification for many applications, sea waves in general are usually better described by a spectral or probabilistic approach. This paper addresses different methods of describing random forces for the analysis of floating structures. Examples show the effects of different wave models on the analysis of a simple floating structure.