Dynamic Structure-Soil-Wave Model for Deep Water

A mathematical model has been developed for analyzing space-frame, offshore structures. The model, which is based on the normal mode approach, is amenable to either deterministic or stochastic forcing functions. Resistance of the soils to structural deflections is provided by means of a Winkler foundation. Natural frequencies and mode shapes of the restrained structures are the initial results. For harmonic wave forcing, the model produces complex structural deflections throughout the structures, and for random wave forcing, spectra of the structural responses are produced. The model has been used to investigate the response of a realistic offshore structure in a tropical storm. The results also indicate the importance of modeling the foundation as correctly as possible.