Nonlinear Lid Technique: Application to Gap and Moonpool Resonance

This paper focuses on the implementation of a nonlinear Lid Technique, as done in the software Diodore™. Several dummy plates are used and modelled as mechanical structures with their own degrees of freedom, capable to account for nonlinear damping. The paper describes first the general equations governing the multi-body sea-keeping model including dummy plate structures, and the expression of the relative quadratic damping. In a second step, examples of applications with gap and moonpool are exposed, demonstrating the capability of the nonlinear Lid Technique with multiple plates to render not only the piston mode, but also the other modes of deformation of the free surface.