Stiffness Formulation of Flexible Bucket Foundation: a macro model approach

The response of offshore wind turbines e.g. static, eigen frequencies and eigen modes, are affected by elastic properties of the foundation and the subsoil. The Elastic Macro Model is developed to evaluate the soil-structure interaction of flexible bucket foundations for offshore wind turbines so that it can be properly included and analysed in a composite structure-foundation system. The typical approach for analysing the structure-foundation system is to use a finite-element method. Such an approach is, however, inefficient and time consuming. The Elastic Macro Model describes the foundation as a substructure with predetermined properties. The interaction between the foundation and structure is expressed purely in terms of force and moment resultants, and their conjugate displacements and rotations. The Macro Model modelling the Bucket Foundation is suitable for implementation in an internationally recognized aero-elastic code as e.g. HAWC or FLEX.