Three Dimensional Numerical Modelling of Foundation Systems for Offshore Wind Energy Plants

Abstract: Offshore wind energy plants promise to become an important source of energy in the near future. It is expected that within 10 years, wind parks with a total capacity of thousands of megawatts will be installed in European seas. The foundation of such offshore wind energy plants plays an important role in the stability of these structures. High demands have to be made concerning foundation design and construction methods to find economical and technically optimal solutions. Two foundation concepts which can be used in this field are the monopile and the tripod. Regarding design practice and research in the field of the soil-structure-interaction the behaviour of these foundations could be covered using numerical modeling. A three-dimensional numerical model using the finite element system ABAQUS was developed. In this model the material behaviour of the subsoil is described using an elasto-plastic constitutive model with Mohr-Coulomb failure criterion. This material law was extended in the elastic range by a stress-dependency of the modulus of elasticity. To describe the real behaviour of the structure, the interactions between the foundation system and the surrounding soil are modeled using contact algorithm based on slave-master concept. The results of Finite Element simulations will be presented and evaluated