The nonlinear 3-dimensional finite element (FE) program, named INFIDEP, is a computationally efficient, robust and accurate tool for optimized design of offshore wind turbine (OWT) foundations. INFIDEP can be used to calculate the displacements and rotation of the foundation, structural forces, soil reactions against the foundation and hysteretic damping in the soil during cyclic loading. The paper presents the FE formulation, solution algorithm and material models together with example calculations of two different foundation types. The results are compared with results obtained by the commercial finite element programs PLAXIS 3D and Abaqus. In addition, a comparison against one of the test data at the Cowden test site from the PISA project is presented. The calculation time by INFIDEP is reduced in the order of 100 compared to PLAXIS 3D for the cases considered in this paper and the tool can therefore be used directly in the optimized design of OWT foundations.
Nallathamby Sivasithamparam and Hans Petter Jostad
Keywords: efficient FEA, nonsymmetric behaviour, wind turbine foundations, monopile, GBS
Publisher: DFI