Analysis of Structural Second Order Effects on a Floating Concrete Platform for FOWT's

The model computes a dynamic time domain nonlinear FEA for FOWT's, integrating all the effects of the external forces and the structural stiffness to obtain the displacements at each point of the structure at each time step. With this approach, the dynamic interaction between the wind turbine and the structure, as well as the effects on the internal forces are implicitly considered in the formulation. A comparison of the structure motions and internal forces for a concrete spar concept is presented assuming a nonlinear rigid body approach and a nonlinear dynamic time-domain FEA.