Modelling structural performance of offshore wind turbine support structures in ice-infested waters by using design load portal

The Gulf of Bothnia has the potential for large capacity wind farms because of relatively high and constant wind velocities. The mostly shallow coastal areas enable cost-efficient foundation and grid connection. However, the sea freezes annually, introducing the most significant uncertainties in the support structure design for offshore wind turbines. Drifting ice introduces major design load case for offshore wind turbines. The magnitude and time variation of the sea ice load depends on various factors like the thickness and velocity of the ice as well as the size and shape of the structure. Dynamic coupling between the ice and structural deformations at water line needs to be considered to model ice actions.
This presentation introduces an ice load portal that simplifies and speeds up the preliminary design process for offshore wind farms. The design portal integrates all necessary information (site-specific environmental data, structural design, and environmental loads) into a single tool. This study demonstrates the functionality of the ice load design portal with case studies. Two various coupled ice-structure interaction models: the Määttänen-Blenkarn model and the Sodhi model were applied. The model validation was made by case studies of two various sites including comparisons to commercial FEM software (Abaqus). As each simulation takes only few minutes to run, the portal can be used iteratively with low computational costs. If the solution does not fit the design requirements, the user can straightforwardly change the site and/or the structure and run the analyses again. This procedure can easily be repeated as many times as necessary.
As the design portal integrate all necessary information (site-specific environmental data, structural design and environmental loads) into a single tool, it shortens the preliminary design process for offshore wind farms.