Virtual testing of sand for offshore wind foundation design
The main objective of the thesis is to apply the level set discrete element method to simulate cyclic sand behaviour and validate the results against experimental data.
Offshore wind (OW) energy is rapidly growing, with wind turbines installed in increasingly challenging locations. One of the bottlenecks of the OW industry is the limited capacity of the site investigation vessels.
The laboratories to process and test soil samples and the proposed research topic is especially motivated by an urgency to characterize the ground conditions to design wind turbine structures more efficiently.
This thesis aims to apply the level set discrete element method (LS-DEM) to simulate "virtual" cyclic tests on the sand and validate the results against experimental data.
The LS-DEM is a powerful numerical method that can simulate the behaviour of granular materials on the particle scale with high accuracy and efficiency. The LS-DEM combines level set functions, which are used to define the shape of the particles, e.g., obtained from CT scanning, and the discrete element method, which simulates the interactions between the particles. The LS-DEM has been successfully used in various applications, such as geotechnical engineering, mining, and pharmaceuticals.
This master thesis will be conducted with NorthWind – the Norwegian Research Centre on Wind Energy. This centre is a strategic research cooperation co-financed by the Research Council of Norway, industry, and research partners.
SINTEF heads the Centre in close collaboration with research partners NTNU (Norwegian University of Science and Technology), UiO (University of Oslo), NGI (Norwegian Geotechnical Institute) and NINA (Norwegian Institute for nature research).
The main objectives of this thesis are:
- To develop a numerical model using LS-DEM to simulate the cyclic behaviour of Dogger Bank sand under loading conditions representative of offshore wind turbine foundations.
- To compare results from the numerical model against experimental data from the literature and in-house (e.g., cyclic contour diagrams) and evaluate possible shortcomings with the model.
- To apply the outcome of the virtual tests to study the performance of a gravity base foundation for offshore wind turbines.
