Large-deformation numerical simulation of bucket foundation penetration based on combined ALE-RITSS method

The mechanical behavior of offshore wind turbine bucket foundations during penetration is often investigated via large-deformation finite element numerical simulations. However, the thin-walled structure and deep penetration characteristics of steel bucket foundations pose significant challenges for traditional large deformation finite element methods. This paper proposes a combined ALE (Arbitrary Lagrangian-Eulerian)-RITSS (Remeshing and Interpolation Technique with Small Strain) method tailored for axisymmetric quasi-static penetration problems of such foundations. On the basis of the conventional ALE framework, the proposed method incorporates the core idea of RITSS, employing periodic model reconstruction and variable mapping to effectively avoid numerical termination caused by mesh distortion under extremely large deformation conditions. The results demonstrate that the combined ALE-RITSS method can accurately predict the penetration resistance of offshore wind turbine bucket foundations while significantly enhancing computational efficiency.