The Performance of Suction Caissons for Floating Offshore Wind Turbines under Inclined Cyclic Survival Loads

This paper assesses the design consideration of suction caisson for floating offshore structures by fulfilling the serviceability limit state (SLS) concerning the long-term deformation which would involve the influences of cyclic loadings for a long time on the caisson life-time. The accumulative deformation inspection is a significant issue regarding caissons design and particularly under cyclic loading. Therefore, reasonable estimates of the accumulative plastic displacements of suction caisson anchors in cohesive soils under an inclined cyclic force of the mooring line are presented. Results are presented in terms of both vertical and lateral accumulative displacements profiles. A parametric study is studied in which the effects of inclined load angle, cyclic amplitude, and soil stiffness is evaluated. The analyses have been contemplated with soil nonlinearity under cyclic loading where a bounding surface plasticity model is required. An axisymmetric finite element analysis has been utilized with the asymmetric Fourier elements to simulate the behavior of a suction caisson in clay using the software program ABAQUS.