Enhancement of a high‐cycle accumulation model by an adaptive strain amplitude and its application to monopile foundations

The high-cycle accumulation (HCA) model by Niemunis et al. allows the prediction of mechanical response sand under millions load cycles . It has originally been developed with focus on drained high-cyclic loading assuming a constant strain amplitude, which can be periodically updated. In order to apply it for partially or fully undrained conditions, an adaptive definition amplitude is proposed in this work. extension taking into account influence rapid changes soil stiffness as encountered, example, case large effective stress during loading. Two approaches are presented update amplitude: ‘private’ each integration point combined nonlocal smoothing algorithm and separate analysis performed parallel simulation using HCA model. Both compared methodology used previous work employing so-called cycles. importance advantages modifications demonstrated cyclic triaxial tests monopile foundations offshore wind turbines (OWTs) lateral conditions.