Plasticity Analysis of Plate Anchor Keying Process Considering an Integrated Anchor-Chain System

Abstract As offshore wind energy expands into deeper waters, the demand for efficient and reliable anchoring systems for floating structures continues to grow. Plate anchors are widely used due to their high holding capacity and cost-effective installation. However, the keying process—a critical phase where the anchor rotates and mobilizes its full capacity—often leads to embedment loss, reducing overall holding efficiency. Despite numerous studies, existing models typically assume a constant pullout angle at the mudline, neglecting the interaction between the anchor and the chain. This study presents an enhanced plasticity analysis framework to model the keying behaviour of plate anchors, integrating the continuous evolution of the chain tension within an anchor-line system. Unlike conventional approaches, the proposed model captures the variation of the mudline angle and its influence on anchor embedment. Additionally, the effects of chain length on anchor performance are investigated by simulating a new post-installation drag process with a moving vessel. The results reveal that longer chain lengths mitigate embedment loss, improving the overall efficiency of plate anchors. These findings provide valuable insights for optimizing anchor design and installation strategies in deep-water floating offshore wind applications.