Large deformation modelling of a plate anchor in marine clay based on micropolar continuum theory

Modelling anchor movement in marine clay presents significant challenges. Marine clay typically exhibits strain-softening behaviour, complicating traditional continuum models due to mesh dependency issues. Additionally, the clay surrounding an anchor undergoes significant geometric changes, leading to mesh distortion when using conventional finite element methods. To address these challenges, this paper introduces a mesh-independent micropolar finite element formulation integrated with the Remeshing and Interpolation Technique with Small Strain (RITSS) to investigate marine clay responses during anchor movement. The micropolar theory mitigates mesh dependency, while RITSS facilitates large deformation analysis. This study emphasises the selection of the internal length scale ( l c ) value to balance computational accuracy and efficiency and examines the influence of anchor embedment depth and clay strain-softening characteristics on failure modes and load–displacement responses. Notably, the findings demonstrate a linear relationship between the residual resistance force and the clay brittleness index. The results from this mesh-independent simulation offer valuable insights into the behaviour of marine clay under anchor loading conditions.