Establishing AEM structural framework within SPH-MBD coupling for hydro-viscoelastic response of very flexible floating structures

Very Flexible Floating Structures (VFFS), deployed into offshore environments by the renewable energy sector, have set the ground for new marine applications. Characterized by very thin and elongated structural layouts, while composed of highly flexible materials, they exhibit non-linear structural behaviour when subjected to wave-induced loads. To numerically predict their hydro-viscoelastic response, the Applied Element Method (AEM), commonly used in non-linear structural dynamics, is introduced into the existing coupling scheme of the Smoothed Particle Hydrodynamics (SPH) solver, DualSPHysics, and the Multibody Dynamics (MBD) module of Project Chrono. In this paper, the coupling scheme is modified to implicitly define the timestep of Project Chrono, facilitating the development of AEM formulated structures. The structural response accuracy of the proposed framework is validated against analytical and experimental data in both dry and wet conditions, covering linear and non-linear deformations, as well as elastic and viscous material properties. Fluid response is also verified through wave reflection and wave dissipation, demonstrating the suitability of the developed numerical framework for modelling non-linear fluid-flexible structure interaction applications.