A DEM-FEM exploratory study on the mechanical interaction between lipid particles and the endothelial glycocalyx layer

Resumo

This work develops an exploratory study aiming at modeling (from a purely mechanistic point of view)
the complex interactions that are observed between the Endothelial Glycocalyx Layer (EGL) and Low-Density
Lipoprotein (LDL) particles, serving as a gateway to more complex studies about the transport of macromolecules

in arterial vessels. Here, the EGL is represented through an advanced finite element formulation for thin, large-
deformation beams, following a continuum description. The LDL particles, in turn, are handled through a discrete

element approach. The two phases (discrete and continuum) interact with each other through multiple contacts and
collisions, the forces and moments of which being thoroughly computed and passed from a discrete element (DEM)
to the finite element (FEM) model (and vice-versa) at run-time in a staggered, iterative solution scheme, following
the framework developed by the authors in Gay Neto and Campello [1] and Andreotti et al. [2]. The fluid (blood)
phase is represented only indirectly, through drag forces applied on both the FEM beams and DEM particles.
Possibilities of the proposed strategy are illustrated through a preliminary numerical example, herein taken in the
form of a model problem.