A consistent approach for fluid-structure-contact interaction based on a porous flow model for rough surface contact

TL;DR

This paper introduces a novel continuum mechanical model incorporating surface microstructure effects for fluid-structure-contact interaction, coupled with a CutFEM numerical method capable of handling zero-gap contact scenarios.

Contribution

It presents a new physical model that includes surface roughness effects and a compatible numerical approach based on CutFEM for consistent fluid-structure-contact simulations.

Findings

Model captures surface microstructure effects on macroscopic response

CutFEM handles topological changes and zero-gap contact

Test cases demonstrate potential of the approach

Abstract

Simulation approaches for fluid-structure-contact interaction, especially if requested to be consistent even down to the real contact scenarios, belong to the most challenging and still unsolved problems in computational mechanics. The main challenges are twofold - one is to have a correct physical model for this scenario, and the other one is to have a numerical method that is capable of working and being consistent down to a zero gap. And when analyzing such challenging setups of fluid-structure interaction that include contact of submersed solid components it gets obvious that the influence of surface roughness effects is essential for a physical consistent modeling of such configurations. To capture this system behavior, we present a continuum mechanical model which is able to include the effects of the surface microstructure in a fluid-structure-contact interaction framework. An averaged representation for the mixture of fluid and solid on the rough surfaces, which is of major interest for the macroscopic response of such a system, is introduced therein. The inherent coupling of the macroscopic fluid flow and the flow inside the rough surfaces, the stress exchange of all contacting solid bodies involved, and the interaction between fluid and solid is included in the construction of the model. Although the physical model is not restricted to finite element based methods, a numerical approach with its core based on the Cut Finite Element Method (CutFEM), enabling topological changes of the fluid domain to solve the presented model numerically, is introduced. Such a CutFEM based approach is able to deal with the numerical challenges mentioned above. Different test cases give a perspective towards the potential capabilities of the presented physical model and numerical approach.