A coupled high-accuracy phase-field fluid-structure interaction framework for Stokes fluid-filled fracture surrounded by an elastic medium
Henry von Wahl, Thomas Wick
TL;DR
This paper introduces a fully coupled framework that combines a high-accuracy phase-field fracture model with an ALE-based fluid-structure interaction solver for a Stokes flow inside a fluid-filled crack surrounded by an elastic medium. The key advance is to switch from interface-capturing to interface-tracking via mesh reconstruction, enabling sharp interface conditions to be imposed on the crack boundary and a reconstructed open crack domain for the FSI problem. The authors formulate a pressurized phase-field fracture problem with explicit interface terms, solve it iteratively with an open-crack domain reconstruction, and couple to a Stokes FSI problem with averaged crack pressure feeding back into the phase-field model. Numerical tests on Sneddon-type configurations and propagating cracks demonstrate accurate COD/TCV convergence and qualitatively correct fracture evolution under stationary and quasi-static loading; the work provides a path toward fully time-dependent, multi-physics fracture simulations. The approach has potential applications in subsurface and biomedical contexts where accurate interface conditions and evolving fracture geometry are critical.
Abstract
In this work, we couple a high-accuracy phase-field fracture reconstruction approach iteratively to fluid-structure interaction. The key motivation is to utilize phase-field modelling to compute the fracture path. A mesh reconstruction allows a switch from interface-capturing to interface-tracking in which the coupling conditions can be realized in a highly accurate fashion. Consequently, inside the fracture, a Stokes flow can be modelled that is coupled to the surrounding elastic medium. A fully coupled approach is obtained by iterating between the phase-field and the fluid-structure interaction model. The resulting algorithm is demonstrated for several numerical examples of quasi-static brittle fractures. We consider both stationary and quasi-stationary problems. In the latter, the dynamics arise through an incrementally increasing given pressure.
