Matrix-Free Geometric Multigrid Preconditioning Of Combined Newton-GMRES For Solving Phase-Field Fracture With Local Mesh Refinement
Leon Maximilian Kolditz, Thomas Wick
TL;DR
The paper develops a matrix-free, locally refined Geometric Multigrid preconditioned GMRES framework for solving the inner linear systems arising in a quasi-static phase-field fracture model with crack irreversibility enforced via a primal-dual active set method. It combines a line-search Newton solver with a matrix-free GMG preconditioner on locally refined meshes to efficiently handle the coupled displacement $u$ and phase-field $\varphi$ variables, including the inequality constraint. Key contributions include the integration of a Chebyshev-Jacobi smoother, a robust transfer of the active set across multigrid levels, and a fully matrix-free deal.II implementation. Numerical tests on Sneddon’s benchmark demonstrate convergence toward reference solutions with mesh refinement and robustness of the linear solver, despite occasional spikes tied to active-set predictions.
Abstract
In this work, the matrix-free solution of quasi-static phase-field fracture problems is further investigated. More specifically, we consider a quasi-monolithic formulation in which the irreversibility constraint is imposed with a primal-dual active set method. The resulting nonlinear problem is solved with a line-search assisted Newton method. Therein, the arising linear equation systems are solved with a generalized minimal residual method (GMRES), which is preconditioned with a matrix-free geometric multigrid method including geometric local mesh refinement. Our solver is substantiated with a numerical test on locally refined meshes.
