[petsc-users] GAMG failure

Blaise Bourdin bourdin at mcmaster.ca
Fri Mar 24 13:07:08 CDT 2023


I am having issue with GAMG for some very ill-conditioned 2D linearized elasticity problems (sharp variation of elastic moduli with thin  regions of nearly incompressible material). I use snes_type newtonls, linesearch_type cp, and pc_type gamg without any further options. pc_type Jacobi converges fine (although slowly of course).

I am not really surprised that gamg would not converge out of the box, but don’t know where to start to investigate the convergence failure. Can anybody help?


Canada Research Chair in Mathematical and Computational Aspects of Solid Mechanics (Tier 1)
Professor, Department of Mathematics & Statistics
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https://www.math.mcmaster.ca/bourdin | +1 (905) 525 9140 ext. 27243

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