Reset displacement after the equilibrium with Neumann stress boundary conditions

Hi all, I am trying to realize the poro-elastic equilibrium by applying stress boundary conditions gradually because in my personal branch I don’t use an accumulative method for the calculation of stress so that the tag initial_stress doesn’t make sense. Now the stress has been applied in the whole domain successfully but there is also displacement brought by the equilibrium. I want to know if there are some methods to remove the initial displacement so that I can do the following simulation with a zero displacement but mentaining the initial stress at the beginning. Thank you very much!


you can do it with a restart. With the restart, you can set all variables to the final values of the previous simulation, except for the displacement that you set to zero with a constant parameter as IC value.
Care must be taken with the integration point data:

  • With older branches, you need to delete ‘epsilon_ip’ integration point data of the mesh file (of the final step of the previous simulation) you read in
  • with more recent versions of ogs, you need to add ‘sigma_ip’ and ‘IntegrationPointMetaData’ in the previous run in order to perform the restart correctly.

One tip that might be useful as well: you can reach mechanical equilibrium also by setting stress and compensating the non-equilibrium in the momentum equation: OGS: [tag] compensate_non_equilibrium_initial_residuum

Thank you very much. I will try the way you suggested. :nerd_face: