Error in thermal contact based mortar

[jin0123456]

Hello,

I met the error in mortar thermal contact,
The requested mortar interface AutomaticMortarGeneration object does not yet exist!
And i find it in MortarData.C line 123 and 145,
https://github.com/idaholab/moose/blob/61714043f0e9dcbf822da0b852b47ef2c6a08ae2/framework/src/constraints/MortarData.C

const AutomaticMortarGeneration &
MortarData::getMortarInterface(const std::pair<BoundaryID, BoundaryID> & boundary_key,
                               const std::pair<SubdomainID, SubdomainID> & /*subdomain_key*/,
                               bool on_displaced) const
{
  if (on_displaced)
  {
    if (_displaced_mortar_interfaces.find(boundary_key) == _displaced_mortar_interfaces.end())
      mooseError(
          "The requested mortar interface AutomaticMortarGeneration object does not yet exist!");

    return _displaced_mortar_interfaces.at(boundary_key);
  }
  else
  {
    if (_mortar_interfaces.find(boundary_key) == _mortar_interfaces.end())
      mooseError(
          "The requested mortar interface AutomaticMortarGeneration object does not yet exist!");

    return _mortar_interfaces.at(boundary_key);
  }
}

I want to know about _displaced_mortar_interfaces.find(boundary_key) == _displaced_mortar_interfaces.end(),
what's this about? Where is my problem and how can i fix it?

[GiudGiud]

Hello

What's missing is that createMortarInterface has not been called beforehand on that interface (two boundaries)
Are you developing or this is straight from a moose input with regular objects?

Guillaume

[jin0123456]

I found out the reason. If I set use_displaced_mesh = true in ModularGapConductanceConstraint object I will get the error or I will not.
So I want to know why would this happen? What is this setting about?
In my case, the deformation of the mesh is relatively large and the distance between two boundaries will decrease during simulation.
How should I use use_displaced_mesh? Should I set true or false?

[GiudGiud]

@recuero

[recuero]

It may be the the user is just missing the creation of the lower dimensional domains? Almost positive MOOSE have examples of these heat transfer mortar constraints with displaced meshes, maybe through actions.

[jin0123456]

I know what i should do now. Much appreciated!