Why does a simulation involving contact using Calculix produce an over constrained system?

Using SimScale Solid Mechanics / FEA
1

For the Calculix users, when simulating a contact, often a common error is faced ‘At least one node is overconstrained for the current settings. Please check your boundary conditions for incompatible settings.’

To understand this better, we have created a documentation over it. Please take a look at the following link:

https://docs.simscale.com/docs/content/support/eventLogErrors/overconstrainedNode.html

A short summary is as follows:

  1. In a contact simulation, the nodes of the slave face cannot be constraint in any direction.
  2. Often there is a case that there are common nodes at the edges of two faces.
  3. If one face is slave and other has come constraint boundary condition applied, the above error is produced.
  4. The solution to this is presented in above link.

A round about way will be to use CodeAster instead of Calculix, if the user does not desire to make any CAD changes. :smile:

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