Hinged boundary condition

question about hinged boundary condition, for example a beam hinged at both ends. It would be done with Boundary Conditions - Fixed Support, and then fixing only nodes along a line. But how can I select edges or nodes? It seems only surfaces are selectable.
Moreover I see (when exporting the mesh and transfering to .med-format which I m more familiar with) that the mesh contains only solid (tetra) and face (3angle) elements but no line elements which should be selected for a hinge condition

thank you, and regards

Johannes_ACKVA
www.code-aster.de

Hi Johannes, this is Fillia!

As you mentioned correctly, it is not possible to select and assign boundary conditions to edges and nodes, only to faces :slight_smile: Would assigning a whole face as fixed support work for you instead, like in this case for example: Fixed Beam Under Gravitational Load | Validation Case | SimScale ?

Best regards,
Fillia

hello Fillia,
no, the example does not show a hinged support but a clamped support of a beam.
Do you (or a collegue) please have another proposal? A hinged support is rather common, so I think there should be a way to set it up

Johannes_ACKVA
www.code-aster.de

Hi Johannes,
currently we don’t yet support assignment of BCs on edges, but it is actually almost done and will be on production soon.
Until then you have two options using a face assignment:

  • use a remote displacement (either deformable or undeformable) and assing to the side faces with a correct axis (same as the edge you would assign the hinge support)
  • use the new cylindrical hinge constraint - here you need to use a manual axis definition as the automatic one is expects a cylindrical face. This one also allows large rotations.

Let me know if any of these work for you. You can also share the project here and I’ll set it up on your example.

Regarding the missing edges in the result mesh - we actually don’t create the edge elements as we don’t need them. once we have the edge assignment for BCs, we will also automatically have the edge elements at least on the edges where you have a BC assigned.

Best,
Richard

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