FEM ConstraintContact

Constraint plane rotation

Constraint transform

FEM

FEM ConstraintContact
Menu location
Model → Mechanical Constraints → Constraint contact
Workbenches
FEM
Default shortcut
None
Introduced in version
-
See also
FEM tutorial

Description

Creates a FEM constraint for contact between 2 surfaces.

How to use

1. Click on or choose Model → Mechanical Constraints → Constraint contact from the top menu.
2. Select the master face.
3. Select the slave face.
4. Enter a contact stiffness.
5. Enter a friction coefficient.

Limitations

1. The contact constraint can only be applied to two faces.

Notes

CalculiX

• The contact stiffness should be 10 times the young's modulus of the material for hard contact. The higher the value for contact stiffness, the harder the contact between surfaces.
• The slave face is the face which penetrates into the master face, and therefore experiences more deformation.
• The *CONTACT PAIR card is used for modeling contact in CalculiX. The constraint uses Face-to-Face penalty contact and the contact formulation is explained in detail at http://web.mit.edu/calculix_v2.7/CalculiX/ccx_2.7/doc/ccx/node112.html
• Overview for different contact types: https://forum.freecadweb.org/viewtopic.php?f=18&t=15699&start=90#p188736
• Further interesting informations:
  • https://forum.freecadweb.org/viewtopic.php?f=18&t=23102#p180709 and following posts !!!
  • https://forum.freecadweb.org/viewtopic.php?f=18&t=20276
  • https://forum.freecadweb.org/viewtopic.php?f=18&t=21331
  • https://forum.freecadweb.org/viewtopic.php?f=18&t=15699 (initial contact topic)

• A very detailed CalculiX contact example:
  • http://dip28p.web.fc2.com/calculix/netgen2calculix/index.html

Constraint plane rotation

Constraint transform

FEM

FEM

• FEM Analysis

• Materials: Solid, Fluid, Nonlinear mechanical, Reinforced (concrete); Material editor

• Element geometry: Beam (1D), Beam rotation (1D), Shell (2D), Fluid flow (1D)

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Constraints

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• Overwrite Constants: Constant vacuum permittivity

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• Utilities: Clipping plane, Remove clipping planes, Open FEM examples; Mesh clear, Mesh display info

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• Additional: Preferences; FEM Install, FEM Mesh, FEM Solver, FEM CalculiX, FEM Concrete; FEM Element Types

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