FEM MeshGroup
|
|
| Menu location |
|---|
| Mesh → Mesh Group |
| Workbenches |
| FEM |
| Default shortcut |
| None |
| Introduced in version |
| - |
| See also |
| FEM tutorial |
Description[edit | edit source]
The FEM MeshGroup command enables the user to create groups of Vertices, Edges, Surfaces and elements. It is useful in case of using FreeCAD as a pre-processor to export an organized and labeled mesh. The mesh is then usable by external solver codes, where mesh groups can be used more readily to set boundary conditions and attribute solver related properties. It is possible to use the FreeCAD mesh group object name or the label as the group name on export of the mesh. If the label is chosen, the user has to be mindful if special characters are used. If the mesh export format does not allow special character its fallback is to use the mesh group object name.
FEM MeshGroup therefore enables FreeCAD to be used with external solvers (or viewers such as ParaView) when they are not yet implemented with their own case-writing routine within FreeCAD.
Usage[edit | edit source]
- To enable the command a
Mesh From Shape by Gmsh must be provided first.
- Select the Mesh object in the Tree View.
- There are several ways to invoke the command:
- Press the
Mesh Group button.
- Select the Mesh →
Mesh Group option from the menu.
- Press the
- Select whether the group is named or labeled
- If Name is selected, the name of the MeshGroup is used when exporting the mesh.
- If Label is selected, the specified label name will be used when exporting the mesh.
- Click the Add button and select the geometrical entity (solid, face, edge or vertex). More such objects can be added but they have to be of the same type. The mesh group will consist of underlying mesh entities. introduced in 1.1: To remove objects from the selection, press the Remove button.
- Click the OK button.
- Result: You now should see a new
FEMMeshGroupobject under theFEMMeshGMSHobject in your active analysis container.
- Result: You now should see a new
- Double-click on the
FEMMeshGMSHparent object in your Model Tree and press Apply to force a mesh recalculation / relabeling. - Close the task.
Notes[edit | edit source]
- After the mesh has been created, you can change the label property using the Property View.
- After you change a property, you must reopen the Gmsh dialog again and click the Apply button (you can leave the dialog open while changing properties).
- You can create as many different mesh groups as needed.
- By default, mesh groups can only be exported to .med, .unv, .xdmf (without DataGroups Of Nodes) and YAML/JSON formats. To be able to export them to the .inp format, one needs to enable the Export group data option in INP export preferences.
- Setting the Which mesh elements to export to Highest or FEM ensures that lower order elements not used for analysis (e.g. shells in the case of analysis with solids) won't be exported.
- To export node sets to this format, the DataGroups Of Nodes property of the Gmsh mesh object must be set to
true.
- To check if a group was properly exported, you can open the generated file in any text editor and search for the group's name.
- Materials: Solid Material, Fluid Material, Non-Linear Mechanical Material, Reinforced Material (Concrete); Material Editor
- Element Geometry: Beam Cross Section, Beam Rotation, Shell Plate Thickness, Fluid Section for 1D Flow
- Electromagnetic Boundary Conditions: Electrostatic Potential Boundary Condition, Current Density Boundary Condition, Magnetization Boundary Condition, Electric Charge Density
- Fluid Boundary Conditions: Initial Flow Velocity Condition, Initial Pressure Condition, Flow Velocity Boundary Condition
- Geometrical Analysis Features: Plane Multi-Point Constraint, Section Print Feature, Local Coordinate System
- Mechanical Boundary Conditions and Loads: Fixed Boundary Condition, Rigid Body Constraint, Displacement Boundary Condition, Contact Constraint, Tie Constraint, Spring Boundary Condition, Force Load, Pressure Load, Centrifugal Load, Gravity Load
- Thermal Boundary Conditions and Loads: Initial Temperature, Heat Flux Load, Temperature Boundary Condition, Body Heat Source
- Overwrite Constants: Constant Vacuum Permittivity
- Mesh: Mesh From Shape by Netgen, Mesh From Shape by Gmsh, Mesh Boundary Layer, Mesh Refinement, Mesh Group, Erase Elements, FEM Mesh to Mesh
- Solve: Solver CalculiX, Solver Elmer, Solver Mystran, Solver Z88; Mechanical Equations: Elasticity Equation, Deformation Equation; Electromagnetic Equations: Electrostatic Equation, Electricforce Equation, Magnetodynamic Equation, Magnetodynamic 2D Equation, Static Current Equation; Flow Equation, Flux Equation, Heat Equation, Solver Job Control, Run Solver
- Results: Purge Results, Show Result, Apply Changes to Pipeline, Post Pipeline From Result, Pipeline Branch, Warp Filter, Scalar Clip Filter, Function Cut Filter, Region Clip Filter, Contours Filter, Glyph Filter, Line Clip Filter, Stress Linearization Plot, Data at Point Clip Filter, Calculator Filter; Filter Functions: Plane, Sphere, Cylinder, Box; Data Visualizations: Create Lineplot, Create Histogram, Create Table
- Utilities: Clipping Plane on Face, Remove All Clipping Planes, FEM Examples; Clear FEM Mesh, Display Mesh Info
- Additional: Preferences; FEM Install, FEM Mesh, FEM Solver, FEM CalculiX, FEM Concrete; FEM Element Types
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