FEM Mesh/ro: Difference between revisions
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== Create a finite element mesh == |
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There are different possibilities to set up a mesh in the [[FEM Workbench]]: |
There are different possibilities to set up a mesh in the [[FEM_Workbench|FEM Workbench]]: |
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* The [[ |
* The [[FEM_MeshGmshFromShape|Gmsh tool]] from the graphical user interface. |
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* The [[ |
* The [[FEM_MeshNetgenFromShape|Netgen tool]] from the graphical user interface. |
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* Importing a mesh from another program. In particular, Gmsh and Netgen can be used by themselves outside of FreeCAD to mesh solid bodies like Step files. |
* Importing a mesh from another program. In particular, Gmsh and Netgen can be used by themselves outside of FreeCAD to mesh solid bodies like Step files. |
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* Manually creating the mesh through [[Python]] scripting. |
* Manually creating the mesh through [[Python|Python]] scripting. |
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[[Image:FEM_Workbench_workflow.svg|600px]] |
[[Image:FEM_Workbench_workflow.svg|600px]] |
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{{Caption|The FEM Workbench calls the external tool Gmsh to obtain a mesh from a solid body created with any workbench in FreeCAD; it can also import a mesh created externally}} |
{{Caption|The FEM Workbench calls the external tool Gmsh to obtain a mesh from a solid body created with any workbench in FreeCAD; it can also import a mesh created externally}} |
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[[Image:FEM_Mesh.png|600px]] |
[[Image:FEM_Mesh.png|600px]] |
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{{Caption|(1) Solid body created with PartDesign; (2) mesh produced by the Gmsh tool inside the FEM Workbench (all triangles); and (3) mesh produced externally by Gmsh, exported to Abaqus format {{FileName|.inp}}, and then imported into FreeCAD (all quadrangles)}} |
{{Caption|(1) Solid body created with PartDesign; (2) mesh produced by the Gmsh tool inside the FEM Workbench (all triangles); and (3) mesh produced externally by Gmsh, exported to Abaqus format {{FileName|.inp}}, and then imported into FreeCAD (all quadrangles)}} |
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The [[ |
The [[FEM_MeshGmshFromShape|Gmsh]] and [[FEM_MeshNetgenFromShape|Netgen tools]] are convenience tools to quickly mesh a body, and thus don't expose the full capabilities of these programs; they normally create triangular meshes, which may not be ideal for some types of analysis. If you'd like to have more control of the created mesh (use only quadrilaterals, precise element number and size, variable resolution of the mesh, etc.), you should use these programs externally, produce a mesh file in a supported format ({{FileName|.inp}}, {{FileName|.unv}}, {{FileName|.vtk}}, {{FileName|.z88}}), and import this file into FreeCAD. |
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Previously, Netgen was included with FreeCAD and could be used immediately. Now, both Netgen and Gmsh should be installed before they can be used by the [[FEM Workbench]]. Refer to [[ |
Previously, Netgen was included with FreeCAD and could be used immediately. Now, both Netgen and Gmsh should be installed before they can be used by the [[FEM Workbench]]. Refer to [[FEM_Install|FEM Install]] for instructions. |
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== Meshing software == |
== Meshing software == |
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Meshing software operates on solid bodies that can be in different formats, like Step and Brep. These programs can be used independently of FreeCAD, and typically have many options to control the meshing algorithms, element size, and boundary conditions. |
Meshing software operates on solid bodies that can be in different formats, like Step and Brep. These programs can be used independently of FreeCAD, and typically have many options to control the meshing algorithms, element size, and boundary conditions. |
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The [[FEM Workbench]] has developed simple communication interfaces to use Gmsh and Netgen directly inside FreeCAD. Other programs don't have an interface, but this could change in the future if there is interest from the community, and if those applications are easy to integrate. The meshing software can be compiled and distributed together with FreeCAD only if its license is compatible with the LGPL2 license; otherwise, the program has to be used as an external binary, like Gmsh (GPL2) is used. |
The [[FEM_Workbench|FEM Workbench]] has developed simple communication interfaces to use Gmsh and Netgen directly inside FreeCAD. Other programs don't have an interface, but this could change in the future if there is interest from the community, and if those applications are easy to integrate. The meshing software can be compiled and distributed together with FreeCAD only if its license is compatible with the LGPL2 license; otherwise, the program has to be used as an external binary, like Gmsh (GPL2) is used. |
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=== Interface implemented in FreeCAD === |
=== Interface implemented in FreeCAD === |
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* SnappyHexMesh, [https://openfoamwiki.net/index.php/SnappyHexMesh main website] |
* SnappyHexMesh, [https://openfoamwiki.net/index.php/SnappyHexMesh main website] |
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* Tetgen, [http://wias-berlin.de/software/tetgen/ main website] |
* Tetgen, [http://wias-berlin.de/software/tetgen/ main website] |
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== Mesh elements in FreeCAD == |
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| pyra 13 || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_OK.svg|20px]] || [[File:Edit_OK.svg|20px]] || [[File:Edit_OK.svg|20px]] || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_Cancel.svg|20px]] |
| pyra 13 || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_OK.svg|20px]] || [[File:Edit_OK.svg|20px]] || [[File:Edit_OK.svg|20px]] || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_Cancel.svg|20px]] || [[File:Edit_Cancel.svg|20px]] |
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* "ni" înseamnă că tipul elementului nu este implementat în FreeCAD, dar formatul îl va suporta. |
* "ni" înseamnă că tipul elementului nu este implementat în FreeCAD, dar formatul îl va suporta. |
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=== Create a FEM mesh completely in Python === |
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The Python API allows the user to define a finite element mesh by directly adding individual nodes, and defining edges, faces, and volumes. |
The Python API allows the user to define a finite element mesh by directly adding individual nodes, and defining edges, faces, and volumes. |
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obj = FreeCAD.ActiveDocument.ActiveObject |
obj = FreeCAD.ActiveDocument.ActiveObject |
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}} |
}} |
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Dacă doriți să aveți o numerotare predefinită a elementelor și nodurilor: |
Dacă doriți să aveți o numerotare predefinită a elementelor și nodurilor: |
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To create an actual document object, instead of {{incode|Fem.show()}} you can also use the document {{incode|addObject()}} method; then attach the created mesh to this object's {{incode|FemMesh}} attribute. |
To create an actual document object, instead of {{incode|Fem.show()}} you can also use the document {{incode|addObject()}} method; then attach the created mesh to this object's {{incode|FemMesh}} attribute. |
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{{Code|code= |
{{Code|code= |
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a = Fem.FemMesh() |
a = Fem.FemMesh() |
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obj.ViewObject.HighlightedNodes = [1, 2, 3] |
obj.ViewObject.HighlightedNodes = [1, 2, 3] |
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}} |
}} |
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Culori și deplasări postprocesare: |
Culori și deplasări postprocesare: |
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Set volume 1 to red |
Set volume 1 to red |
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{{Code|code= |
{{Code|code= |
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obj.ViewObject.ElementColor = {1:(1,0,0)} |
obj.ViewObject.ElementColor = {1:(1,0,0)} |
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}} |
}} |
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Set nodes 1, 2 and 3 to a certain color; the faces between the nodes acquire an interpolated color |
Set nodes 1, 2 and 3 to a certain color; the faces between the nodes acquire an interpolated color. |
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{{Code|code= |
{{Code|code= |
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obj.ViewObject.NodeColor = {1:(1,0,0), 2:(0,1,0), 3:(0,0,1)} |
obj.ViewObject.NodeColor = {1:(1,0,0), 2:(0,1,0), 3:(0,0,1)} |
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}} |
}} |
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Displace the nodes 1 and 2 by the magnitude and direction defined by a vector |
Displace the nodes 1 and 2 by the magnitude and direction defined by a vector. |
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{{Code|code= |
{{Code|code= |
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obj.ViewObject.NodeDisplacement = {1:FreeCAD.Vector(0,1,0), 2:FreeCAD.Vector(1,0,0)} |
obj.ViewObject.NodeDisplacement = {1:FreeCAD.Vector(0,1,0), 2:FreeCAD.Vector(1,0,0)} |
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}} |
}} |
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Double the factor of the displacement shown ({{Emphasis|Note to editors: removed in newer versions?}}) |
Double the factor of the displacement shown. ({{Emphasis|Note to editors: removed in newer versions?}}) |
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{{Code|code= |
{{Code|code= |
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obj.ViewObject.animate(2.0) |
obj.ViewObject.animate(2.0) |
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Add a face with the element number. |
Add a face with the element number. |
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{{Code|code= |
{{Code|code= |
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elemtria3 = Fem.FemMesh() |
elemtria3 = Fem.FemMesh() |
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Add a face with the element number. |
Add a face with the element number. |
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{{Code|code= |
{{Code|code= |
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elemtria6 = Fem.FemMesh() |
elemtria6 = Fem.FemMesh() |
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Add a face with the element number. |
Add a face with the element number. |
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{{Code|code= |
{{Code|code= |
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elemquad4 = Fem.FemMesh() |
elemquad4 = Fem.FemMesh() |
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}} |
}} |
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Add a face with the element number. |
Add a face with the element number. |
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{{Code|code= |
{{Code|code= |
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elemquad8 = Fem.FemMesh() |
elemquad8 = Fem.FemMesh() |
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Add a volume with the element number. |
Add a volume with the element number. |
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{{Code|code= |
{{Code|code= |
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elemtetra4 = Fem.FemMesh() |
elemtetra4 = Fem.FemMesh() |
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}} |
}} |
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Add a volume with the element number. |
Add a volume with the element number. |
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{{Code|code= |
{{Code|code= |
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elemtetra10 = Fem.FemMesh() |
elemtetra10 = Fem.FemMesh() |
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}} |
}} |
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Add a volume with the element number. |
Add a volume with the element number. |
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{{Code|code= |
{{Code|code= |
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elemhexa8 = Fem.FemMesh() |
elemhexa8 = Fem.FemMesh() |
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Add a volume with the element number. |
Add a volume with the element number. |
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{{Code|code= |
{{Code|code= |
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elemhexa20 = Fem.FemMesh() |
elemhexa20 = Fem.FemMesh() |
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Add a volume with the element number. |
Add a volume with the element number. |
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{{Code|code= |
{{Code|code= |
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elempenta6 = Fem.FemMesh() |
elempenta6 = Fem.FemMesh() |
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Add a volume with the element number. |
Add a volume with the element number. |
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{{Code|code= |
{{Code|code= |
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elempenta15 = Fem.FemMesh() |
elempenta15 = Fem.FemMesh() |
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Add a volume with the element number. |
Add a volume with the element number. |
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{{Code|code= |
{{Code|code= |
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elempyra5 = Fem.FemMesh() |
elempyra5 = Fem.FemMesh() |
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Add a volume with the element number. |
Add a volume with the element number. |
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{{Code|code= |
{{Code|code= |
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elempyra13 = Fem.FemMesh() |
elempyra13 = Fem.FemMesh() |
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== Scripting examples for groups == |
== Scripting examples for groups == |
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⚫ | |||
Revision as of 10:06, 31 December 2021
Create a finite element mesh
Creează o rețea MEF
Există modalități diferite de a crea o plasă de discretizare MEF în FreeCAD:
- Netgen FEM instrument Mesh FreeCAD MeshNetgenFromShape utilizând GUI sau Python
- FreeCAD FEM instrument de plasă GMSH MeshGmshFromShape utilizând GUI sau Python
- Python înseamnă a face direct FEM Mesh de mână
- Importați o plasă FEM
There are different possibilities to set up a mesh in the FEM Workbench:
- The Gmsh tool from the graphical user interface.
- The Netgen tool from the graphical user interface.
- Importing a mesh from another program. In particular, Gmsh and Netgen can be used by themselves outside of FreeCAD to mesh solid bodies like Step files.
- Manually creating the mesh through Python scripting.
Obiectele create în PartDesign și Part sunt suportate, precum și copii simple ale acestor organisme. Două ochiuri sunt disponibile pentru utilizator: Netgen și GMSH. Netgen este inclus în FreeCAD. Pentru GMSH, trebuie instalat un binar extern. Consultați FEM Install
The FEM Workbench calls the external tool Gmsh to obtain a mesh from a solid body created with any workbench in FreeCAD; it can also import a mesh created externally
(1) Solid body created with PartDesign; (2) mesh produced by the Gmsh tool inside the FEM Workbench (all triangles); and (3) mesh produced externally by Gmsh, exported to Abaqus format .inp, and then imported into FreeCAD (all quadrangles)
The Gmsh and Netgen tools are convenience tools to quickly mesh a body, and thus don't expose the full capabilities of these programs; they normally create triangular meshes, which may not be ideal for some types of analysis. If you'd like to have more control of the created mesh (use only quadrilaterals, precise element number and size, variable resolution of the mesh, etc.), you should use these programs externally, produce a mesh file in a supported format (.inp, .unv, .vtk, .z88), and import this file into FreeCAD.
Previously, Netgen was included with FreeCAD and could be used immediately. Now, both Netgen and Gmsh should be installed before they can be used by the FEM Workbench. Refer to FEM Install for instructions.
Meshing software
Meshing software operates on solid bodies that can be in different formats, like Step and Brep. These programs can be used independently of FreeCAD, and typically have many options to control the meshing algorithms, element size, and boundary conditions.
The FEM Workbench has developed simple communication interfaces to use Gmsh and Netgen directly inside FreeCAD. Other programs don't have an interface, but this could change in the future if there is interest from the community, and if those applications are easy to integrate. The meshing software can be compiled and distributed together with FreeCAD only if its license is compatible with the LGPL2 license; otherwise, the program has to be used as an external binary, like Gmsh (GPL2) is used.
Interface implemented in FreeCAD
- Gmsh: main website, code repository
- Netgen: main website, code repository
No interface in FreeCAD
- ENigMA, forum thread, code repository
- libMesh, main website, code repository, forum thread; it's a very active project, and it's C++ only
- PythonOCC, main website
- SnappyHexMesh, main website
- Tetgen, main website
Mesh elements in FreeCAD
Elemente de plasă MEF în FreeCAD
FreeCAD acceptă diferite tipuri de elemente. Există o legătură externă de blog care explică diferențele și momentul de utilizare a tipului de element: https://www.comsol.com/blogs/meshing-your-geometry-various-element-types/
- "ni" înseamnă că tipul elementului nu este implementat în FreeCAD, dar formatul îl va suporta.
- "-" înseamnă că specificația formatului nu suportă acest tip de element, deci FreeCAD nu o poate suporta.
- "?" nu se știe dacă formatul acceptă acest tip de element.
Tipuri de Elemente MEF
General
Mai multe informații despre tipurile de elemente FEM și structura lor de date în cadrul FreeCAD pot fi găsite pe FEM Elements Types.
More information on the elements, and their data structure inside FreeCAD can be found in FEM Element Types.
Segment element
Triangle element
Quadrangle element
Tetrahedron element
Hexahedron element
Pentahedron element (prism)
Pyramid element
Scripting
Create a FEM Mesh totally py python
Creating a mesh with one Tet-10 Elements
Create a FEM mesh completely in Python
See also: FreeCAD Scripting Basics.
The Python API allows the user to define a finite element mesh by directly adding individual nodes, and defining edges, faces, and volumes.
The mesh itself is of type Fem::FemMesh
, which needs to be attached to a proper document object of type Fem::FemMeshObject
.
App.ActiveDocument.Mesh_object.TypeId = Fem::FemMeshObject
.
.
.FemMesh.TypeId = Fem::FemMesh
Creating a mesh with one Tet-10 element
Create an empty FemMesh, populate it with nodes, create the volume, and finally call Fem.show()
to create the document object with the corresponding mesh.
import FreeCAD, Fem
m = Fem.FemMesh()
m.addNode(0, 1, 0)
m.addNode(0, 0, 1)
m.addNode(1, 0, 0)
m.addNode(0, 0, 0)
m.addNode(0, 0.5, 0.5)
m.addNode(0.5, 0.03, 0.5)
m.addNode(0.5, 0.5, 0.03)
m.addNode(0, 0.5, 0)
m.addNode(0.03, 0, 0.5)
m.addNode(0.5, 0, 0)
m.addVolume([1,2,3,4,5,6,7,8,9,10])
Fem.show(m)
obj = FreeCAD.ActiveDocument.ActiveObject
Dacă doriți să aveți o numerotare predefinită a elementelor și nodurilor:
To create an actual document object, instead of Fem.show()
you can also use the document addObject()
method; then attach the created mesh to this object's FemMesh
attribute.
a = Fem.FemMesh()
a.addNode(0, 1, 0, 1)
a.addNode(0, 0, 1, 2)
a.addNode(1, 0, 0, 3)
a.addNode(0, 0, 0, 4)
a.addNode(0, 0.5, 0.5, 5)
a.addNode(0.5, 0.03, 0.5, 6)
a.addNode(0.5, 0.5, 0.03, 7)
a.addNode(0, 0.5, 0, 8)
a.addNode(0.03, 0, 0.5, 9)
a.addNode(0.5, 0, 0, 10)
a.addVolume([1,2,3,4,5,6,7,8,9,10], 1)
obj_2 = FreeCAD.ActiveDocument.addObject("Fem::FemMeshObject")
obj_2.Placement.Base = FreeCAD.Vector(2, 0, 0)
obj_2.FemMesh = a
Manipulare vizuală
Evidențiați unele noduri din vizualizare:
Once a FemMesh object has been created with Fem.show()
, some of its visual properties can be changed by modifying the different attributes of its ViewObject
. This can be useful to postprocess the mesh after a finite element solution has been obtained.
Highlight some nodes in the mesh
Fem.show(m)
obj = FreeCAD.ActiveDocument.ActiveObject
obj.ViewObject.HighlightedNodes = [1, 2, 3]
Culori și deplasări postprocesare: Evidențiați unele noduri din vizualizare:
Set volume 1 to red
obj.ViewObject.ElementColor = {1:(1,0,0)}
Set nodes 1, 2 and 3 to a certain color; the faces between the nodes acquire an interpolated color.
obj.ViewObject.NodeColor = {1:(1,0,0), 2:(0,1,0), 3:(0,0,1)}
Displace the nodes 1 and 2 by the magnitude and direction defined by a vector.
obj.ViewObject.NodeDisplacement = {1:FreeCAD.Vector(0,1,0), 2:FreeCAD.Vector(1,0,0)}
Double the factor of the displacement shown. (Note to editors: removed in newer versions?)
obj.ViewObject.animate(2.0)
Script un element al fiecărui tip de Element acceptat
Beam, 2 node line, seg2 (linear)
import Fem
seg2 = Fem.FemMesh()
seg2.addNode( 0, 0, 0, 1)
seg2.addNode(10, 0, 0, 2)
seg2.addEdge(1, 2)
print(seg2)
obj = FreeCAD.ActiveDocument.addObject("Fem::FemMeshObject", "seg2")
obj.FemMesh = seg2
obj.Placement.Base = FreeCAD.Vector(0, 110, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Beam, 3 node line, seg3 (quadratic)
import Fem
seg3 = Fem.FemMesh()
seg3.addNode( 0, 0, 0, 1)
seg3.addNode(10, 0, 0, 2)
seg3.addNode( 5, 0, 0, 3)
seg3.addEdge([1, 2, 3])
print(seg3)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "seg3")
obj.FemMesh = seg3
obj.Placement.Base = FreeCAD.Vector(30, 110, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Shell, 3 node triangle, tria3 (linear)
import Fem
tria3 = Fem.FemMesh()
tria3.addNode( 0, 0, 0, 1)
tria3.addNode( 6, 12, 0, 2)
tria3.addNode(12, 0, 0, 3)
tria3.addFace([1, 2, 3])
print(tria3)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "tria3")
obj.FemMesh = tria3
obj.Placement.Base = FreeCAD.Vector(0, 80, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
Add a face with the element number.
elemtria3 = Fem.FemMesh()
nodes = tria3.Nodes
for n in nodes:
elemtria3.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elemtria3.addFace([1, 2, 3], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elemtria3")
obj.FemMesh = elemtria3
obj.Placement.Base = FreeCAD.Vector(200, 80, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
print(elemtria3.Faces)
Shell, 6 node triangle, tria6 (quadratic)
import Fem
tria6 = Fem.FemMesh()
tria6.addNode( 0, 0, 0, 1)
tria6.addNode( 6, 12, 0, 2)
tria6.addNode(12, 0, 0, 3)
tria6.addNode( 3, 6, 0, 4)
tria6.addNode( 9, 6, 0, 5)
tria6.addNode( 6, 0, 0, 6)
tria6.addFace([1, 2, 3, 4, 5, 6])
print(tria6)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "tria6")
obj.FemMesh = tria6
obj.Placement.Base = FreeCAD.Vector(30, 80, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
Add a face with the element number.
elemtria6 = Fem.FemMesh()
nodes = tria6.Nodes
for n in nodes:
elemtria6.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elemtria6.addFace([1, 2, 3, 4, 5, 6], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elemtria6")
obj.FemMesh = elemtria6
obj.Placement.Base = FreeCAD.Vector(230, 80, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
print(elemtria6.Faces)
Shell, 4 node quadrangle, quad4 (linear)
import Fem
quad4 = Fem.FemMesh()
quad4.addNode( 0, 10, 0, 1)
quad4.addNode(10, 10, 0, 2)
quad4.addNode(10, 0, 0, 3)
quad4.addNode( 0, 0, 0, 4)
quad4.addFace([1, 2, 3, 4])
print(quad4)
obj = FreeCAD.ActiveDocument.addObject("Fem::FemMeshObject", "quad4")
obj.FemMesh = quad4
obj.Placement.Base = FreeCAD.Vector(60, 80, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
Add a face with the element number.
elemquad4 = Fem.FemMesh()
nodes = quad4.Nodes
for n in nodes:
elemquad4.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elemquad4.addFace([1, 2, 3, 4], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elemquad4")
obj.FemMesh = elemquad4
obj.Placement.Base = FreeCAD.Vector(260, 80, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
print(elemquad4.Faces)
Shell, 8 node quadrangle, quad8 (quadratic)
import Fem
quad8 = Fem.FemMesh()
quad8.addNode( 0, 10, 0, 1)
quad8.addNode(10, 10, 0, 2)
quad8.addNode(10, 0, 0, 3)
quad8.addNode( 0, 0, 0, 4)
quad8.addNode( 5, 10, 0, 5)
quad8.addNode(10, 5, 0, 6)
quad8.addNode( 5, 0, 0, 7)
quad8.addNode( 0, 5, 0, 8)
quad8.addFace([1, 2, 3, 4, 5, 6, 7, 8])
print(quad8)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "quad8")
obj.FemMesh = quad8
obj.Placement.Base = FreeCAD.Vector(90, 80, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
Add a face with the element number.
elemquad8 = Fem.FemMesh()
nodes = quad8.Nodes
for n in nodes:
elemquad8.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elemquad8.addFace([1, 2, 3, 4, 5, 6, 7, 8], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elemquad8")
obj.FemMesh = elemquad8
obj.Placement.Base = FreeCAD.Vector(290, 80, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
print(elemquad8.Faces)
Volume, 4 node tetrahedron, tetra4 (linear)
import Fem
tetra4 = Fem.FemMesh()
tetra4.addNode( 6, 12, 18, 1)
tetra4.addNode( 0, 0, 18, 2)
tetra4.addNode(12, 0, 18, 3)
tetra4.addNode( 6, 6, 0, 4)
tetra4.addVolume([1, 2, 3, 4])
print(tetra4)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "tetra4")
obj.FemMesh = tetra4
obj.Placement.Base = FreeCAD.Vector(0, 50, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Add a volume with the element number.
elemtetra4 = Fem.FemMesh()
nodes = tetra4.Nodes
for n in nodes:
elemtetra4.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elemtetra4.addVolume([1, 2, 3, 4], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elemtetra4")
obj.FemMesh = elemtetra4
obj.Placement.Base = FreeCAD.Vector(200, 50, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
print(elemtetra4.Volumes)
Volume, 10 node tetrahedron, tetra10 (quadratic)
import Fem
tetra10 = Fem.FemMesh()
tetra10.addNode( 6, 12, 18, 1)
tetra10.addNode( 0, 0, 18, 2)
tetra10.addNode(12, 0, 18, 3)
tetra10.addNode( 6, 6, 0, 4)
tetra10.addNode( 3, 6, 18, 5)
tetra10.addNode( 6, 0, 18, 6)
tetra10.addNode( 9, 6, 18, 7)
tetra10.addNode( 6, 9, 9, 8)
tetra10.addNode( 3, 3, 9, 9)
tetra10.addNode( 9, 3, 9,10)
tetra10.addVolume([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
print(tetra10)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "tetra10")
obj.FemMesh = tetra10
obj.Placement.Base = FreeCAD.Vector(30, 50, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Add a volume with the element number.
elemtetra10 = Fem.FemMesh()
nodes = tetra10.Nodes
for n in nodes:
elemtetra10.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elemtetra10.addVolume([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elemtetra10")
obj.FemMesh = elemtetra10
obj.Placement.Base = FreeCAD.Vector(230, 50, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
print(elemtetra10.Volumes)
Volume, 8 node hexahedron, hexa8 (linear)
import Fem
hexa8 = Fem.FemMesh()
hexa8.addNode( 0, 10, 10, 1)
hexa8.addNode( 0, 0, 10, 2)
hexa8.addNode(10, 0, 10, 3)
hexa8.addNode(10, 10, 10, 4)
hexa8.addNode( 0, 10, 0, 5)
hexa8.addNode( 0, 0, 0, 6)
hexa8.addNode(10, 0, 0, 7)
hexa8.addNode(10, 10, 0, 8)
hexa8.addVolume([1, 2, 3, 4, 5, 6, 7, 8])
print(hexa8)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "hexa8")
obj.FemMesh = hexa8
obj.Placement.Base = FreeCAD.Vector(60, 50, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Add a volume with the element number.
elemhexa8 = Fem.FemMesh()
nodes = hexa8.Nodes
for n in nodes:
elemhexa8.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elemhexa8.addVolume([1, 2, 3, 4, 5, 6, 7, 8], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elemhexa8")
obj.FemMesh = elemhexa8
obj.Placement.Base = FreeCAD.Vector(260, 50, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
print(elemhexa8.Volumes)
Volume, 20 node hexahedron, hexa20 (quadratic)
import Fem
hexa20 = Fem.FemMesh()
hexa20.addNode( 0, 10, 10, 1)
hexa20.addNode( 0, 0, 10, 2)
hexa20.addNode(10, 0, 10, 3)
hexa20.addNode(10, 10, 10, 4)
hexa20.addNode( 0, 10, 0, 5)
hexa20.addNode( 0, 0, 0, 6)
hexa20.addNode(10, 0, 0, 7)
hexa20.addNode(10, 10, 0, 8)
hexa20.addNode( 0, 5, 10, 9)
hexa20.addNode( 5, 0, 10, 10)
hexa20.addNode(10, 5, 10, 11)
hexa20.addNode( 5, 10, 10, 12)
hexa20.addNode( 0, 5, 0, 13)
hexa20.addNode( 5, 0, 0, 14)
hexa20.addNode(10, 5, 0, 15)
hexa20.addNode( 5, 10, 0, 16)
hexa20.addNode( 0, 10, 5, 17)
hexa20.addNode( 0, 0, 5, 18)
hexa20.addNode(10, 0, 5, 19)
hexa20.addNode(10, 10, 5, 20)
hexa20.addVolume([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20])
print(hexa20)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "hexa20")
obj.FemMesh = hexa20
obj.Placement.Base = FreeCAD.Vector(90, 50, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Add a volume with the element number.
elemhexa20 = Fem.FemMesh()
nodes = hexa20.Nodes
for n in nodes:
elemhexa20.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elemhexa20.addVolume([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elemhexa20")
obj.FemMesh = elemhexa20
obj.Placement.Base = FreeCAD.Vector(290, 50, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
print(elemhexa20.Volumes)
Volume, 6 node pentahedron, penta6 (linear)
import Fem
penta6 = Fem.FemMesh()
penta6.addNode(10, 10, 10, 1)
penta6.addNode( 0, 0, 10, 2)
penta6.addNode(20, 0, 10, 3)
penta6.addNode(10, 10, 0, 4)
penta6.addNode( 0, 0, 0, 5)
penta6.addNode(20, 0, 0, 6)
penta6.addVolume([1, 2, 3, 4, 5, 6])
print(penta6)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "penta6")
obj.FemMesh = penta6
obj.Placement.Base = FreeCAD.Vector(0, 0, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Add a volume with the element number.
elempenta6 = Fem.FemMesh()
nodes = penta6.Nodes
for n in nodes:
elempenta6.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elempenta6.addVolume([ 1, 2, 3, 4, 5, 6], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elempenta6")
obj.FemMesh = elempenta6
obj.Placement.Base = FreeCAD.Vector(200, 0, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
print(elempenta6.Volumes)
Volume, 15 node pentahedron, penta15 (quadratic)
import Fem
penta15 = Fem.FemMesh()
penta15.addNode(10, 10, 10, 1)
penta15.addNode( 0, 0, 10, 2)
penta15.addNode(20, 0, 10, 3)
penta15.addNode(10, 10, 0, 4)
penta15.addNode( 0, 0, 0, 5)
penta15.addNode(20, 0, 0, 6)
penta15.addNode( 5, 5, 10, 7)
penta15.addNode(10, 0, 10, 8)
penta15.addNode(15, 5, 10, 9)
penta15.addNode( 5, 5, 0, 10)
penta15.addNode(10, 0, 0, 11)
penta15.addNode(15, 5, 0, 12)
penta15.addNode(10, 10, 5, 13)
penta15.addNode( 0, 0, 5, 14)
penta15.addNode(20, 0, 5, 15)
penta15.addVolume([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15])
print(penta15)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "penta15")
obj.FemMesh = penta15
obj.Placement.Base = FreeCAD.Vector(40, 0, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Add a volume with the element number.
elempenta15 = Fem.FemMesh()
nodes = penta15.Nodes
for n in nodes:
elempenta15.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elempenta15.addVolume([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elempenta15")
obj.FemMesh = elempenta15
obj.Placement.Base = FreeCAD.Vector(240, 0, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
print(elempenta15.Volumes)
Volume, 5 node pyramid, pyra5 (linear)
import Fem
pyra5 = Fem.FemMesh()
pyra5.addNode( 0, 20, 0, 1)
pyra5.addNode(20, 20, 0, 2)
pyra5.addNode(20, 0, 0, 3)
pyra5.addNode( 0, 0, 0, 4)
pyra5.addNode(10, 10, 10, 5)
pyra5.addVolume([1, 2, 3, 4, 5])
print(pyra5)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "pyra5")
obj.FemMesh = pyra5
obj.Placement.Base = FreeCAD.Vector(80, 0, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Add a volume with the element number.
elempyra5 = Fem.FemMesh()
nodes = pyra5.Nodes
for n in nodes:
elempyra5.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elempyra5.addVolume([1, 2, 3, 4, 5], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elempyra5")
obj.FemMesh = elempyra5
obj.Placement.Base = FreeCAD.Vector(280, 0, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
print(elempyra5.Volumes)
Volume, 13 node pyramid, pyra13 (quadratic)
import Fem
pyra13 = Fem.FemMesh()
pyra13.addNode( 0, 20, 0, 1)
pyra13.addNode(20, 20, 0, 2)
pyra13.addNode(20, 0, 0, 3)
pyra13.addNode( 0, 0, 0, 4)
pyra13.addNode(10, 10, 10, 5)
pyra13.addNode(10, 20, 0, 6)
pyra13.addNode(20, 10, 0, 7)
pyra13.addNode(10, 0, 0, 8)
pyra13.addNode( 0, 10, 0, 9)
pyra13.addNode( 5, 15, 5, 10)
pyra13.addNode(15, 15, 5, 11)
pyra13.addNode(15, 5, 5, 12)
pyra13.addNode( 5, 5, 5, 13)
pyra13.addVolume([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13])
print(pyra13)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "pyra13")
obj.FemMesh = pyra13
obj.Placement.Base = FreeCAD.Vector(120, 0, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
Add a volume with the element number.
elempyra13 = Fem.FemMesh()
nodes = pyra13.Nodes
for n in nodes:
elempyra13.addNode(nodes[n].x, nodes[n].y, nodes[n].z, n)
elempyra13.addVolume([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject", "elempyra13")
obj.FemMesh = elempyra13
obj.Placement.Base = FreeCAD.Vector(320, 0, 0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
print(elempyra13.Volumes)
Scripting examples for groups
See for example https://forum.freecadweb.org/viewtopic.php?f=18&t=37304&start=20#p318823
- Materials: Solid, Fluid, Nonlinear mechanical, Reinforced (concrete); Material editor
- Element geometry: Beam (1D), Beam rotation (1D), Shell (2D), Fluid flow (1D)
Constraints
- Electromagnetic: Electrostatic potential, Current density, Magnetization
- Geometrical: Plane rotation, Section print, Transform
- Mechanical: Fixed, Displacement, Contact, Tie, Spring, Force, Pressure, Centrif, Self weight
- Thermal: Initial temperature, Heat flux, Temperature, Body heat source
- Overwrite Constants: Constant vacuum permittivity
- Solve: CalculiX Standard, Elmer, Mystran, Z88; Equations: Deformation, Elasticity, Electrostatic, Electricforce, Magnetodynamic, Magnetodynamic 2D, Flow, Flux, Heat; Solver: Solver control, Solver run
- Results: Purge, Show; Postprocessing: Apply changes, Pipeline from result, Warp filter, Scalar clip filter, Function cut filter, Region clip filter, Contours filter, Line clip filter, Stress linearization plot, Data at point clip filter, Filter function plane, Filter function sphere, Filter function cylinder, Filter function box
- Additional: Preferences; FEM Install, FEM Mesh, FEM Solver, FEM CalculiX, FEM Concrete; FEM Element Types
- Getting started
- Installation: Download, Windows, Linux, Mac, Additional components, Docker, AppImage, Ubuntu Snap
- Basics: About FreeCAD, Interface, Mouse navigation, Selection methods, Object name, Preferences, Workbenches, Document structure, Properties, Help FreeCAD, Donate
- Help: Tutorials, Video tutorials
- Workbenches: Std Base, Arch, Assembly, CAM, Draft, FEM, Inspection, Mesh, OpenSCAD, Part, PartDesign, Points, Reverse Engineering, Robot, Sketcher, Spreadsheet, Start, Surface, TechDraw, Test Framework, Web
- Hubs: User hub, Power users hub, Developer hub