FEM Mesh/ro

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 GPL2 or LGPL2 licenses; otherwise, the program has to be used as an external binary, like Gmsh 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

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/

Import and export of mesh elements

Element	Element	FreeCAD API	FreeCAD GUI	med	unv	inp	frd	txt	xml
Med	CalculiX	Python	FEM Mesh	SMESH	IDEAS/FreeCAD	Abaqus/CalculiX	Result Mesh	Z88	Fenics
Name	Name	create elements	view elements	import/export	import/export	import/export	import	import/export	import/export
seg 2	B31
seg 3	B32							NI
tria 3	S3
tria 6	S6
quad 4	S4
quad 8	S8
tetra 4	C3D4
tetra 10	C3D10
hexa 8	C3D8								() the format allows it, but it's not readable or writable by fenics
hexa 20	C3D20
penta 6	C3D6							?
penta 15	C3D15							?
pyra 5
pyra 13

• "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

See also: FreeCAD Scripting Basics.

The Python API allows the user to define a finite element mesh by directly adding individual nodes.

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)

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

• Electromagnetic: Electrostatic potential, Current density, Magnetization

• Fluid: Initial flow velocity, Initial pressure, Flow velocity

• 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

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• Mesh: Mesh Netgen, Mesh GMSH, Mesh boundary layer, Mesh region, Mesh group, Nodes set, Mesh to mesh

• 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

• 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

User documentation

• 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

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• 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

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• Addons: Addon Manager, External workbenches, Scripting and macros

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• Hubs: User hub, Power users hub, Developer hub