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 FreeCAD:

• 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); (3) and mesh produced externally by Gmsh (using Abaqus format .inp), and then imported into FreeCAD (mostly quadrilaterals)

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 FEM 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
pyra 5
pyra 13
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							?

• "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.

General

More information on the elements, and their data structure inside FreeCAD can be found in FEM Element Types.

Segment element

File:Segments.gif

Triangle element

File:Triangles.gif

Quadratic element

File:Quadrangles.gif

Tetrahedron element

File:Tetraedres.gif

Pyramid element

File:Pyramides.gif

Hexahedron element

File:Hexaedres.gif

Pentahedron element

File:Pentaedres.gif

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 Elements

Create an empty mesh object, populate it with nodes, add the volume, and show the 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,.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)

Dacă doriți să aveți o numerotare predefinită a elementelor și nodurilor:

m.addNode(0.0,1.0,0.0,1)
m.addVolume([1,2,3,4,5,6,7,8,9,10],1)

Manipulare vizuală

Evidențiați unele noduri din vizualizare:

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,.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)
Gui.ActiveDocument.ActiveObject.HighlightedNodes = [1,2,3]

Culori și deplasări postprocesare: Evidențiați unele noduri din vizualizare:

# set the volume 1 to red
Gui.ActiveDocument.ActiveObject.ElementColor= {1:(1,0,0)}

# set the node 1 and 2 to a certain color and interpolate the surface
Gui.ActiveDocument.ActiveObject.NodeColor= {1:(1,0,0), 2:(1,0,0)}

# set the node 1 and 2 to a certain displacement
Gui.ActiveDocument.ActiveObject.NodeDisplacement= {1:FreeCAD.Vector(1,0,0), 2:FreeCAD.Vector(1,0,0)}

# double the factor of the displacement shown
Gui.ActiveDocument.ActiveObject.animate(2.0)

Script un element al fiecărui tip de Element acceptat

import Fem
#################################################
# Beams
# 2 node line --> seg2 ##########################
seg2 = Fem.FemMesh()
seg2.addNode( 0,  0, 0, 1)
seg2.addNode(10,  0, 0, 2)
seg2.addEdge(1, 2)
seg2
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","seg2")
obj.FemMesh = seg2
obj.Placement.Base = (0,110,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"


# 3 node line --> seg3 ##########################

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])
seg3
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","seg3")
obj.FemMesh = seg3
obj.Placement.Base = (30,110,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"


#################################################
# Shells
# 3 node triangle --> tria3 #####################
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])
tria3
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","tria3")
obj.FemMesh = tria3
obj.Placement.Base = (0,80,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
# add Face with element number
elemtria3 = Fem.FemMesh()
nds = tria3.Nodes
for n in nds:
    elemtria3.addNode(nds[n].x, nds[n].y, nds[n].z, n)

elemtria3.addFace([1,  2,  3], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","elemtria3")
obj.FemMesh = elemtria3
obj.Placement.Base = (200,80,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
elemtria3.Faces


# 6 node triangle --> tria 6 ####################
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])
tria6
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","tria6")
obj.FemMesh = tria6
obj.Placement.Base = (30,80,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
# add Face with element number
elemtria6 = Fem.FemMesh()
nds = tria6.Nodes
for n in nds:
    elemtria6.addNode(nds[n].x, nds[n].y, nds[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 = (230,80,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
elemtria6.Faces


# 4 node quad --> quad4 #########################
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])
quad4
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","quad4")
obj.FemMesh = quad4
obj.Placement.Base = (60,80,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
# add Face with element number
elemquad4 = Fem.FemMesh()
nds = quad4.Nodes
for n in nds:
    elemquad4.addNode(nds[n].x, nds[n].y, nds[n].z, n)

elemquad4.addFace([1,  2,  3,  4], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","elemquad4")
obj.FemMesh = elemquad4
obj.Placement.Base = (260,80,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
elemquad4.Faces


# 8 node quad --> quad8 #########################
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])
quad8
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","quad8")
obj.FemMesh = quad8
obj.ViewObject.BackfaceCulling = False
obj.Placement.Base = (90,80,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
# add Face with element number
elemquad8 = Fem.FemMesh()
nds = quad8.Nodes
for n in nds:
    elemquad8.addNode(nds[n].x, nds[n].y, nds[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 = (290,80,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
obj.ViewObject.BackfaceCulling = False
elemquad8.Faces


#################################################
# Volumes
# 4 node tetrahedron --> tetra4 #################
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])
tetra4
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","tetra4")
obj.FemMesh = tetra4
obj.Placement.Base = (0,50,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
# add Volume with element number
elemtetra4 = Fem.FemMesh()
nds = tetra4.Nodes
for n in nds:
    elemtetra4.addNode(nds[n].x, nds[n].y, nds[n].z, n)

elemtetra4.addVolume([1,  2,  3, 4], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","elemtetra4")
obj.FemMesh = elemtetra4
obj.Placement.Base = (200,50,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
elemtetra4.Volumes


# 10 node tetrahedron --> tetra10 ###############
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])
tetra10
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","tetra10")
obj.FemMesh = tetra10
obj.Placement.Base = (30,50,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
# add Volume with element number
elemtetra10 = Fem.FemMesh()
nds = tetra10.Nodes
for n in nds:
    elemtetra10.addNode(nds[n].x, nds[n].y, nds[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 = (230,50,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
elemtetra10.Volumes


# 8 node Hexahedron --> hexa8 ###################
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])
hexa8
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","hexa8")
obj.FemMesh = hexa8
obj.Placement.Base = (60,50,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
# add Volume with element number
elemhexa8 = Fem.FemMesh()
nds = hexa8.Nodes
for n in nds:
    elemhexa8.addNode(nds[n].x, nds[n].y, nds[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 = (260,50,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
elemhexa8.Volumes


# 20 node Hexahedron --> hexa20 #################
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])
hexa20
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","hexa20")
obj.FemMesh = hexa20
obj.Placement.Base = (90,50,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
# add Volume with element number
elemhexa20 = Fem.FemMesh()
nds = hexa20.Nodes
for n in nds:
    elemhexa20.addNode(nds[n].x, nds[n].y, nds[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 = (290,50,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
elemhexa20.Volumes


# 6 node pentahedron --> penta6 #################
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])
penta6
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","penta6")
obj.FemMesh = penta6
obj.Placement.Base = (0,0,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
# add Volume with element number
elempenta6 = Fem.FemMesh()
nds = penta6.Nodes
for n in nds:
    elempenta6.addNode(nds[n].x, nds[n].y, nds[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 = (200,0,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
elempenta6.Volumes


# 15 node pentahedron --> penta15 ###############
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])
penta15
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","penta15")
obj.FemMesh = penta15
obj.Placement.Base = (40,0,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
# add Volume with element number
elempenta15 = Fem.FemMesh()
nds = penta15.Nodes
for n in nds:
    elempenta15.addNode(nds[n].x, nds[n].y, nds[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 = (240,0,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
elempenta15.Volumes


# 5 node pyramid --> pyra5 ######################
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])
pyra5
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","pyra5")
obj.FemMesh = pyra5
obj.Placement.Base = (80,0,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
# add Volume with element number
elempyra5 = Fem.FemMesh()
nds = pyra5.Nodes
for n in nds:
    elempyra5.addNode(nds[n].x, nds[n].y, nds[n].z, n)

elempyra5.addVolume([1,  2,  3, 4, 5], 88)
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","elempyra5")
obj.FemMesh = elempyra5
obj.Placement.Base = (280,0,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
elempyra5.Volumes


# 13 node pyramid --> pyra13 ####################
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)
pyra5 = Fem.FemMesh()
pyra13.addNode( 5, 5, 5,13)
pyra13.addVolume([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13])
pyra13
obj = App.ActiveDocument.addObject("Fem::FemMeshObject","pyra13")
obj.FemMesh = pyra13
obj.Placement.Base = (120,0,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
# add Volume with element number
elempyra13 = Fem.FemMesh()
nds = pyra13.Nodes
for n in nds:
    elempyra13.addNode(nds[n].x, nds[n].y, nds[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 = (320,0,0)
obj.ViewObject.DisplayMode = "Faces, Wireframe & Nodes"
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