FEM Mesh CalculiX

FEM element types in CalculiX

For detailed information on FreeCAD FEM elements see FEM Mesh and FEM Element Types. For CalculiX specific questions you may try the Discourse group or the Discord channel.

Segment element

Segment element from FreeCAD to CalculiX -- node assignment

seg2 FreeCAD nodes	seg3 FreeCAD nodes
seg2 (B31) CalculiX nodes	seg3 (B32) CalculiX nodes
FreeCAD → CalculiX, Nodes
N1, N2	N1, N3, N2

Triangle element

Triangle element from FreeCAD to CalculiX -- node assignment

tria3 FreeCAD nodes	tria6 FreeCAD nodes
tria3 (S3) CalculiX nodes	tria6 (S6) CalculiX nodes
FreeCAD → CalculiX, Nodes
N1, N2, N3	N1, N2, N3, N4, N5, N6

Quadratic element

Quadratic element from FreeCAD to CalculiX -- node assignment

quad4 FreeCAD nodes	quad8 FreeCAD nodes
quad4 (S4) CalculiX nodes	quad8 (S8) CalculiX nodes
FreeCAD → CalculiX, Nodes
N1, N2, N3, N4	N1, N2, N3, N4, N5, N6, N7, N8

Tetrahedron element

The following node order is not implemented ! TODO: verify node order (do not forget getccxVolumesByFace()).

Tetrahedron element from FreeCAD to CalculiX -- node assignment

tetra4 FreeCAD nodes	tetra10 FreeCAD nodes
tetra4 (C3D4) CalculiX nodes	tetra10 (C3D10) CalculiX nodes
FreeCAD → CalculiX, Nodes
N2, N3, N4, N1	N2, N3, N4, N1, N6, N10, N9, N5, N7, N8

Hexahedron element

Hexahedron element from FreeCAD to CalculiX -- node assignment

hexa8 FreeCAD nodes	hexa20 FreeCAD nodes
hexa8 (C3D8) CalculiX nodes	hexa20 (C3D20) CalculiX nodes
FreeCAD → CalculiX, Nodes
N6, N7, N8, N5, N2, N3, N4, N1	N6, N7, N8, N5, N2, N3, N4, N1 , N14, N15, N16, N13, N10, N11, N12, N9, N18, N19, N20, N17

Pentahedron element

Pentahedron element from FreeCAD to CalculiX -- node assignment

penta6 FreeCAD nodes	penta15 FreeCAD nodes
penta6 (C3D6) CalculiX nodes	penta15 (C3D15) CalculiX nodes
FreeCAD → CalculiX, Nodes
N5, N6, N4, N2, N3, N1	N5, N6, N4, N2, N3, N1, N11, N12, N10, N8, N9, N7, N14, N15, N13

FEM

• FEM Analysis

• Materials: Solid, Fluid, Nonlinear mechanical; Material editor

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

---

Constraints

• Electrostatic: Potential

• Fluid: Initial velocity, Fluid boundary, Flow velocity

• Mechanical: Fixed, Displacement, Plane rotation, Contact, Transform, Force, Pressure, Self weight, Bearing, Gear, Pulley

• Thermal: Initial temperature, Heat flux, Temperature, Heat source

---

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

• Solve: Calculix tools, CalculiX, Elmer, Z88; Equations: Heat, Elasticity, Electrostatic, Flux, Flow; Solver: Solver control, Solver run

• Results: Purge, Show; Postprocessing: Apply changes, Pipeline from result, Create warp vector filter, Create scalar clip filter, Create cut filter, Create clip filter, Create data along line filter, Create linearized stresses,

Create data at point filter, Create functions

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

---

• Additional: Preferences; FEM Install, FEM Mesh, FEM Solver, FEM CalculiX, FEM Project, 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

---

• Help: Tutorials, Video tutorials
• Workbenches: Std Base; Arch, Draft, FEM, Image, Inspection, Mesh, OpenSCAD, Part, PartDesign, Path, Points, Raytracing, Reverse Engineering, Sketcher, Spreadsheet, Start, Surface, TechDraw, Test Framework, Web
• Deprecated or unmaintained workbenches: Complete, Drawing, Robot

---

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

---

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