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Element names in Calculix

CalculiX consists out of two programs;

  • cgx: pre- and postprocessor
  • ccx: solver

A minor annoyance is that the naming of element types is not consistent between them.

Below is a table that provides a mapping between the two.

Please note that for mechanical analysis, second order elements are preferred above first order elements. Second order elements give more accurate results with fewer nodes and elements.

A regular mesh of C3D20R element generally gives the nicest results. If that is not possible, use C3D10 elements. Those can be generated from arbitrary geometry (e.g. from STEP files made with CAD software like FreeCAD) by gmsh.

Note that cgx cannot mesh all element types, and others need to be done in two steps. See the manual for details.

cgx ccx remarks
be2 B31 First order 2-node beam element. Don’t use for bending.
te4 C3D4 First order 4-node tet element. Too stiff. Use C3D10 instead
pe6 C3D6 First order 6-node wedge element. Use C3D15 instead.
he8 C3D8 First order 8-node brick element
he8i C3D8I Improved C3D8; reduced volume locking, no shear locking.
he8r C3D8R First order 8-node brick element with reduced integration
te10 C3D10 Second order 10-node tet element. Preferred if you can’t use C3D20R.
pe15 C3D15 Second order 15-node wedge element.
he20 C3D20 Second order 20-node brick element.
he20r C3D20R Second order 20-node brick element with reduced integration. Preferred
tr3c CAX3 First order triangular axisymmetric element.
qu4c CAX4 First order four-sided axisymmetric element.
qu4cr CAX4R First order four-sided axisymmetric element, reduced integration.
tr6c CAX6 Second order triangular axisymmetric element.
qu8 CAX8 Second order four-sided axisymmetric element.
qu8r CAX8R Second order four-sided axisymmetric element, reduced integration.
tr3e CPE3 First order triangular plain strain element. Preferably use CPE6.
qu4e CPE4 First order four-sided plain strain element. Preferably use CPE8.
qu4er CPE4R  
tr6e CPE6 Second order triangular plain strain element.
qu8e CPE8 Second order rectangular plain strain element.
qu8er CPE8R Second order rectangular plain strain element, reduced integration.
tr3s CPS3 First order triangular plain stress element. Preferably use CPS6.
qu4s CPS4 First order four-sided plain stress element. Preferably use CPS8.
qu4sr CPS4R First order four-sided plain stress element, reduced integration.
tr6s CPS6 Second order triangular plain stress element.
qu8s CPS8 Second order rectangular plain stress element.
qu8sr CPS8R Second order rectangular plain stress element, reduced integration.
tr3 S3 First order 3-node shell element. Preferably use S6.
qu4 S4 First order 4-node shell element. Preferable use S8.
qu4r S4R First order 4-node shell with reduced integration. Preferable use S8R.
tr6 S6 Second order 6-node shell element. Expands to C3D15
qu8 S8 Second order 8-node shell element. Expands to C3D20.
qu8r S8R Second order 8-node shell with reduced integration. Expands to C3D20R.

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