FEM CalculiX: Difference between revisions

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=== Preface === <!--T:2-->
== Preface == <!--T:2-->
This page collects all informations about the current solver used by FreeCAD's [[FEM Module|FEM Module]]. The interface between the solver and FreeCAD in pre- as well as post processing is also described. At the moment (Begin 2016 and FreeCAD 0.16dev) the only supported solver by the FEM Module is [[http://www.calculix.de/ CalculiX]]. Depending on the operating system you are working with you need to install CalculiX first. Check out [FEM Install].
This page collects information on the [http://www.calculix.de/ CalculiX] finite element solver, the default solver in the {{KEY|[[Image:Workbench_FEM.svg|24px]] [[Fem Workbench|FEM Workbench]]}} for structural and thermo-mechanical analysis as of FreeCAD 0.17. Depending on the operating system you are working with, you'll need to install CalculiX before running your first simulation. Please see [[FEM Install|FEM Install]].


=== Interface === <!--T:3-->
<!--T:12-->
The solver is able to do linear and non-linear calculations, for static, dynamic, and thermal problems. The solver operates on an Abaqus input file ({{incode|.inp}}), which means it can be used with different pre-processors that support this format. The program includes its own graphical preprocessor which, however, is not used by FreeCAD, only the solver itself.
Interaction between FEM Module and CalculiX is done by text files. The FEM Module writes a CalculiX input file, starts CalculiX, logs the output of CalculiX and read the output files of CalculiX if they are available. The [[FEM SolverControl|FEM Control Solver]] tool manages the whole process. User interaction in the process is possible.


<!--T:13-->
==== Preprocessing interface ==== <!--T:4-->
CalculiX is designed to run on Unix platforms like Linux and Irix computers but also on MS-Windows. CalculiX was developed by engineers from MTU Aero Engines, Munich, Germany, to assist them in designing machinery such as jet turbines. The software is currently released to the public on the terms of the GPL version 2.
CalculiX uses abaqus input file format. The input file could be edited before the solver is started. The units used in the CalculiX input file are independet from the units used in FreeCAD. They will be mm and N. (ToDo: check this. What happens with the mesh if inch is used in FreeCAD. Density was introduced. With this we have kg and s and no longer N?! how about this !?!)


== Integration with FreeCAD == <!--T:3-->
The FEM Module - CalculiX interface supports the following objects:
Interaction between the [[FEM Workbench]] and CalculiX is done through writing and reading text files. The sequence of operations is as follows:
===== FEM Elements ===== <!--T:5-->

<!--T:10-->
# A CalculiX input file is created with details required to run the simulation
# The CalculiX solver is started with this input file
# The output from the solver is logged
# The output files from the solver are read, if they are available

<!--T:11-->
The [[FEM SolverControl|FEM Control Solver]] tool manages the whole process. User interaction in the process is possible.

== Preprocessing interface == <!--T:4-->
The input file that CalculiX uses can be prepared and edited before the solver is started. The units used in the input file are independent of the units set in FreeCAD; they will always be millimeters (mm) and Newton (N).

<!--T:14-->
{{Emphasis|(ToDo: check this. What happens with the mesh if inch is used in FreeCAD? As density was introduced, with this we have kg and s and no longer N?! how about this?!)}}

<!--T:15-->
The CalculiX interface supports the following objects:

=== FEM Elements === <!--T:5-->
* Tet4 and Tet10
* Tet4 and Tet10
* S3 and S6
* S3 and S6
* B31 and B32
* B31 and B32
* and those described in [[FEM Mesh CalculiX]]
* see [[FEM_Mesh_CalculiX]]


===== Analysis ===== <!--T:6-->
=== Analysis === <!--T:6-->
* linear static analysis
* Linear static analysis
* Frequency analysis
* Frequency analysis
* Coupled thermal structural analysis
* Coupled thermal-structural analysis

===== Materials ===== <!--T:7-->
* one linear elastic isotropic (uniformity in all directions) material
* multiple material is in development


==== Postprocessing interface ==== <!--T:8-->
=== Materials === <!--T:7-->
* One linear elastic isotropic material (uniformity in all directions)
read resulting stress (Von Mises) and all displacement
* Multiple material use is in development


== Postprocessing interface == <!--T:8-->
The FEM Workbench can read the resulting stress (Von Mises) and all displacements


<!--T:9-->
<!--T:9-->
{{FEM Tools navi}}
[[Category:Poweruser_Documentation]]
[[Category:Poweruser_Documentation]]
[[Category:Developer]]
[[Category:Developer]]

Revision as of 20:44, 1 February 2020

Preface

This page collects information on the CalculiX finite element solver, the default solver in the FEM Workbench for structural and thermo-mechanical analysis as of FreeCAD 0.17. Depending on the operating system you are working with, you'll need to install CalculiX before running your first simulation. Please see FEM Install.

The solver is able to do linear and non-linear calculations, for static, dynamic, and thermal problems. The solver operates on an Abaqus input file (.inp), which means it can be used with different pre-processors that support this format. The program includes its own graphical preprocessor which, however, is not used by FreeCAD, only the solver itself.

CalculiX is designed to run on Unix platforms like Linux and Irix computers but also on MS-Windows. CalculiX was developed by engineers from MTU Aero Engines, Munich, Germany, to assist them in designing machinery such as jet turbines. The software is currently released to the public on the terms of the GPL version 2.

Integration with FreeCAD

Interaction between the FEM Workbench and CalculiX is done through writing and reading text files. The sequence of operations is as follows:

  1. A CalculiX input file is created with details required to run the simulation
  2. The CalculiX solver is started with this input file
  3. The output from the solver is logged
  4. The output files from the solver are read, if they are available

The FEM Control Solver tool manages the whole process. User interaction in the process is possible.

Preprocessing interface

The input file that CalculiX uses can be prepared and edited before the solver is started. The units used in the input file are independent of the units set in FreeCAD; they will always be millimeters (mm) and Newton (N).

(ToDo: check this. What happens with the mesh if inch is used in FreeCAD? As density was introduced, with this we have kg and s and no longer N?! how about this?!)

The CalculiX interface supports the following objects:

FEM Elements

Analysis

  • Linear static analysis
  • Frequency analysis
  • Coupled thermal-structural analysis

Materials

  • One linear elastic isotropic material (uniformity in all directions)
  • Multiple material use is in development

Postprocessing interface

The FEM Workbench can read the resulting stress (Von Mises) and all displacements