FEM SolverCalculixCxxtools

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FEM SolverCalculixCxxtools.svg FEM SolverCalculixCxxtools

Menu location
Solve → Solver CalculiX Standard
Default shortcut
Introduced in version
See also
FEM tutorial


CalculiXccxTools enables usage of the CalculiX solver. It may be used for:

  1. Setting analysis parameters
  2. Selecting working directory
  3. Running the CalculiX solver


  1. FEM SolverCalculixCxxtools.svg FEM_SolverCalculixCxxtools object is created automatically with creation of FEM Analysis.svg Analysis container. Otherwise use SolveSolver CalculiX Standard , or press S then X keys
  2. Optionally set data properties of the FEM SolverCalculixCxxtools.svg CalculiXccxTools object
  3. Double click on the FEM SolverCalculixCxxtools.svg CalculiXccxTools object
  4. Select type of the analysis
  5. Click Write .inp file
  6. Click Run CalculiX


By using Edit .inp file you can display and edit CalculiX input file manually before running analysis. In this case it might be useful to use parameter "Split Input Writer = true".


Default values can be set in the menu Edit → Preferences → FEM → CalculiX

  • DataAnalysis Type:
  • DataBeam Shell Result Output 3D: note that CalculiX internally expands 1D and 2D elements into 3D elements to accomplish FE analysis
    • false - results of 1D and 2D elements will be averaged to the nodes of original 1D or 2D mesh (i.e. purely bended beam will show 0 nodal stresses due to averaging)
    • true - resulting mesh will contain 1D and 2D elements expanded to 3D elements
  • DataEigenmode High Limit: Eigenvalues above this limit will not be calculated; Note: if eigenvalues of the model are above the high limit, CalculiX will finish without output
  • DataEigenmode Low Limit: Eigenvalues below this limit will not be calculated
  • DataEigenmodes Count: number of lowest eigenmodes to be calculated
  • DataGeometric Nonlinearity:
    • linear - linear analysis will be performed if model does not contain nonlinear material
    • nonlinear - nonlinear analysis will be performed
  • DataIterations Control Parameter Time Use
    • true - activates DataIterations Control parameter Cutb and DataIterations Control Parameter Iter
    • false
  • DataIterations Thermo Mech Maximum: maximum number of increments in thermomechanical analysis after which the job will be stopped.
  • DataIterations User Defined Incrementations:
    • true - automatic incrementation control will be switched off by DIRECT parameter
    • false - incrementation control will be automatic
  • DataIterations User Defined Time Step Length:
    • true - activates DataTime End and DataTime Initial Step parameters
    • false
  • DataMaterial Nonlinearity:
    • linear - only linear material properties will be included in the analysis
    • nonlinear - nonlinear material properties will be used from FEM MaterialMechanicalNonlinear.svg Nonlinear mechanical material object
  • DataMatrix Solver Type: type of the solver to solve equation system inside FE analysis. It may significantly affect calculation speed and memory demands. Suitability depends on your FE model and available hardware
    • default - automatically selects matrix solver depending on available solvers (probably it will be Spooles)
    • spooles - direct solver with support of multiple CPUs. Number of CPUs need to be set in Edit → Preferences → FEM → CalculiX → Solver defaults → Number of CPU's to use.
    • iterativescaling - iterative solver with least memory demands, suitable if model contains mostly 3D elements
    • iterativecholesky - iterative solver with preconditioning with and with low memory demands, suitable if model contains mostly 3D elements
  • DataSplit Input Writer:
    • false - write whole input into one *.inp file to be used by CalculiX solver
    • true - split solver inputs into more *.inp files, that can clarify hand editing
  • DataThermo Mechanical Steady State:
    • true - steady state thermo mechanical analysis
    • false - transient thermo mechanical analysis
  • DataTime End: time period of the step, used when parameter DataIterations User Defined Incrementations or DataIterations User Defined Time Step Length is true
  • DataTime Initial Step: initial time increment of the step, used when parameter DataIterations User Defined Incrementations or DataIterations User Defined Time Step Length is true
  • DataWorking Dir: path to the working directory which will be used for CalculiX analysis files.


When running a CalculiX, you might end up with error 4294977295. This means you don't have enough RAM space. You have then 2 options:

  1. reduce the number of mesh nodes, preferably by omitting geometry that is not absolutely necessary for your analysis
  2. buy more RAM for your PC


Original CalculiX documentation can be found at http://dhondt.de/ in the "ccx" paragraph.