FEM SolverElmer

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Solver CalculiX

Solver Z88

FEM

FEM SolverElmer
Menu location
Solve → solver Elmer
Workbenches
FEM
Default shortcut
None
Introduced in version
-
See also
Solver CalculiX, Solver Z88, FEM tutorial

Description

Elmer is an open source multiphysical simulation software mainly developed by CSC - IT Center for Science (CSC). Elmer development was started 1995 in collaboration with Finnish Universities, research institutes and industry. After it's open source publication in 2005, the use and development of Elmer has become international.

Elmer includes physical models of fluid dynamics, structural mechanics, electromagnetics, heat transfer and acoustics, for example. These are described by partial differential equations which Elmer solves by the Finite Element Method (FEM). https://www.csc.fi/web/elmer

Creating the SolverElmer object in the Analysis container in FreeCAD, gives access to the Elmer Equations for simple or multiphysical analysis.

Since FreeCAD already has an extensive integration of Calculix and Z88 as solvers for mechanical and thermo-mechanical analysis, Elmer will be preferred for Computational Fluid Dynamics (CFD), Heat, Electrostatics, Magnetostatics and Electrical Forces. It can also be used for mechanical FEA through the Elasticity equation or any combination of the aforementioned equations.

Installation

Elmer requires two components to be interfaced with FreeCAD:

• ElmerGrid is the interface handling meshes
• ElmerSolver is handling the computation.

There are standalone programs for both of these applications but their installation and usage are beyond the scope of the FreeCAD integration.

1. Go to the CSC binaries resources for Elmer: https://www.nic.funet.fi/pub/sci/physics/elmer/bin/ OR https://www.csc.fi/web/elmer/binaries
2. Download and install the version best suited to your Operating System (Windows 64 bits or Linux)
3. In FreeCAD go to Edit → Preferences → FEM → Elmer
4. Link the correct path for both ElmerGrid and ElmerSolver

   

   Above: Elmer preferences dialog menu showing fields to locate important Elmer binaries on Windows OS

You are ready to use Elmer in FreeCAD.

Usage

1. Switch to the FEM Workbench
2. Create an Analysis container by pressing the icon.
3. Create a FEM Solver for Elmer, by pressing the icon.
   • Note: A successful analysis will require at least a Model (2D or 3D), a Material (Fluid or Solid), a Mesh, Equations and Boundary conditions

   

   Above: Example of a tree view once a Solver for Elmer is activated

4. Edit the parameters for the solver in the Property editor Data tab of the SolverElmer object in the model tree view
5. Double-click on the SolverElmer object to prepare an analysis run

   

   Above: Dialog box to run an Elmer analysis

6. Select the path to write the analysis in by clicking ...
7. Click Write to write the case files in the directory selected previously
8. Click Run to start the analysis

About Equations

• Each type of analysis in Elmer is called an Equation (Flow, Heat, Electrostatics...)
• One or several equations can be used at once with Elmer by simply adding the Equation object under the SolverElmer object:

1. Click on the SolverElmer object in the model tree view
2. Select an equation:
   • Equation elasticity
   • Equation flow
   • Equation heat
   • Equation electrostatic
   • Equation fluxsolver

Notes

• Parameters for the Solver and for the Equations are independently set through the Property editor Data tab of their respective objects in the tree view.
• Each equation will have a priority, for example, if trying see the effect of a convective flow of hot air, the equation for Flow should be solved with higher priority than Heat, otherwise the solver will first solve Heat through conduction and then Flow.

Documentation

The following link gives access to the full documentation for Elmer https://www.nic.funet.fi/pub/sci/physics/elmer/doc/ This includes the manuals as well as tutorials. Note that documentation and files appended with "gui" generally concern the usage of the Elmer GUI and not the FreeCAD implementation of Elmer.

Solver CalculiX

Solver Z88

FEM

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