Tag: FEM

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Software

FreeCAD

freecad-logo

FreeCAD is a free open-source parametric 3D CAD system and can be used by anyone to create 3D models.

http://www.freecadweb.org/

The current version of FreeCAD (0.15) was released on April 8, 2015 and runs on Microsoft Windows, Mac OS X and Debian based Linux systems.

It has been developed since 2001 and uses Open CASCADE[1] as it’s geometric modelling kernel.

To install the program, download the relevant package for your machine and follow the installation instructions.
http://www.freecadweb.org/wiki/index.php?title=Download

Then go to the getting started page for a quick introduction to the available tools.
http://www.freecadweb.org/wiki/index.php?title=Getting_started

There are a number of workbenches available for you to use. They are designed to present the tools you are likely to use when modelling for various particular purposes. You can also customise any of the workbenches to suit your own particular needs.

workbenches

  • Use the PartDesign workbench for creating mechanical models or any small scale object.
  • For working in 2D use the Draft or Sketcher workbench.
  • The Arch workbench is the one to use for Architectural models
  • Designing ships? then use the Ship workbench
  • etc.

Here’s an approach for creating a simple model,

  • Start the program
  • Select the Part Design workbench
  • Create Sketch
  • Create some Geometry

  • Close the sketch
  • Select “pad” command
  • Specify the length required

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  • Select a face of the model
  • Create Sketch
  • Create some geometry
  • Close the sketch

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  • Select the “create pocket” command
  • Specify the length
  • Close the dialog

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  • Select a face
  • Select the make fillet” command
  • Specify the fillet radius
  • Close the dialog

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There are lots of features available in FreeCAD, one that caught my eye is the FEM (Finite Element Analysis) module. This module supports the linear analysis of isotropic (uniform in all directions) material and the calculation of resulting stress (v.-Mises) and displacement. This module uses the Calculix[2] free, open-source Finite Element Analysis application.

FEM

Another interesting module is the Robot workbench although I haven’t tried this one out (yet)

http://www.freecadweb.org/wiki/index.php?title=Robot_Workbench

FreeCAD also offers an alternative approach to driving FreeCAD using the in-built scripting language. Python[3] is used as the scripting language and this allows you to enter modelling commands directly into the python console window.

FreeCAD source code is also available[4] and can be downloaded if you need it.

Footnotes:

  1. Open Cascade In 1993, Matra Datavision first created a software development platform for developing CAD applications called CAS.CADE – Computer Aided Software for Computer Aided Design and Engineering. Matra Datavision have a long history in CAD software dating back to the 1980’s and are perhaps best known for a CAD system called Euclid. In 1999 they published CAS.CADE as open-source software known as Open CASCADE and later, in 2004, it was renamed Open CASCADE Technology. Read more about the history of Open Cascade Technology at
    http://www.opencascade.org/about/profile/history/
  2. Calculix Find out more about Calculix at:
    http://www.calculix.de/
    http://www.dhondt.de/
  3. Python Read more about python in Wikipedia
    http://en.wikipedia.org/wiki/Python_%28programming_language%29
    or on the python web-site at
    https://www.python.org/
  4. Compiling the source code Detailed instructions for compiling the source code are available from the FreeCAD website.
    http://www.freecadweb.org/wiki/index.php?title=Compiling
    http://www.freecadweb.org/wiki/index.php?title=CompileOnWindows
    http://www.freecadweb.org/wiki/index.php?title=CompileOnUnix
    http://www.freecadweb.org/wiki/index.php?title=CompileOnMac