Calculix: A Free Software Three-Dimensional Structural Finite Element Program

CalculiX is a package designed to solve field problems. The method used is the finite element method. With CalculiX, finite element models can be built, calculated, and post-processed.

The pre- and post-processor is an interactive 3D tool using the openGL API. The solver is able to do linear and non-linear calculations. Static, dynamic, and thermal solutions are available. Both programs can be used independently.

Because the solver makes use of the Abaqus input format, it is possible to use commercial pre-processors as well. In turn, the pre-processor is able to write mesh related data for Nastran, Abaqus, Ansys, Code-Aster, and for the free-CFD codes Dolfyn, Duns, ISAAC, and OpenFOAM. A simple STEP reader is included. In addition, external CAD interfaces are available.

The program is designed to run on Unix platforms like Linux and Irix computers, but also on MS-Windows.

The CalculiX package was developed by a team of enthusiasts in their rare spare time. They are employees of MTU Aero Engines in Munich, Germany, which granted the publication. Contact information can be found at the bottom of the "Download" page.

Example: Small Jet Engine Investigation

For a quick overview of the capabilities of CalculiX, the results of an investigation of a small jet engine are presented. The jet engine was built around a turbo-charger rotor in the early 90's by Andreas Funke and the author Klaus Wittig. The FE model was built from scratch with CalculiX, and the compressor and turbine models together with solver input files can be found in the distribution.

The calculations were done to determine the burst speed and the highest allowable rotational speed concerning low cycle fatigue and creep. In addition, the eigenfrequencies were calculated to determine possible resonances with the vanes.

The models are meshed with 20-noded brick elements with reduced integration. The right and left side of the disks are connected by cyclic symmetry equations, which allow calculating eigenvalues and mode shapes for certain nodal diameters of a rotational symmetric volume based only on a segment of the structure.

The compressor is made of casted aluminum alloy (AlSi - C355) and the turbine of a high temperature alloy (Inco 713C).

Resources and Links

• Click HERE for the jet-engine-model and documentation
• Click HERE to see the example of the turbo-charger compressor
• Click HERE to see the example of the turbo-charger turbine
• Click HERE for further examples (with thanks to Prof. Martin Kraska, Brandenburg University Of Applied Sciences)
• Click HERE for DOWNLOADS and to see more about the finite element and graphic capabilities of CALCULIX
• Click HERE for the list of professional CalculiX users who contributed to the development

License

Copyright (C) 1998 Guido Dhondt and Klaus Wittig

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.