Impact - a Free Explicit Dynamic Finite Element Program

Impact is an open source finite element program suite which can be used to predict most dynamic events such as car crashes or metal sheet punch operations. They usually involve large deformations and high velocities.

Simulations are made on a virtual three dimensional model which can be created with a pre-processor or with the built-in Fembic language. Results are viewed in a post-processor.

Impact is designed to interface with the included pre- and postprocessor by default, but there are also interfaces available for more advanced pre-and postprocessors such as GiD or Gmsh. Impact also has rudamentary support for Nastran file format.

Development is made by a team of volunteers from all over the world with the aim of creating a clean and compact program which is simple to understand and use.

Impact is licensed under the Gnu Public License which makes it free to use and modify as long as you release and publish your improvements under the same license.

Impact is written in Java which means it can be run on most hardware and operating systems.

Getting started

Screenshots, Tutorials and Examples available at the Wiki. If you like what you see you will find download and installation links here on this page.

NEWS

2007-07-11 New version 0.7.5

2007-06-14 New version 0.7.4

2007-06-02 New version 0.7.3

• parser for UNV files (Salome interface)
• parser for BDF and NASTRAN
• parser for GMSH version 2. This time it will read raw mesh data for simpler interaction.

Old news

Download & Installation

You need to install the following to get started with Impact:

• A Java Engine You can take either the Runtime environment (JRE) or the Development Kit (SDK).
• The Impact Program

Impact has built in model creation and result viewing, but there are more powerful alternatives available. Gmsh is a free pre-processor which can be used to build Impact models

• Gmsh Preprocessor
  

Optionally, you can create models and/or view simulation results with a powerful commercial program which also has a limited free license for academic purpouse:

• The GID Pre and Postprocessor

If you plan to run Impact on a cluster network, you will require JavaParty to be installed and functioning first.

• JavaParty home page (for documentation)
• JavaParty program version 1.09 (for download and installation)
  

• ImpactGUI.bat / .sh    - Starts the Impact GUI environment (recommended)
• ImpactGL.bat / .sh     - Starts the Impact GUI with accelerated graphics
  
• Impact.bat / .sh          - Starts only the solver or translator
  
• ClusterGUI.bas / .sh   - Starts the GUI but on a Cluster network
• Cluster.bat / .sh          - Starts solver or translator but in a Cluster network

Documentation

Documentation of the GUI Pre- Post and Graph modules as well as all commands for the solver is available in the help section of the GUI. Just start the GUI environment and select the help tab to get this information.

This documentation is also available online together with tutorials and examples on the ImpactProgram wikispace. You may add your own documentation there as well.

If you like a different format like pdf or similar in order to easily print the manual, you can use the excellent htmldoc utility. The maual is written with this in mind and will allow a nice printout after conversion.

Feedback & Contact

• Subscribe  - Get notified when new versions are released
• Help  - Join the mailing list discussion and get answers to your questions
  
• Report a bug  - So that we can fix it for the next release
  
• Request a feature  - We might implement it in the future
  

Personnel

Join the Impact team

Impact is available for free and is open source which means you are free to change it as long as you make the changes available for free to others.

You are welcome to join the develpment of Impact. We are especially looking for

• Beta testers
• Developers
  

If you are interested then have a look at the release plan to the left here, pick an item to contribute on (or propose a new one for yourself) and finally go to the project page and send the administrator a note! We'll review it and respond to you as quickly as possible.

Links & References

Impact & the Impact team uses the following excellent software:

• Catweb PNG encoder - For picture export in the postprocessor
• Excelsior Jet Java compiler - For the faster native versions of Impact
  
• Jama Matrix manipulation library - For the solver mathematics
  
• JavaParty cluster framework - For the cluster version of the solver
  
• JMP Java Memory Profiler - For speed optimization
• Alan Kaminsky's Downhill Simplex Method Implementation - For geometry intersections
• The JoGL OpenGL bindings - For hardware accelerated 3D graphics
  

Here is a list of usable links if you like what you see and want to find out more.

Screenshots & Examples

Simulation of a bumper beam low speed impact test

Pressing of a cup

Screenshot - Plotting a curve with the built in grapher 

Papers & Litterature

This section is reserved for papers and presentations where Impact has been used.

• Integrating GiD and Impact Paper presented at the 2:nd GiD Conference
  
• Integrating GiD and Impact Presentation material for the above

• Dyna 3D Theory Manual This theory base applies also to Impact in most parts