Impact

The Impact Finite Element Analysis System

Welcome to the Impact Finite Element Program.

This program was designed to be a free and SIMPLE alternative to the advanced commercial Finite Element codes available today. The guideline during the development of the program has been to keep things clear and simple in design.

Impact has been designed to be easily extendible and modular to enable programmers a way to easy add features to the program without having to enter other parts of the code. Impact has been written in Java. This choice of language may seem strange at first, but with the recent development of Java engines, speed penalty is not that significant. On the other hand, the Object Oriented features and the high portability of Java is a clear advantage for the future.

Impact is a Finite Element Code which is based on an Explicit Time stepping algorithm. These kind of codes are used to simulate dynamic phenomena such as car crashes and similar, usually involving large deformations.

There are quite few explicit codes around which might seem strange since the other cousin (implicit finite element) are quite common. The implicit codes are used to simulate static loads in structures. Something that explicit codes does not manage very well.

Historical Information

The project was originally hosted here - https://sourceforge.net/projects/impact/

Also See

• Impact - Links
• Impact - Wiki

Note

I have put these pages together in an attempt to recover this software. The following is a reconstruction of the original Wiki extracted from te Way Back machine (Internet Archive) Impact Wiki Reconstruction

PLH Nov 2025.

Updated java Code

An updated copy of the Java codebase can be found here - https://gitlab.com/impact-analysis/impact-java-2025

I have corrected a bunch of typos and done some refactoring to use more modern Java syntax and address IntelliJ warnings, however, much remains to be done in some of the codebase.

I have also added a bunch of other stuff which I have been using to experiment with - https://gitlab.com/impact-analysis

Possible Improvements

A number of improvements came to mind as I was working through the code, including:

• Replace or augment .in files with .yaml or .json equivalents with appropriate utility methods to work with these
• Provide alternate GUI implementations using more modern languages - Swift/SwiftUI, go, rust, C#.

 I have some experiments which I will push to the GitLab.com/impact-analysis project