This is the list of frequently asked questions for FElt

last modified: 25 Feb 2000
  1. What is FElt?
  2. Where can I get FElt?
  3. What machines does FElt run on?
  4. I think I found a bug, what now?
  5. Is there a newsgroup or mailing list for FElt?
  6. Why do the FElt components have such stupid names?

  1. What is FElt?
  2. FElt is a free system for introductory level finite element analysis. It is primarily intended as a teaching tool for introductory type courses in finite elements - probably in the mechanical/structural/civil fields. In a command line environment, FElt uses an intuitive, straightforward input syntax to describe problems. It also includes a graphical user interface for workstations that allows the user to set-up, solve and post-process the problem in a single CAD-like environment. The Windows interface, WinFElt, consists of an editor and an encapsulator for the command line applications. It has some graphical post-processing capabilties.

    From the end-user point of view, FElt consists of six programs: felt, burlap, velvet, corduroy, patchwork, and yardstick. felt is the basic command-line application; burlap is an interactive Matlab-like environment for scripting your own elements and analyses; velvet is the primary GUI interface into the bulk of the functionality in FElt; corduroy is command-line program for automatic element generation; patchwork is a command-line application for file format conversion to and from the FElt syntax; and yardstick is a simple program for problem scaling and unit conversion.

    Felt is the simplest - it takes a FElt input file and spits back appropriate ASCII based (tabular or ASCII graphics) results depending on the problem type. The command line application felt is the only interface of the three analysis engines (felt, velvet, burlap) that is available under DOS.

    Velvet is the most powerful interface into the pre-programmed functionality of FElt - it allows for complete graphical problem definition through pulldown menus, popup dialog boxes and an interactive drawing area. It offers all of the capabilities of both felt and corduroy and has several options for post-processing, including color stress plots for planar elements, plots of the displaced structure, animation, graphical time-displacement plots for transient analysis problems, graphical frequency domain plots of transfer functions and output spectra for spectral analysis, and graphical plots of mode shapes for modal analysis problems.

    Burlap is the most powerful interface in terms of raw FE computing power simply because you can make it perform analyses that are not otherwise available in FElt simply by scripting your own analyses algorithms in burlap's powerful Matlab-like syntax. You can also use burlap to try out new element definitions quickly and easily or to manipulate the results from one of FElt's pre-programmed analyses in a novel way that is otherwise not provided for.

  3. Where can I get FElt?
  4. The latest version of FElt, in all its incarnations, is always available via anonymous ftp from in pub/FElt. Information is available on the Web if you want to take a more serious look at some of FElt's capabilities before you actually take it for a test drive on your machine. There is an ftp mirror site at in pub/src/FEM/Felt.

  5. What machines does FElt run on?
  6. The complete version of FElt (including the X11 based graphical user interfaces) has compiled and tested on HPs, DECs, Suns, SGIs, Linux x86 and AXP, and IBM workstations. It should do the same on any reasonable Unix system with X11R5 or R6. In general we provide binaries for Sparc stations running SunOS or Solaris and x86s with Linux, but there is no guarantee that the binaries are as up to date as the source code. When in doubt just grab the source code and build it yourself - really, it's easy.

    DOS executables are available for the command-line applications felt, corduroy, yardstick, burlap, and patchwork. A simple graphical application, feltvu is also available. You need to have at least a 386 to use the DOS versions. As of v3.02 we have switched to DJGPP v2.0 and the DOS versions should run under Windows 3.1. Also as of v3.02, there are 32-bit Windows (95 and NT) versions of all the programs (including velvet). You need X server software to make velvet work of course. DOS versions are not available for releases after v3.02. For later versions you can compile it yourself or get WinFElt (which will continue to be supported).

Back to the FElt Demo Document.