Free Finite Element Program 3

[steveyeung]

Hi,

Does anybody know a good but free finite element program for

1. Elastic Analysis
2. Creep Analysis

for bridge engineering.

The important point is the program has a strong meshing capability...

 

[johnhors]

You could try looking at the list of free FEA tools given at:-

http://www.dermotmonaghan.com/

http://wwwLinks/index.php

Some of those listed like Calculix (an Abaqus clone) have very good solvers, expecting something like creep analysis from freeware is a tall order and Calculix is the only one I know of worth investigating for that. But I've never seen any freeware that is really good at meshing (yet !), and be warned free-ware will never compare well with a commercial offering.

You might consider one of the lower cost FEA packages instead:-

GiD -

http://gid.cimne.upc.es/index.html

FemDesigner -

http://www.femdesigner.co.uk

Roshaz -

http://www.roshaz.com

 

[steveyeung]

Thanks,

The major problem of freewares is it is difficult to install....because we are used to unzip the files and Windows does the rest of the installation.

Just for my information, is Linux very common in your country. In the UK, it is not very common

 

[johnhors]

Well my country is the UK !

Don't let Calculix being Linux based put you off if that's your concern, as I have only ever used the windows port of the code. I heard about the code from a colleague who had visited an office that had one licensed version of Abaqus but had also installed Calculix on every PC (as it's an Abaqus clone). Every PC only had the Linux OS along with StarOffice etcetera and all the useful free stuff installed, and that was in the UK !

 

[Steelforbrains]

Has anyone tried the software recommended by johnhors. Can anyone suggest which of these is best... I have tried some of the dozens of free FEA software programs on the internet only to find that most of them are... less than satisfactory. I need a program to design simple beam structures on concrete slab foundations (mezanines, bridge crane structures, etc...). I do not need to design intricate parts. I would definitely like it to be Windows "friendly". Any help would be appreciated.

 

[crisb]

Steelforbrains

For very simple beam analysis I recommend DTBeam. You van vary the supports and section properties and have answers in seconds.

http://www.dtware.com

 

[mrMikee]

Try the following...

thread404-128331

http://www.freebyte.com/cad/fea.htm#fea

I have both CADRE Lite and CADRE Pro and I think they a pretty good programs. There is an evaluation version of Lite for free that may suit your needs. Only the Pro version has plates. No creep analysis however.

http://www.cadreanalytic.com

Regards,
-Mike

 

[Steelforbrains]

Thanks crisb.
I have made an excel file that does simple beam stresses and deflections but it does not have a nice GUI like this program seems to have. Does anyone know of any similar program for column/baseplate design. Whenever I try to do simple column buckling analysis using things like Euler's formula, I come up with unreasonably small members. I am not sure as to how I should add lateral forces to my analysis. Should I try to determine a Von Mises stress from the axial and lateral loads? If I do that I am determining failure due to yielding and not buckling which seams to be a different type of failure. I now read the thread from MrMikee and I will check that out too, thanks.

 

[mrMikee]

Steelforbrains,

When you have both axial and bending stresses you need to check the combined stresses per Chapter H in the ASD manual (allowable stress design) or the comparable part of LRFD. Von Mises stresses are seldom checked for building type stresses.

-Mike

 

[steveyeung]

johnhors,

I had a look at Calculix's website, the procedures of the installation look a bit unfamiliar…..

 

[johnhors]

Steve

Are you looking at the procedure for Linux installation ?

Under windows you only require the two files:-

ccx_1.4.exe
cygwin1.dll

You can then use Roshaz for pre and post processing.

There is also a full windows installation available if you prefer.

 

[israelkk]

johnhors

Where this "full windows installation" located?

 

[johnhors]

Israelkk

On page

http://www.dhondt.de/

there is the following line:-


An installer for CalculiX on Windows has been created by Jeff Baylor and is available at

http://www.bconverged.com/calculix

 

[israelkk]

Sorry, I found it but the documentation files give error when trying to uncompress them.

 

[johnhors]

Sorry Israelkk, but I just tested the install and have successfully downloaded and installed the product. The exe requires perl to be installed, but the documentation gives me no problems.

 

[Steelforbrains]

perl?

 

[johnhors]

Steelforbrains, I clicked on the icon for "test calculix 1.4" by mistake , which uses a perl script. The exe's as installed work fine otherwise.

 

[steveyeung]

johnhors

I went to

http://bconverged.com/calculix/index.php

and downloaded an exe file " CalculiX_1_4_win_005.exe"

Later I downloaded ActivePerl 5.8.7.813 from

http://www.activestate.com/Products/ActivePerl/

After all installation, I found Calculix was not working properly.....

There were three problems/questions:
1. Is it necessary to download this file cygwin1.dll? If so, how to download this file and where is it saved?

2. I did a trial run as recommeded by the program documentation. In the command windows, I typed cgx result.frd. However, the output was not what I expected
Firstly, the word "Main Menu" didn't appear on the left hand side of the graphic window (Calculix Graphix). Secondly, a message came up in the common window which was
------------------------------------------------------
GLUT: Warning in C:\Program Files\CalculiX\cgx_1.4\cgx_1.4.exe: glutReshapeWindow: non-positive width or height not allowed
------------------------------------------------------

3. Back to the web page

http://bconverged.com/calculix/index.php,

it states that ""The documentation link within CGX requires a browser path be defined. This path ought to be set in CalculiX/common/site/cmdStartup.bat"". However, I don't know what I should do.

 

[johnhors]

Steve

1). Yes you require cygwin1.dll, a google search reveals several sites to download from, one is:-

http://www.dll-files.com/dllindex/dll-files.shtml?cygwin1

Place the dll in the same directory as the calculix solver.
You can then run the solver using Roshaz for pre and post processing.

However the windows installer from

http://www.bconverged.com/calculix

should have included this dll.

I have tested this installation on two machines (XP and Win2K) and all works fine after installation (including the test of the installation when perl is also installed)

2). I tried cgx also and found it some what lacking as well, with the menu not appearing in the graphic window as you did but I didn't get the GLUT warning (which is an OpenGL error message). Also I had to fire it up from the DOS command line with the model to view as an argument on the command line, which is a rather cumbersome way of doing things. If you didn't get the cygwin1.dll , did you also not get the glut32.dll appear in the same directory as cgx ?

The command language that it uses is based on that used by Cadfix (formerly known as FAMbuild and FAMresult which was itself based on FemGen), and will be difficult for those unfamiliar with command line based programs.

3). From the Start menu to Programs to Calculix to Documentation , I had no trouble with the html help files.
The file CalculiX/common/site/cmdStartup.bat on my machines (which I have not modified) is :-

@echo off

rem Modify this file to change your startup settings for the CalculiX command window.

set HOME=E:\temp
set CALCULIX_ROOT=C:\Program Files\CalculiX
set PATH=%PATH%;C:\Program Files\CalculiX\bin;C:\Program Files\CalculiX\ccx_1.4;C:\Program Files\CalculiX\cgx_1.4
rem (the doc paths should be URLs in quotes and have a trailing question mark)
set CCXDOCS="file:%CALCULIX_ROOT%/ccx_1.4/doc/html/ccx.html?"
set CGXDOCS="file:%CALCULIX_ROOT%/cgx_1.4/doc/html/index.html?"
set BROWSER=c:/progra~1/mozill~1/firefox.exe

cd %HOME%

cls
echo.
echo CalculiX command window
echo usage: ccx jobname
echo (no extension)
echo.
echo usage: cgx [-b^|-g^|-c^|-duns2d^|-duns3d] filename [ccxfile]
echo (extension required)
echo -a auto-mode, geometry file derived from a cad-file must be provided
echo -b build-mode, geometry file must be provided
echo -c read an solver input file (ccx)
echo -duns2d read duns result files (2D)
echo -duns3d read duns result files (3D)
echo -g use element-group-numbers from the result-file
echo -stl read stl triangles
echo -v (default) read a result file in frd-format and optional a solver
echo input file (ccx) which provides the sets and loads used in the
echo calculation.
echo.
echo usage: acis2fbd ^< infile.sat ^> outfile.fbd
echo.
echo usage: vda2fbd infile.vda ^> outfile.fbd
echo.


However I use Roshaz both to create input models for Calculix and to display the results.

 

[jbaylor]

Hello,

I wrote the Window's port for CalculiX, and do not mind helping you get it running. Also, if you have found some bugs, let me know and I will try to get them fixed.

I have not seen the GLUT error before. Would you check that glut32.dll is in:
C:\Program Files\CalculiX\cgx_1.4\
Does the CGX window still appear and function when this error is displayed? What OS are you using?

The menu functionality and the requirement of a command line execution are a bit unusual for a Windows application. I did not change any of the functionality from the UNIX version yet. My goal was to port the application from UNIX unchanged, and then update to improve the usability for the Windows users.

You can get to the menu once you have started CGX by using the left mouse button in the left border area. This space on the left side of the window is for contour maps.

The documentation is accessible via Start menu short cuts as well as from within CGX. If you want to open them from with CGX, you have to make sure the path to your browser is correct in the file:
C:/Program Files/CalculiX/common/site/cmdStartup.bat
I have it set for Firefox by default. If you use IE, you need to change the path. There is also a change that I will be making in subsequent releases. The way the browser is started right now, it does not release control back to CGX until it is closed. This can be fixed by changing the path to:
set BROWSER=start c:/progra~1/mozill~1/firefox.exe
for IE:
set BROWSER=start c:/progra~1/intern~1/iexplore.exe

Also, only the CCX testing script requires Perl.

I hope this will help.

Regards,
Jeff