Sorce Code Package 1

[blckwtr]

Hi, everyone...

I am not a scientist, I am a mechanical engineer with a few extra corses during my education regarding FEA. In my company we do occasionally some advanced calculations, but our budget isn't very large. The FE packages I come to think of is Abaqus and Ansys, but they are both relatively expensive. I know them well from my main thesis in university...

That's why I recently began some reserch on the internet. With some knowledge in programming you can actually generate a mesh from a given geometry, add some boundary conditions and solve with a mesh generator, solver, post processor etc, etc... (I am somewhat familiar with Fortran, and some other programming languages)

However, there is 100's 1000's of different source codes available, does anyone know of a "package" if you will that will fullfill any of the two mentioned "complete" programs, preferrably in Fortran...

How abaout the geometry input file? Which format must I generate? Does any mesh generators handles .step, .iges, parasolid, or any platform independent file types? And how do one translate these to a text file if necessary?

--Tommy--

 

[GBor]

Calculix (

http://www.calculix.com

or

http://www.bconverged.com)

is an open source, freely downloadable program with much of the functionality of Ansys for calculation. Roshaz (

http://www.roshaz.com)

is a very inexpensive front end that can do meshing, and many other pre- and post- processing functions. Roshaz has a solver, but it also interfaces with Calculix. For a very minimal price, you can have some significant capability.

Garland E. Borowski, PE
Engineering Manager
Star Aviation

 

[blckwtr]

Thank you very much, and these programs have a lot of capabilities... Just what I was looking for.

But the CalculiX, is it freely downloadable for Linux only?

 

[GBor]

I think

http://www.bconverged.com

has the windows version.

 

[blckwtr]

I found the Windows executable for CalculiX, but now I need a graphical interface...

 

[GBor]

Calculix has a GUI, but I haven't tried it in several years. When I did, it was TERRIBLE! It looks like bconverged has one on his site. No idea how good it is, but he is only charging $55 from what I can tell. Roshaz is excellent and currently being sold for $595 US. Anything else that will preprocess for Ansys will also preprocess for Calculix...they use the same file formats from what I understand.

 

[Onda]

Here you have a fast and completely free (under GNU/GPL licence) FEA package:

http://www.z88.org/.

Is not as good (meaning many possibility) as a commercial package but if You wont run only linear static analysis could be usefull.

Onda

 

[blckwtr]

Thank you, Onda for your reply. However, the GUI wasn't so user friendly... Maybe it will take a while to get used to. As far as I could see from a first glance you could import .dxf files, well OK...

It may be limited in possibilities, but if it can solve for non-linearities as well I best give it a shot...

thanks...

--Tommy--

 

[GregLocock]

I'm pretty sure z88 is a linear solver. There are a few non linear open source packages, but the ones I've come across are for particular fields of study rather than general purpose, and tend to be proof of concept rather than full products.



Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[blckwtr]

OK, I have done som research on this area now, and I have come to a point when I am determined to figure this out... Also I find it very interesting.

So far I have found a lot of solvers, no problem, but the solvers are useless if you can't discretize the geometry and read this to a input file together with material properties etc... Also, there are mostly unstructured tetrahedral mesh generators, not so many hexehedral or quad for 2D.

I come to think of one of our document templates which says; Always check drawings against surveyor's certificate of area measure, if not make it yourself...

By the way, the z88 is not a solver for non-linear problems, you are quite right... But I am in need of a mesh generator which can handle common files such as .iges .step .sat or something like that... That must be the first step for me...

--Thanks anyway...

 

[GBor]

blckwtr,

Don't know why I said, "Ansys" in my earlier post, Caclulix uses the "Abaqus" file format, but I guess you have already discovered that. From what I can tell, Calculix is your best option for a powerful, open-source code. As you have mentioned, however, it is useless without the ability to generate an input file. Since it's format is the same as Abaqus, the only two pre-/post- processors that will read in an IGES, STEP, or SAT and auto-generate a structured 3-D mesh are FEMAP and Roshaz.

FEMAP is expensive because it is very capable of reading and writing MANY formats and has a very easy-to-use GUI. Roshaz is more focused, and not quite as user friendly, but still is easy to use for everything that it appears you are trying to do. Both of them cost something, but are reasonably priced for what they offer. Of the two, Roshaz is the better value if it meets your needs (which it does for me). For Roshaz, you can download a node-limited version and request a 30-day trial. I believe FEMAP will send you a node-limited version as well.

Are you looking for a FREE, open-source, auto-mesh generator? I don't know of any quality FREE automeshers. In many cases, the automeshers and/or solvers are leased by the sofware company and embedded in to their GUI. Since they are paying for the solver, they have to at least charge an amount that they can regain their investment.

If this is market research to see if you can develop your own and market it, good luck...it's a tough business out there.