Simple free 2D FE triangle mesh generator?

[electricpete]

FE Newbie here.

I am looking for a simple tool to help me do 2D triangle mesh generation ?

The geometry I am interested in modeling is several sets of concentric circles adjacent to other sets (electric field model of several adjacent wires with insulation).

I checked the FAQ. Didn't see much there.

I searched the old threads and found one old thread where the original poster was looking for a very simlar thing
thread727-137588

Looks like the one's mentioned were calculix, z88, and some preprocessor for Franc2D

Since the thread is old, I just wanted to check if these are still good choices (or any other opinions or comments)

Thanks in advance

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[electricpete]

And I did want to re-emphasize simple.

All I need is a relatively easy way to generate node coordinates and list of which 3 nodes go with each triangle element.

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[GregLocock]

I haven't come across any new opensource FE preprocessors, if you have Matlab then OpenFEM /might/ have one.

I used to write them myself, back in the days when I got the boring jobs. We had to write them by hand because the element numbering defined the solution order and hence the wavefront.

An axisymmetric 2D mesh is going to be pretty straightforward, Excel might even be a good tool for it. You could use a robust node numbering methodology that generates telephone number length node numbers for each element, and then merge coincident nodes and do a renumber at the end.





Cheers

Greg Locock

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

 

[GregLocock]

I retract that. It is not necessarily easy! Sure the axisymmetry means you have only to solve each problem once, in theory, but there could be a nasty juggling act required to get a good quality mesh, unless you can afford to use a very high mesh density throughout.

Cheers

Greg Locock

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

 

[electricpete]

Thanks. I think I will give Matlab a try. I see it has Delaunay which will generate the triangles if I give it the points. I can guess where I need a dense mesh add a lot of points there, along with points on the boundaries of my shapes. Then examine the vertices of each triangle element with the function inpolygon to classify which ones fall in which regions of my problem. Looks like a lot of bookkeeping.

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[electricpete]

Also, I wouldn't call it axisymmetric. If I had only one wire with insulation, that could be axisymmetric. But I have multiple wires.

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[corus]

I have used GeomPack

http://members.shaw.ca/bjoe/,

which works quite well but you do have to download updated versions from time to time as the code runs out after a certain period.

corus