defeature small feature in CAD model

Dear CAE experts:

Sometimes, I received CAD models from designers. These CAD model (say in step format) usually contains all the details, such as smaller fillets, smaller faces, small holes, small edges. For some analysis (CFD, thermal), these small features have little effect on result, but, makes meshing a nightmare. Is there any Open Source software that is capable defeaturing? Or a mesher that is capable of ignoring small features?

Thanks!

phsieh2005

Features aren't included in say the IGES or STEP models...you'd have to get them in their native formats and do the work in the corresponding program and re-export.

Pei-Ying Hsieh wrote:

Dear CAE experts:

Sometimes, I received CAD models from designers. These CAD model (say in step format) usually contains all the details, such as smaller fillets, smaller faces, small holes, small edges. For some analysis (CFD, thermal), these small features have little effect on result, but, makes meshing a nightmare. Is there any Open Source software that is capable defeaturing? Or a mesher that is capable of ignoring small features?

Thanks!

phsieh2005

In a windows environment, you can download and install Alibre Xpress for free. The free version has some few limitations compared to the commercial version (assembly up to 25 components, some features missing, etc), but it can be usefull for your scope.
Another free 3d-cad package is OneSpace designer Personal Edition (OSD-PE), but I don't know if it can export in step format. Alibre can do it.<br /><br />Post edited by: Alessandro, at: 2009/02/15 12:44

Hi,

Thanks for the reply! But, I am not looking for a CAD software. I already have SolidWorks. Some of the CAD model I received is in native SolidWorks format, but, there are times, I cannot simply delete/supress a feature because it affects other features downstream, hence, messing up the model.

What I am looking for is to defeature the model. That is, delete small holes/fillets automatically outside SoildWorks. I already found several commercial packages with the defeature capability, but, would prefer an Open Source software if one exist.

phsieh

If you already have swx, then you can use it to simplify the model: for example, if you want to suppress an hole, just add an extrusion of material that goes to cover the hole. You can do the same to cover fillets, chamfers, etc etc. Finally, when you export to step or iges, the model simplified by addition of features is exactly the same obtained removing feature from the model tree.
I have SolidEdge (very similar to SWX) and I do it in that way.

I hope this helps you.

Hi,

I found several packages that are capable of defeaturing:

CADfix
SpaceClaim
3D_Evolution

are the most impressed.

phsieh2005