Cancel
Showing results for 
Search instead for 
Did you mean: 

NonManifold Add troubleshooting suggestions?

Valued Contributor
Valued Contributor

I am trying to connect a bunch of surfaces using non-manifold add.   Somewhere in stitching or previous operations it cannot connect everything.   I tried to extract and recover non-manifold add geometry to start over and do it piece meal, but it leaves some of them connected.  Using 11.2.2

 

Any good suggestions on how to best troubleshoot this?

6 REPLIES

Re: NonManifold Add troubleshooting suggestions?

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hello!,

All problems related with stitching nonmanifold geometry in general are related with TOLERANCE value used: the default 1e-6 is so tight, then I suggest to test with 1e-4, if not success then 1e-3 and so on. Please note that you don't mention the type of model you are doing: is not the same to make a FE model of a big vessel or a simply bracket, the tolerance value of geometry is not the same.

 

Also, I suggest to use first always command GEOMETRY > SOLID > STITCH, avoid to select branching-like or T-Joint like geometry, only for continuous surfaces, this way the STITCH command will do the job to properly define the normal of surfaces and create a body, next joint all using NONMANIFOLD command in case of geometry with T-Joint like geometry (like stiffeners, etc..).

 

Best regards,

Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: NonManifold Add troubleshooting suggestions?

Valued Contributor
Valued Contributor

Hello Blas!   As usual you are an amazing help....to the WORLD!  

 

The structure is somewhat complex and large (about 20 x 2 x 1 meters but modeled in inches and about 100 surfaces).  

 

I am trying different strategies to get it connected, but some of the bodies are made up of separate surfaces that I cannot seem to extract or recover so I can start over.   Any ideas?  I'm thinking I will simply copy and translate the surfaces, delete the originals and move back into position as separate surfaces.

Re: NonManifold Add troubleshooting suggestions?

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hello!,

The first suggestion is to update to new version of FEMAP V11.3, this new release is extremely prowerful dealing with complex geometry, the MESHING TOOLBOX "FEATURE REMOVAL > CURVES > COMBINE SURFACE" is an example, the new Parasolid geometry engine makes life easy to idealize, simplify and build complex geometry.

Best regards,

Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: NonManifold Add troubleshooting suggestions?

Valued Contributor
Valued Contributor

Hi AllTrans,

 

In addition to what Blas suggested about changing the tolerance, I have found that when dealing with multiple bodies adding one body at a time using non-manifold add also resolves the issue.

 

Let me know if that works out.

 

Regards,

 

Saptarshi

 

 

Re: NonManifold Add troubleshooting suggestions?

Valued Contributor
Valued Contributor

Thanks all for the suggestions.   It seems my original inquiry has a complicated solution. 

 

1.  I did start over and copied and extracted surfaces and moved them back to position.  In some cases I remade the surfaces.

2.  I stitched the flat surfaces together then used non-manifold add...only combining a few surfaces at a time.   I played with the tolerances, but kept them as small as possible as a first try.

 

I will have to play with 11.2.3, but I just installed 11.2.2. Smiley Sad 

Re: NonManifold Add troubleshooting suggestions?

Genius
Genius

I have found a silver bullet wrt. this nonmanifold add weakness. Instead of "Incremental" testing (the default) choose "Standard".

 

That has worked for me in the past on very complex sheet metal welded midsurfaced structures, when nothing else worked.

 

PS. 11.3 is now available.