honeycomb modeling

[mwnuk]

This is my first topic on Eng-Tips, so hello to anyone.

I've got a problem with modeling a honeycomb. I did one cell of honeycomb panel with some faces - which I need to have no double faces, when use pattern, and here everything is ok.

The problem starts with sewing all cells together. I extruded "L" direction foil in one operation, and "W" direction foil in second. I know that there are problems with sewing "T" surfaces, but I need to trim edges of panel, and cut place for insert in the middle. Does anyone know, what should I do to get a expected result?

Picture of trying add sew

 

[JohnRBaker]

This is a classic example of a non-manifold model. While there are several situations where this is an issue, the one you've run into involves attempting to create a model where a single edge is shared by MORE than two faces, which is not permitted when creating manifold geometry.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[Xwheelguy]

mwnuk,

If possible, you might want to describe a bit more in detail what the purpose of the honeycombs are - I understand you might be trying to simulate something that's "thin-walled" but the face to face measurement is 0 as you're modeling it, and other than for visualization, I do not believe that is realistic. If you were to allow a slight thickness between the honeycombs, then this wouldn't be an issue...even something as small as 0.001mm might work. If you do so, you may wish to start over with a Modeling Distance tolerance that at least equals your smallest distance. John may wish to elaborate, but I seem to recall that it was NOT recommended to change tolerances as you created features, hence why I suggested starting over.

Tim Flater
NX Designer
NX 7.5.4.4 MP8
WinXP Pro x64 SP2
Intel Xeon 2.53 GHz 6GB RAM
NVIDIA Quadro 4000 2GB

 

[JohnRBaker]

BTW, what version of NX are you running?

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[mwnuk]

I'm running NX 8.

I need this geometry to simulate a behavior of aluminium insert in sandwich material (cfrp + al honeycomb), with the potting material around insert. In simulation module there is no problem with that geometry to stich all with even automatic stiching, but i got a problem with trim honeycomb to size 140x140 and with cut foil around insert, because this is a pattern feature and it is not a single.

This is only a middle surface of honeycomb, where I'll put thickness in fem.

Finally I solved the problem in such way - i trimmed all faces with boundary edges of specimen, and hide faces I did not need (still with few problem with trimming). But if anyone knows better way to do what I need, please tell me.

Some screen shots to show the problem.

Thanks for answers

http://www.freeimagehosting.net/xf36n

http://www.freeimagehosting.net/iky4r

http://www.freeimagehosting.net/ra3zp