Forming a perforated sheet

[wiengines]

Someone asked me an interesting question which I did not have an answer for. So naturally, I figured I would ask you guys (and gals).

We take a piece of perforated sheet metal (.149in holes on .1875in spacing), and draw it into a round shape. So the question is there an easy way to model this so that each of the perforations are (relativly) close to where one would expect them to be after the part is formed?

The attached image shows the cross section of the formed part.

Chris T.
Project Design Analyst
Kohler Co. Engine Division
Using NX7.5

 

[Toost]

I have experimented a little with the metaform. It seems to do it.
It is a bit "volatile", if one sets the wrong input, it calculates "for ever".
The single sheet body in the image took a few minutes to calculate. ( Didn't clock it.)
Probably one can learn what to do and don't. In this case the shape that i formed to is a single b-surface sheet.
Don't know if this is better or worse.
Attached a 7.5 parasolid copy. ( model made in 8.5)

Regards,
Tomas

 

[wiengines]

That is exactly what I was looking for!

I've noticed that as well...if the wrong inputs are selected, it basically sits there forever. I'll keep playing around with it to see if I can get something that works

Chris T.
Project Design Analyst
Kohler Co. Engine Division
Using NX7.5

 

[Toost]

Btw, i noted that the option "delete holes"option will only ignore the holes when calculating, it still produces an output with holes. The calculation time for this piece goes "logarithmic" if it is not-selected.

Regards,
Tomas

 

[wiengines]

Thanks for the tip, that must have been my problem! When I create the metaform feature, the only thing that I see is a bunch of splines that are projected onto the target face. Is this correct, or should I be expecting a surface as the result?

Chris T.
Project Design Analyst
Kohler Co. Engine Division
Using NX7.5

 

[Toost]

What you should see while computing is a Finite Element Mesh that stepwise moves from the "flat state" over to the wrapped state, when that is done NX will create a new surface/ curve etc that has a matching deformation. See attached image of "early" screenshot.

Regards Tomas

 

[Toost]

This screenshot is "finished". Display Refresh will erase the mesh.

 

[SiW979]

As a rough guide to reduce the time it takes to calculate/process the metaform, get as rough idea of the over all size of the part then in under settings --> tolerance --> Linear, enter rougly 25% - 33% of the over all size (if the part is roughly 1000mm max size, enter 250mm or 350mm as your linear tolerance), you can then reduce this after each pass until there is no marked improvment in the preview.

Best regards

Simon NX 7.5.4.4 MP8 and NX 8.5 (native) - TC 8

http://www.jcb.com