Aircraft sheet metal question

[slipstick]

I take it that Alibre isn't able to flange along a curve, such as required here, seen at section A-A? I haven't had any success as yet.

I can see a way to use a shell operation, but I don't have an unfold then.

 

[HaroldL]

That's not in Alibre's tool set - yet. Sounds like another Enhancement Request. (I know that SolidWorks can create the flange but I don't know that the flat pattern is very accurate.)
If you know the Bend Deduction, Bend Allowance or K-Factor for the material you could create your shelled component then create a new configuration and model the flat pattern. Or create the flat as a separate part.

 

[simonb65]

The problem is that the material needs to be stretched or compressed during a curved flange bend (which in the real world ends up in a curved former that needs to be crimped between rivets to flatten) ...



... so its more of a complex forming process than a simple bend. I've created ribs and formers using the solid approach using shell (after applying the external bend radius fillet. It only ends up creating a 3D model of the part and not a pattern you can use to cut blanks out of !



It would be a nice feature to add to sheet metal, as its used in all kinds of things like pressed enclosures with stiffening flanges and lightning holes.

 

[HaroldL]

Here is an example of how this may be addressed - at least until Alibre can create flanges along curve edges.

Simon, I used your image to base my model on.

I make no claims as the accuracy of the model or the flat pattern in this example. It is presented here only to show a process that could be followed once all the correct size and bend data is applied.

 

[Nick952]

When I needed this, I had to first convert the outer surface to a Mesh (so in effect no "Material Thickness") , then buy and use this:- http://www.revcad.com/Sheet5/Products/SL50/Mesh_Unfolder/mesh_unfolder.html
But not sure if it will work on the areas that have "beaten round a former/pressed in a die" compound rads.
I think they do a trial version to try out the software first.

I did submit a suggestion for Mesh Unfolding as an Alibre enhancment/ feature, but their reply was that there was "no intention of adding this"

Nick.

 

[slipstick]

Here is an example of how this may be addressed - at least until Alibre can create flanges along curve edges.

Simon, I used your image to base my model on.

I make no claims as the accuracy of the model or the flat pattern in this example. It is presented here only to show a process that could be followed once all the correct size and bend data is applied.
View attachment 25983
View attachment 25985

I had a missing model error upon opening this, although the drawing came through. Looks intriguing though!

EDIT: got the model to open. Interesting. Thanks!

 

[HaroldL]

I'll have to take some time and document this as a tutorial. There are more than likely parts other than aircraft ribs that could be created using this technique.