uniform thickness / constant radius bends(sheet metal/packaging/moulded plastic)

[roambotics_scott]

Precisely modelling deformations in arbitrary materials is hard, but there is a simple heuristic that can go a very long way: enforce uniform thickness (and, slightly more generally, constant bend radii)

To achieve uniform thickness, whenever there is a bend / fold, simply ensure that the inner radius is 0.5*t, the outer radius is 1.5*t, and the middle radius is simply t

The advantage of this for folding material is that there is no deformation along the midline and squeezing and stretching are balanced so unfolding / unbending by treating the midline as incompressible gives a good / general zeroth order approximation for many materials independent of their physical properties.

For a single bend (like the one shown here), if the thickness is t, the base, b, and the height, h, then the unfolded length of the cross section would simply be b + c (midline corner chord length) + h.

If the bending radius at the midline is r, then the midline chord length is just r * θ (bending angle in radians), in this right-angle case, θ = π/2

r can be chosen arbitrarily and this approximation will be excellent for any bendable material when r ≫ t, and good for many materials in the uniform thickness case (r ≅ t).

This works well enough for folded paper that die lines can be cut based on it with reasonable confidence that the final folded parts will fit together, and it would probably be a great starting point for bended metal (and it could be generalised by adding a fudge-factor function / lookup table)

The uniform thickness case would also be extremely useful for moulded plastic parts because uniform wall thickness means uniform flow (avoiding weld lines and flow marks) and uniform deformation (avoiding warpage) on cooling. 

[kb9ydn]

So what is the actual program feature/function that you are proposing?

C|

[roambotics_scott]

Easily building (and unfolding) uniform thickness sheets, @kb9ydn

[kb9ydn]

Ahh, ok.  So it would be part of the "sheet metal" functionality, but really would work for any type of folded sheet design.

C|

[roambotics_scott]

Yeah although this would be a simple / easier to implement approach for unfolding (though it does also happen to be useful for moulded plastic design)

[keqingsong]

Hey there! Thanks so much for submitting your idea. Unfortunately, this idea did not get a lot of votes from the community, and now is 2 years old. We're changing its status to archived. If you still feel strongly about this idea, you can resubmit it. Check out some idea submission best practices here: https://forums.autodesk.com/t5/community-faq/ideas/m-p/5384681#M44