Generative Design surface modification

[Anonymous]

Hi All

I am using generative design to create a robot arm, which can be considered like a cantilever arm fixed at one end with a force applied at the other.

After computing a solution, I am performing an FEA analysis on the part to better understand the stress. There is a concentration of stress of one element at the fixed end, where the surface touches the preserve geometry. I know the bending moment is greatest here, but I think the localised high stress point is due to the sharp geometry in Image '3'.

However, when I try to modify this geometry, Image '5', I cannot change the surface (light blue outline) that builds upon the preserve geometry where the high stress is located.

How can I smoothen the feature so that a stress concentration does not occur where the organic structure meets the preserve geometry? I do not really care what it looks like, but smoother surfaces with a larger radii would decrease the stress.
Thanks

Toby

[jeff_strater]

If my memory is correct, I think the T-Spline edges that are inside of the Preserve are Frozen, and I suspect that is what is blocking you from editing them, and the adjacent faces.  I'm trying a simple case now to verify that and to record a video of how to edit those, but wanted to put this out first, in case that is the problem.  You should be able to just select that loop of edges, and in Modify, choose Unfreeze to get them editable:

One caveat:  Make sure those edges are fully embedded in the Preserve, otherwise the Boundary Fill will fail, which is why they are frozen in the first place, as kind of a guard rail against that kind of mistake.

[jeff_strater]

here is a screencast that illustrates that to edit the region adjacent to the Preserve, you need to first Unfreeze those edges: