Analytical model surfaces as plane elements in space

Dear All,

I am currently working on a project in Rhino/Grasshopper, which is exported using Mantis Shrimp into Revit by Dynamo and from here, I need to export it to a finite element program for analysis. I have succeeded in importing all the lines as truss elements, and have a fully connected finite element model, but I need the “floor element” as a shell element for stiffening my structure.

The problem is that this floor is not planar in GH, (it is just a representation, not the actual floor) it is curved a bit in space. I tried modelling the floor from a planar curve and then using Clockwork’s component “Floor.SlabShapeByPoints”, which works quite well. But the analytical part of the floor, does not follow the new shape of the floor, it stays planar. This can be seen on the picture as well.

My main problem is that i need the surface to connect to the nodes of the grid structure (the small blue Dynamo points in the picture), so it cannot be a big planar element as presented in the picture. It can however be smaller planar elements. I actually don’t need the floor itself, I just need the analytical part of the floor for my finite elements analysis.

In my other attempt I have tried to make the floor into smaller planar elements, so it is not one big analytical surface and I have tried to project the analytical model surface to “bottom of surface” or “top of surface”, but the analytical surface will not at any point move outside of the original plane .

I am relatively new in Dynamo, but more experienced in Revit in general. I have tried to do this both by components and by modifying Python scripts, but I have not been able to do anything about those analytical surfaces.

I hope that someone can tell me if this can be done at all, or can help me in any other way. Any help or suggestion is appreciated! Thanks a lot!

Best, Thea

Hi Thea

I don’t know if a DirectShspe will meet your requirement for an analytical floor for analysis
But it could be worth a try (DirectShape.ByGeometry)


Great, thanks!
I tried the DirectShape.ByGeometry component, and it works if i use “floor” as the category input. I can’t choose analytical surface - it comes with an error, that says that I have to choose a “top-level built-in model category”.
But for floors, it works. But the floor element generated is a bit weird i think. I cannot choose another type, and it has very few properties. I made the follwing definition:

Do you (or anyone) know if I can choose another type or familiy that have structural properties?

I’d imagine the only way to get multiple analytical surfaces like that, is to model a new floor for each individual face. DS elements can not be connected with analytical surfaces.

Hi, thanks for your reply!
I actually did try that approach as well, by dividing the floor in the same elements as shown on the polysurfae and then model them as individual parts, but I ran into the same problem as earlier, that the analytical surface does not follow the movement of the floor. Here is just seen two elements of the whole floor.

But I suspect that it’s not possible to move the analytical part out of the horizontal plane. That Revit has some kind of restriction, and that it’s just not a part of the structural floor elements, to be able to do that.

On second thought, it looks like analytical floors are always stuck to a horizontal plane :frowning:

What analysis software are you using? Maybe you can bypass revit and try to send the geometrical data directly to the analysis software.

I think that when using floor slopes the analytical floors follow the slope, but not when the sub elements are modified.

Yeah, that’s the same conclusion that I came to. I am using a software called FEM-Design by StruSoft, but the problem is that they have a export plug-in for Revit that reads the analytical model from Revit, and uses that as the model for the analysis, so I really need the analytical parts in Revit.
And I made a lot of other models at this point, so it is a bit too late to change software now. But thanks for your reply and confirming my theory that Revit only uses horizontal analytical floor. :slight_smile: