Area Load Grasshopper - strange behavior

Hi all,

I noticed strange behavior when defining area loads inside Grasshopper. Below is simple example just to show what exactly I mean. I have a slab (red) and area load (blue)

Now when I define area load it seams to be defined correct in Grasshopper preview (picture 1, bottom-right) but when I go in WINGRAF area load is covering complete slab (picture 2, right)

Whay that is happening and am I doing something wrong in my Grasshopper definition.
Is it posible to define a area load on a slab that has a hole?

Thanks a lot for all your help

Hey, I have never used GH and it is just a guess, but try to separate the loading into 4 pieces:

gh load


currently it is not possible to define a non-hosted area load (area load that does not reference to a StructuralArea with an Id) with holes in it, inside grasshopper.

One workaround would be the approach Kirill mentioned, to split the load, so that every piece does not contain a hole.

Another workaround would be to split the slab into two pieces. One part where the load is applied later on, an the remaining part. Then you can assign an Id to the StructuralArea where the load should be applied and use this area as basis for the AreaLoad component.

I hope this was helpful.

Best regards


Hi Kirill, thanks a lot for the suggestion, yes that is what I was thinking also but since in a real model there is a big number of holes separating the surface will be quite complicated

Hi Emanuel, thank you, if I understood you correct, I already tried your second suggestion. As shown above, blue is one surface and red is the second surface in Rhino. When I apply load to the only blue surface I get in Rhino preview the same shape as you are showing and I thought that everything was correct. But when I got to SOFiSTiK Graphic load is also applied to the inner area (bottom right picture)

I found a workaround to use negative direction load in the inner part and this way they undo each other

Hi Faruk,

make sure you create a StructuralArea (SAR) from the blue surface and assign an explicit Id to that SAR.
Then use that SAR for the AreaLoad component.
By doing this, the geometry of the area is exported inside an SOFiMSHC block.
The output of SOFiLOAD then refers to that SAR (hosted load).

If you dont assign an Id to the SAR or use the Rhino surface directly as input for the AreaLoad component,
the geometry of the load will be exported in the SOFiLOAD block, but here inner loops (holes) are not supported (non-hosted load).

Best regards


Thanks Emanuel, ID is the key solution and thanks a lot for the explanation