Force application on a random point in a diaphragm

[Anonymous]

Hi All,

Is it possible to place a point load on a random point of a diaphragm?

I tried to do that by  using "force in point", but I get a warning "Load has not been distributed correctly - there are no objects or elements carrying the load overlap". See attached Sketch. It seems that the force assignment cannot be linked to any element.

I tried another thing:
If I try to define a diaphragm by myself, to get a point where I could apply the load, I noticed that Robot also tries to automatically create a diaphragm but fails as I already linked all points to my master node. I see that Robot creates some sort of support remnants at the point where Robot master node was supposed to be. When I run the modal analysis with this setup, I get strange results. Total modal mass is much less than when Robot is allowed to automatically create the diaphragm. So I am afraid to use this solution .
See MESSAGE 20 OF 24 at
https://forums.autodesk.com/t5/robot-structural-analysis-forum/api-diaphragmer-work-with-diaphragms-...

Model attached.
 

Thanks,
Alex

 

[Anonymous]

Further to the above post, I tried to split the diaphragm at the point where I would like to apply the force. As a result, I get a lot of instability warnings. Secondly, the sum of applied forces and the sum of reactions does not match. 

Why is that?