Equivalent Lateral Force Method seismic analysis 2D

[126872]

Hi
I have to make the comparison of results from Robot (using various types of analysis) and my own calculations (based of matrix displacement method). I had no problem with seismic analysis but when I want use equivalent lateral force method seismic analysis there were some complications. I have tried in many ways but I still get the same communique when I run analysis: "There are no nodes in the floor planes. It is impossible to apply forces for the static seismic analysis case."
I will be very gratefull if someone could tell me what I'm doing wrong.

[Artur.Kosakowski · Accepted solution]

Change the model to 3D Frame (Geometry > Structure type).

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[Artur.Kosakowski]

Corrected for 2D Frame models in Robot 2015.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.