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Hi,
I am working a model and I am getting error 2809, it seems to be something linked to the Modal analysis as when I delete this, there's no issue. However, I need this one the analysis. I checked everything I thought.
Could someone help me with this? Not sure how to fix it.
Solved! Go to Solution.
Solved by Krzysztof_Wasik. Go to Solution.
Hi Model is not supported. It causes static instability. For such model program cannot calculate normal modes.
In my opinion supports are missing
I have deleted all load cases except load self-weight and run calculation. Refer to displacement presentation.
You have to define supports in the model. Otherwise all results will be incorrect.
I would recommend defining elastic support within slab 400 thk thickness label.
Refer to
How to apply soil elasticity on a raft foundation created as a panel in Robot Structural Analysis
Definition procedure is presented also in the following video
Hi @Krzysztof_Wasik, thanks for your response, I added the spring values to the raft slab. However, I am still getting weird values on my bending diagrams. Any idea why that could be happening?
Which is member number with weird results. Could you explain what you expect.
Hi @Krzysztof_Wasik.
I was expecting diagrams looking like the picture below as I didn't set up releases for my beams - the picture it is just an indicative from another model.
However I am getting bending (My) diagrams like this, it seems something is off with the model
Members 44 to 48 are connected to "wall" members. Moment shows interaction with wall finite elements.
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