No elements under compression to run buckling analysis Error.

[mr.co_su]

When I was trying to analyze the buckling of a compressed bar, robot structural analysis keeps telling me that there are no elements under compression although there is an element that's compressed. And I have got accurate results when i modeled the same bar in SAP2000.
The example: first Picture.

The model: second picture.

The error: third picture.

[Artur.Kosakowski]

Hi @mr.co_su

Could you attach the Robot model (rtd file)?

[mr.co_su]

Sorry for my late reply, I've attached the file.

Thanks!

[Artur.Kosakowski · Accepted solution]

Hi @mr.co_su

For such boundary conditions you have to have some nodes defined along the bar element:

I'm attaching the corresponding model too.

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.

[mgDDJJW]

Hello Artur,

I'm struggling with the same problem. In my model of 3D truss construction I have bars which are either tensioned or compressed, there's no doubt about it, but the solver always shows the message "No elements under compression to run buckling analysis".

I have already tried your solution proposed above to divide the bars into more elements and increase calculation nodes, but it seems to not work in my case - I keep receiving the same error message all the time.

I'm running out of ideas what could be the reason?...

Thanks in advance for any help.

Marcin

[Artur.Kosakowski]

Hi @mgDDJJW

Could you zip and attach the model?

[mgDDJJW]

Yes, sure. That's just the part of a bigger structure but shows the problem.

Thanks in advance!

Marcin

[Simau]

Hi @mgDDJJW

There is no load in case DL2, add selfweight

[mgDDJJW]

Gosh, how can be so blind?....

Many thanks @Simau

Marcin