Wall Critical buckling load and length

[mustafahesenow]

Hi all

Is there a way to calculate the critical buckling load and the critical buckling length for wall .

similar to critical force table for bar .

[Artur.Kosakowski]

Hi @mustafahesenow

The buckling analysis should give you the critical coefficient which then you can use to determine the buckling length.

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[mustafahesenow]

Hi @Artur.Kosakowski

thanks for the answer.

its almost similar to punching case.

Its easy to determine it for the wall so why couldn't include it for walls also.

You have P from Reduced result .

Then  Pcr= Critical coeff x P

Then KL= 3.14 x (ExI / Pcr)^0.5

[Artur.Kosakowski]

Hi @mustafahesenow

For the same reason this information is not displayed by default for bars. The buckling analysis in Robot is not intended to determine buckling lengths of elements of a model as in the situation where there is more than one the values for the ones which don't buckle are incorrect. 

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[mustafahesenow]

Hi @Artur.Kosakowski

Could you please explain it more .

Sometimes I got k factor around 5 on building have only 4 floors which they are the upper columns and at the corners its really strange.

[Artur.Kosakowski]

Hi Mustafa,

Please check:

https://forums.autodesk.com/t5/robot-structural-analysis-forum/buckling-analysis/m-p/3300465

https://forums.autodesk.com/t5/robot-structural-analysis-forum/buckling-analysis/m-p/3300465 (post 2)

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.

[MartinTrs]

Hi @Artur.Kosakowski and @mustafahesenow

Is there a way of determining the exact location (node) and the exact internal force for which the critical coefficient is calculated and displayed in the table "Buckling analysis Results"?

The problem is that for walls with a lot of holes and different latteral supports it's very tedious to manually calculate the wall's buckling length. So in several cases I've created a separate RSA model for each of the "complex wall". With buckling analysis I can find the critical coefficient for each of those walls however to determine the exact buckling length I would also need the exact location and force for which the critical coefficient applies to.