Verification of hollow profile stability is not recognized as vulnerable to lateral-torsional buckling

Product Support
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1

In the verification ST3100.00, a hollow profile 140 x 70 x 4 (cold) is defined as a component susceptible to bending-torsional buckling and accordingly kzy is not reduced by 0.6 (Table 8.8 EC3-1-1). Is this an error on my part, or is it a mistake in the program?

3

Hi lschn,

Thank you for your message!

To analyze the problem more precisely, the model file would be very helpful:

:right_arrow: Click on File → Save As and choose the following settings to reduce the file size:
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:right_arrow: Then upload the file here (e.g. *.rf6, *.rs9) – this way the community can also contribute to the solution.

:owl: Don't want to share the file publicly? No problem – send it to me via direct message: click on my profile picture or my username → Message.

Best regards
Stefan Hoffmann

4

Support.rf6 (1,3 MB)

1 Like
5

Hi lschn,

Thank you very much for the file. It will be determined kzy according to Method 2 - as selected in Annex B. I do not see any storage related to the standard here:

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With Table 8.8, you are probably referring to the 2nd generation of the Eurocodes? We are working on an implementation here, but we do not yet offer this verification!

Best regards
Stefan Hoffmann

6

Thank you very much for the quick feedback. Attached is a printout from yesterday – identical hollow profile. It can be seen that the verifications were not adjusted for hollow profiles. Today's printout shows this adjustment (omission of bending-torsional buckling). Can the handling of a profile as a hollow profile be specifically excluded through a setting in RFEM, or what explains the difference in my output? Nothing was changed in the model (geometry).
Ausdruck_22_02_26.pdf (2.2 MB)
Ausdruck_23_02_26.pdf (2.4 MB)

7

Hi lschn,

In the buckling length settings, you can specifically control whether bending-torsional buckling should be considered.

You can find the corresponding option in the buckling length dialog. There you can activate or deactivate the consideration of bending-torsional buckling – depending on the desired design approach.

Further details can be found in the online manual:
:link: https://www.dlubal.com/de/downloads-und-infos/dokumente/online-handbuecher/rfem-6-stahlbemessung/000101

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If anything is still unclear or if you want to discuss a specific situation, feel free to get in touch! :+1:

Best regards
Stefan Hoffmann