Question:
The lateral torsional buckling (LTB) check is missing in the Steel Design. What is the reason?
Answer:
► Image | Sections https://www.dlubal.com/en/img/053176
For sections with I-z I-y (member no.1), LTB check is provided according to the selected standard.
For sections with I-z I-y and no bending about the z-axis (member no. 2), there is no need to check for LTB.
For section with I-z less than I-y and bending about the z-axis (member no. 3), “Non-designable” error is listed.
Lateral torsional buckling (LTB) phenomenon in general is limited to major axis bending. For uncommon cases where minor axis bending is a concern, the code does not provide standard formulas to handle such cases.
It is currently not possible to check LTB for minor axis bending in RFEM. This is something that we may consider implementing in the future.
► Image | Design Checks https://www.dlubal.com/en/img/053177