Lateral torsional buckling checks (Composite beams: EC4 Eurocode)
You can switch off lateral torsional buckling checks by specifying that the entire length between the supports is continuously restrained.
If you use this option you must be able to provide justification that the beam is adequately restrained against lateral torsional buckling during construction.
When the checks are required you can position restraints at any point within the length of the main beam and can set the effective length of each sub-beam (the portion of the beam between one restraint and the next) either by giving factors to apply to the physical length of the beam, or by entering the effective length that you want to use. Each sub-beam which is not defined as being continuously restrained is checked in accordance with EC3 clause 6.3.2.3.
Tip:
As an alternative to using each beam's Properties dialog
box to set restraints and effective lengths, you can review and set more
effectively via Review View > Show/ Alter State. For more details see:
Review and
modify restraints and Effective Lengths and Factors - review and copy.