Lateral Torsional Buckling


New member
Oct 5, 2016
For both beams you are required to: -
Q6. Size an UKB that satisfies a deflection limit of δ<Span/300. -
Q7. Verify the cross-sectional resistance allowing for interaction if required. -
Q8. Verify the lateral torsional buckling resistance considering that lateral restrained is provided only by the primary beams (i.e. beams spanning from column to column). -
Q9. Discuss the results and propose changes that could be made if your calculations show that the sized profile in Q6 is inadequate.

I do not understand question 8. Would I just find the lateral torsional buckling of Beam 32. As it is a point load its effective length would be half of its original length, 12m so, the effective length would be 6m.

Do I also, find the LTB for Beam 34 as well even though it is not a primary beam. Or is it something to do with SLS, ULS or Steel Grade?

I know how to do LTB I just don't get what the question is asking me to do 11809