3.2 Flange local buckling

Introduction to flange local buckling

The fourth limit state for beams is Flange Local Buckling, or FLB for short. It is exactly the same as Web LocalBuckling, except the width-thickness ratio is in terms of the flange and not the web. This type of buckling occurswhen the width-thickness ratio is not large enough to withstand the moment on the beam. The way to prevent thistype of buckling is to limit the with-thickness ratio.

The limits can be computed for flange local buckling. The width-thickness ratio is compared to ${\lambda }_p$ and ${\lambda }_r$ . Then the maximum moment can be calculated.

Equations to determine flb

When,

When,

And finally, when