Plate Lateral-Torsional Buckling

[engpes]

I am trying to determine the critical (lateral buckling) stress of a plate loaded parrallel to the plane of the plate(similar to a lift lug but longer moment arm.)

The cross section is not constant, and does have out of plane "flanges" (see attached sketch). I have determined the critical stress per AISC F11.2 for a rectangular bar with a constant cross section and this falls within the allowable limits for my particular loading case (albeit overly-concervative).

Is there a method for taking advantage of the wider cross section at the top of the taper, as well as the "flange" at the center (see attached sketch).

Thanks in advance