Allowable Compressive Stress on a Stiffened Cylinder

[RonMB]

We have a horizontal cylinder (simple beam)with longitudinal stiffeners along the top. We have a distributed load with the resulting compressive stress along the top. While the reviewing agency agrees that UG-23(b)(2) does not apply once the cylinder includes stiffeners, they do not agree that the allowable compressive stress then reverts to UG-23(b)(1). At this point they have no alternative and are asking us to provide reasonable and acceptable engineering references to support our case. I have been doing this for over thirty years and this is the first time the approach has been questioned.

Does anyone have anything I can cite.