I wonder how to interpret notes 2 and 1. If your panel for shear buckling is between stringers does this conflict with note 2 ?

If Fscr > 0.5*Fcy, then FsPB = Fscr … interesting.

another day in paradise, or is paradise one day closer ?

Koji.K

That is a curve from the Vought manual and is used to obtain Fspb to ensure no permanent buckling of the web at limit load.

Crackman

Thanks for your imformation.
I wanted to know what test data the figure was made from, but according to other threads, unfortunately the manual is not available and cannot be seen.

why not take the figure at face value ?

Why not use it to say, conservatively, that FsPB = FsCR ?

another day in paradise, or is paradise one day closer ?

Guys... SWAG... At the end of each sub-section in there is a short section labeled REFERENCES. Perhaps the answer lies within one of those references.

NOTE.
Awhile back I was looking for a TOC and/or index to my Bruhn 1973 revision.

I found/downloaded the TOC embedded in a 119-page 'supplement' document approved by a Bruhn family member...
"A SUPPLEMENT TO ANALYSIS AND DESIGN OF FLIGHT VEHICLE STRUCTURES" [William F. McCombs]

I also found/downloaded a 309-page document...
"ERATTA - A Companion to Analysis and Design of Flight Vehicle Structures by Elmer F. Bruhn, PhD" [Bill Gran, GRAN Corporation]

I just checked the SUPPLEMENT... it looks like some REFERENCES were added many of the sections where references already existed.... perhaps there is more enlightenment in the Supp and/or the ERATTA...

Unsure of where these [2] documents came from... but I think it was the company library. Hesitate to post thee [2] documents directly to this thread [proprietary?]

NOTE/FYI. These few other references may/may-not shed some light on the topic...

"AFFDL-TR-69-42 STRESS ANALYSIS MANUAL" [Maddux, Vorst, Geissler, Moritz] [AD759199]

"Airframe Stress Analysis and Sizing" [CY NIU]

For now, I've gotta-go... some 'company work needs gitting done'.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

Regarding "A SUPPLEMENT TO ANALYSIS AND DESIGN OF FLIGHT VEHICLE STRUCTURES", Bill McCombs used to sell it directly to you. But that was over 15 years ago and may no longer be an option. I believe he worked for Vought.

Brian
www.espcomposites.com

if the original is no longer available, does the copyright still apply ? ie can we post a pdf ??

another day in paradise, or is paradise one day closer ?

I believe he passed a way many years ago. I also believe the US protects copyright after the author's death for some number of years.
Try the number below; see who answers:

William F. McCombs
2106 Siesta Drive
Dallas, TX 75224
Tel: 214-337-5506

See also:
https://www.eng-tips.com/viewthread.cfm?qid=112697

www.sparweb.ca

Oh well, whether you believe in copyright or not, it's already been on Archive.org for years. Can be found with the simplest of google search.

www.sparweb.ca

The following Bruhn's and Bruhn's supplement references were searched, but the source of Bruhn's Fig.C11.46 could not be found.
NACA TM 490、604、605、606、774、838
NACA TN 1197、1347、2661、2662
NASA CR 101854
AFFDL-TR-69-42
AFWAL-TR-85-3096
WADC-TR-89-3030
Airframe Stress Analysis and Sizing (CY NIU)

I'm not sure, As Crackman says, Vought Manual seems to be the source.

The 119p supplement to Bruhn is available on Archive.org

https://archive.org/details/BruhnSupplement/mode/2...

McCombs was also one of the authors of AFFDL-TR-67-184 Analytical Design Methods for Aircraft Structural Joints while at Vought.

Jim

Jim Kinney
Kennedy Space Center, FL

NACA TN 4053 has a discussion and some curves (check the NASA technical report server), I also remember seeing a hilarious paper that had the testing method of asking a bunch of people around the office at Lockheed if a panel looked "permanently buckled" but I can't remember the source, tbh the math was sane but the experimental method was... something. I think they just looked at extreme fiber stresses in the worst case locations for a buckled shape and compared to Fty.