For flanges not restrained against rotation

[Prestressed Guy]

I am trying to size web stiffeners on a heavy rolled section (W27x368) and do not find any guidance. Any suggestions where to look? The members are a pair of cantilevered posts taking a large horizontal force. Mu = 4700k-ft Vu = 1880K

 

[WinelandV]

AISC Design Guide 13: Column Stiffeners is a good first place to look.

Otherwise, section J10 in the AISC 360 states

When the required strength exceeds the available strength as determined for the limit states listed in this section, stiffeners and/or doublers shall be provided and shall be sized for the difference between the required strength and the available strength for the applicable limit state. Stiffeners shall also meet the design requirements in Section J10.8.

Please note that I am quoting from the AISC 360-05. The most current spec is the AISC 360-16, but that one is sitting on my desk at home.

Please note that is a "v" (as in Violin) not a "y".

 

[dold]

Alex T. / Joel Berg have spreadsheets for stiffener design: STIFFENER.xls and STIFFENER13.xls

[URL unfurl="true"]https://www.steeltools.org/beam.php[/url] towards the bottom of that page

 

[Prestressed Guy]

Design guide 13 relates to Wide-Flange Column Stiffening at Moment Connections. This is not a moment connection. It is more like a two post road sign. The loads are straight line horizontal with no torsion into the posts.

 

[WinelandV]

The reason why I pointed you there was because frequently for moment connections, you end up with large flange forces that the column can not handle on its own pushing you to either upsize the column or add stiffeners. It does also include the calculations for the stiffener design, including welds. It may not be exactly the same, but it should get you going in the right direction.

Please note that is a "v" (as in Violin) not a "y".

 

[Prestressed Guy]

I have a copy of that deisgn guide somewhere in my library but cannot find it currently. Is it available online for a non-AISC member?

 

[WinelandV]

DG13 does not appear to be available for free to non-members. I don't suppose you have a copy of Steel Structures: Design and Behavior by Salmon and Johnson somewhere around your office?

Please note that is a "v" (as in Violin) not a "y".

 

[Prestressed Guy]

I do actually. 2nd edition Copyright 1980. It was gifted to me in 2000 because it was sooooo old. I don't do steel unless it is related to prestressed concrete and the production thereof.

 

[driftLimiter]

This is a bearing stiffener, AISC Section J10 Applies. Section J10.8 provides a method to size the stiffener properly.

 

[Prestressed Guy]

(Structural)27 Jul 22 19:45
Alex T. / Joel Berg have spreadsheets for stiffener design: STIFFENER.xls and STIFFENER13.xls

https://www.steeltools.org/beam.php

towards the bottom of that page

The web on these things is 1.38" thick and at the max shear locations I need to add a 1" web doubler to get the shear capacity needed so the h/t ratio is very low So they may not need any transverse stiffeners which from a fabrication standpoint would be very nice. It just makes me nervous.

In working through the stiffener spreadsheet, it does not appear to have the ability to change the section properties of the section form wb from 1.38" to 2.38" so it is not happy with my inputs.