AISC Punching Shear Rectangular Hollow Sections

[MegaStructures]

Does anybody by chance know how equation 9-29 from the 15th edition manual was derived? I’m trying to find the “source” research that we used to define this equation and haven’t had any luck.

The equation defines the punching shear strength of HSS-HSS connections. I have a connection that doesn’t fit the geometry (bird break connection) and want to figure out how the equation may be affected by the change. I think the shear perimeter will be reduced, because the failure will initiate at the stiffer corner of the bird beak

“The most successful people in life are the ones who ask questions. They’re always learning. They’re always growing. They’re always pushing.” Robert Kiyosaki

 

[271828]

I don't think there's any magic to it. It's 0.6Fy times the thickness times the perimeter of whatever is delivering the force, adjusted for the ceff thing of course.

I'd have to see a figure of your situation to be sure, but I'd probably compute the perimeter and sub it for the part in parentheses.

 

[MegaStructures]

Yea you’re right. I think what I’m looking for is how the Ceff term was derived. Like most empirical equations the constants in the equation seem fairly arbitrary and there are no references to the original research in the commentary.

My connection is a simple HSS-HSS T-connection with the chord rotated 45 degrees. I can draw a sketch when I’m near a computer later

“The most successful people in life are the ones who ask questions. They’re always learning. They’re always growing. They’re always pushing.” Robert Kiyosaki

 

[MegaStructures]

I think I’ve actually found it. On page 16.1-466 paragraph 1 “the effective width parameter has been derived from research on transverse plate to HSS connections (Davies and Packer, 1982)

Now let’s see if I can reasonably recreate their work to find effective perimeter for bird beak connections

“The most successful people in life are the ones who ask questions. They’re always learning. They’re always growing. They’re always pushing.” Robert Kiyosaki

 

[OldDawgNewTricks]

You might also look at other publications by Packer, et al:
- AISC Design Guide 24 Hollow Structural Section Connections
- the older AISC Hollow Structural Sections Connections Manual
- Hollow Structural Sections Connections and Trusses (free download from CISC)

 

[MegaStructures]

If anybody else has the same question there is some more good information here:

https://steeltubeinstitute.org/resources/hss-connections-with-rotated-members/

“The most successful people in life are the ones who ask questions. They’re always learning. They’re always growing. They’re always pushing.” Robert Kiyosaki