Eccentricity in Column W12X72 to Beam W33X118 Shear Plate Connection with Stiffeners
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Question

Eccentricity in Column W12X72 to Beam W33X118 Shear Plate Connection with Stiffeners

Veer007 (Civil/Environmental)

(OP)

26 Sep 24 16:34

Hello everyone,

I’ve come across a question while designing a w-column web-to-beam shear connection, and I couldn’t find a specific reference in the AISC handbook to clarify this. I’d really appreciate any insights.
Context:
• Column: W12X72
• Beam: W33X118
• Connection: Extended shear plate with stiffeners at the top and bottom
• I used two rows of 9 A490 bolts (1" diameter) based on connection design software for the shear connection.
In a moment connection, I understand that we weld the top and bottom flanges, and the web is connected with bolts. However, this case is a shear connection, and my question is about the eccentricity.
Questions:
1. For the shear connection, should I consider the eccentricity from the column web to the bolt group center or from the flange/stiffener edge? I assume the stiffeners may reduce the eccentricity, but I couldn’t confirm this from the AISC handbook.
2. For a moment connection where the beam flange is welded, how should the eccentricity be considered? Should it be from the stiffener/column flange edge or column center?

Thank you in advance for your help!

Thanks in advance!!

Deker (Structural) · Answer 1 · 2024-09-26 16:56:57

This article discusses shear connection design when stabilizer plates are used: Link. The bolt group can be designed with a reduced eccentricity if the stabilizer plates are sized accordingly.

JoshPlumSE (Structural) · Answer 2 · 2024-09-26 17:17:56

Quote:
2. For a moment connection where the beam flange is welded, how should the eccentricity be considered? Should it be from the stiffener/column flange edge or column center?

Huh? This part of your question almost answers itself.

Your analysis should have already consider the moment imparted from the bream into the column. So long as that is done properly, there is no need to consider additional eccentricity. There are some caveats for Special Moment Frames using in high seismic regions.

Veer007 (Civil/Environmental) · Answer 3 · 2024-09-27 13:25:09

So I can eliminate eccentricity if the stabilizer is designed to accommodate the shear force, right?

Thanks in advance!!

dik (Structural) · Answer 4 · 2024-09-27 14:45:56

What is your connection force?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

Veer007 (Civil/Environmental) · Answer 5 · 2024-09-28 08:22:23

V=130k for this one, but I also have the same doubt in moment-connection for where to calculate eccentricity.

Thanks in advance!!

271828 (Structural) · Answer 6 · 2024-09-29 15:35:08

In a moment connection, the shear connection can be designed for zero eccentricity. From the 16th ed. AISC Manual Page 11-4:

"Shear is transferred through the beam-web shear connection. Since, by definition, the angle between the beam and column in an FR moment connection remains unchanged under loading, eccentricity can be neglected entirely in the shear connection."

dik (Structural) · Answer 7 · 2024-09-29 15:58:23

Do you need a double row of bolts? Can they be ASTM F3125 Gr A325? and can they be 3/4" dia?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

Veer007 (Civil/Environmental) · Answer 8 · 2024-10-02 16:42:29

Quote (271828)
Thanks for the response, we can eliminate eccentricity in FR moment connection, for shear connection?

Thanks in advance!!

Veer007 (Civil/Environmental) · Answer 9 · 2024-10-02 16:45:34

Quote (dik)
I rely on software to design this connection since I am a detailer, I just provided the connection based on the report it gave me, all questions you mentioned above are my doubts as well

Thanks in advance!!

dik (Structural) · Answer 10 · 2024-10-02 16:54:19

OK, thanks for the clarification.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

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Eccentricity in Column W12X72 to Beam W33X118 Shear Plate Connection with Stiffeners
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