Welded Shear Connection Questions

[Buleeek]

Hello,

I have two questions:
1. When using AISC tables for welded shear connections, what is the load eccentricity assumed? I'm trying to solve a few examples in order to understand the welded connection design procedures.
2. Do you know where I can find some step-by-step weld connection designs? The AISC examples in almost every case use the already tabulated values from the Manual.

Thank you,

 

[ProgrammingPE]

1. The eccentricities for the AISC tables can be usually be determined from the drawings at the top of the tables. Sometimes you need to check the footnotes or the "Design Table Discussion" section that is on the pages before the tables to get some additional information. If you are wondering about a specific table, I can get you the actual values used since I validated all of those tables at one point.

2. The welds for the shear connections are designed differently depending on where they are located. Frequently, they use the "Instantaneous Center of Rotation Method" (ie. Double-Angle welds at beam). You can determine the capacities by getting the Weld Group Coefficient using AISC's Tables 8-4 to 8-11. In case you want to know how AISC determined those values, I've attached an example calculation that shows that for Table 8-8, a = 1.0, k = 0.5 results in a C value of 1.67. Other welds are designed using elastic methods (ie. Double-Angle welds at support), so there's equations for them where you can determine the capacities directly.

Let me know specifically which weld capacity you are trying to determine, and I can get you more information.

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