using a weld size more than the web thickness. 2

[malikasal]

Hey Guys,

When designing a BCW shear plate connections, AISC 14th edition part 10-101 uses a minimum limit of the weld size to be 5/8 tp .

Due to using an extended configuration for the shear tab to ease the erection process, the required plate thickness is sometimes quite thick, causing the 5/8 tb limit larger than the column web thickness, is that a problem?.






ôIf you don't build your dream someone will hire you to help build theirs.ö

Tony A. Gaskins Jr.

 

[KootK]

I don't see it as a problem if you're doing the extended shear tab thing. What you want from the weld is for it not to rupture ahead of tab flexural yielding. In this situation, 5/8t may well be extraneous as the column web might develop a yield line mechanism causing it to stop resisting additional moment at the weld joint before the plate yields in flexure. Knowing exactly when such a yield line mechanism kicks in is not a simple matter of course. So stick with the 5/8t for the sake of simplicity and conservatism.

 

[Ron]

Depending on your configuration and load path, a weld thickness greater than the material thickness would be considered reinforcement of the weld which is not allowed by some codes, so you can only consider weld thickness up to the material thickness in your analysis.

 

[malikasal]

guys,

here is what AISC solutions think about this:

Malik,



I do not believe there is anything that would prohibit what you have described below (fillet weld sizes larger than the column web thickness). I also don’t necessarily see a problem with this either. We cannot make design decisions so you will have to use your own judgment when determining if the connection to the column web is adequate. The 5/8tp recommended weld size helps to ensure that the connection can meet the requirements in Section B3.4a of the 2016 AISC Specification and provide sufficient rotation capacity.



You can find more guidance on this from the EJ papers referenced below (a free download at

http://www.aisc.org/ej).

Muir, L.S. and Hewitt, C.M. (2009), “Design of Unstiffened Extended Single-Plate Shear Connections,” Engineering Journal, AISC, Vol. 46, No. 2, pp. 67–79.



Muir, L.S. and Thornton, W.A. (2011), “The Development of a New Design Procedure for Conventional Single-Plate Shear Connections,” Engineering Journal, AISC, Vol. 48, No. 2, pp. 141–152.



Please let me know if you have any additional questions.



Sincerely,

Carlo Lini, P.E., LEED AP BD+C
Staff Engineer
American Institute of Steel Construction
866.ASK.AISC



ôIf you don't build your dream someone will hire you to help build theirs.ö

Tony A. Gaskins Jr.