Strength of 3/4" Mild Steel Nelson Stud Welded to 5x5x1/2" A500 Gr B Square Tube

[strainstress]

Hi:

I am trying to figure out whether a 3/4" nelson stud is sufficient to mount a fan on top of 5x5x1/2" Square tube. The nelson stud will be subjected to both tension and shear due to seismic load on the fan.

How do I calculate the allowable tensile and shear load on the stud? And what is the interaction equation between tension and shear components? I know how to do it for a regular A325 bolt, but am not sure how do the same for a stud

Thanks

StrainStress

 

[wannabeSE]

I am not certain how you plan to use the stud. They are typically embedded in concrete. ACI 318 appendix D is used to calculate the capacity when used as a concrete anchor. The shear capacity is in the Steel Construction Manual when it is used for composite construction. And, welding requirements in AWS D1.1, here are some other resources:

1977 Nelson Stud Design Manual can be downloaded from Sliderule Era's website:

http://www.slideruleera.net/contributions.html

An ICC ESR also provides some information:

http://www.icc-es.org/Reports/pdf_files/ESR-2856.pdf

 

[strainstress]

@ wannabeSE : Thanks for your response.

I am planning to use AWS D1.1 Type A general purpose stud (

http://www.nelsonstud.com/pdf/pci.pdf),

stud welded directly to the tube. The fan will then be installed using these studs and washers/nuts. Is this not an acceptable approach to mount an equipment ?

Also, in order to develop full strength of a stud, is there a min. yield/tensile strength requirement of base material ?

Thanks

 

[msquared48]

Oh, you mean a Nelson Sill Plate Anchor, not a Nelson Stud...

The sill plate anchor is just a piece of threaded rod, whereas the stud has a head on it.

Mike McCann
MMC Engineering

 

[wannabeSE]

I am guessing that you plan to use a fully threaded stud. Nelson stud manufactures a plethora of studs in several different materials:

http://www.nelsonstud.com/Portal/Products/Fasteners/Catalog/tabid/58/Default.aspx.

I think you need to download the entire catalog to get the section that lists the material properties.

I have only used Nelson Stud embedded in concrete (deformed bar anchors, concrete anchors/headed studs and shear connectors). I suggest you call Nelson Stud for the best answer. I assume you would need to check the stud similar to a A325 bolt except using the stud's tensile strength. If it is heavily loaded, the base metal may need to be checked for rupture and yielding. Chapter K of AISC 360 (

http://www.aisc.org/content.aspx?id=2884

) may provide some insight on checking the tube steel. When the stud is shot on with a stud welding gun, the weld strength typically will not govern. See AWS D1.1 for minimum base metal thickness. But again, I have never used Nelson Studs in this manner. So, I am just throwing out some ideas.