Whitmore Section and Gusset

[anewbieengineer]

Hi All, I have a question regarding a connection for a HSS brace with tension and compression that is welded to a gusset plate. I understand that the Whitmore Section start at the intersection of the HSS to the gusset and project 30 degree out to the end of the HSS. If this is for conventional construction and 2-t distance for ductility is not required,should the brace be positioned far out enough so that the whitmore section clears the adjacet members? It might be easier to refer to my sketch attached to visualize my question. Thanks.

 

[connectegr]

The whitmore represents a maximum, and is not required in the consideration of the gusset dimensions.

http://www.FerrellEngineering.com

 

[JAE]

Good article on it -

http://www.modernsteel.com/Uploads/Issues/July_2011/072011_July11_Steelwise_web.pdf

It shows various examples and discussions that might apply to your question. I think connectegr is correct and your B sketch is similar to those in the linked article.

 

[slickdeals]

@connectegr : I had sent you an email. Hope it did not end up in spam.

It’s no trick to get the answers when you have all the data. The trick is to get the answers when you only have half the data and half that is wrong and you don’t know which half - LORD KELVIN

 

[anewbieengineer]

Thanks for all the replies. Thanks JAE for the reference, it is very helpful. However, I think it only explains how the Whitmore is used for determining gusset yielding and buckling, but it didn't address whether the welds can be considered effective in transfering the load to the connected supporting member if it is outside of the whitmore. What I was thinking is, if load follows the geometry of the whitmore to propagate within the gusset, then wouldn't it make sense that the portion of the gusset edge outside of the whitmore is not effective in transfering the load into the support member, since that area will not be consider when considering yield strength and buckling column width anyways?

 

[WillisV]

Yes, the welds outside of the Whitmore may be considered for transferring the load to the connected supporting member. It is done all of the time. The stress in the welds is obviously going to vary and have "hot spots", which is why the weld is designed for the max of the peak stress or the average stress calculated across the weld line increased by the Richard's Factor (used to be 1.4, but now 1.25) to help account for these stress risers and allow redistribution.

For an example of this see

http://www.aisc.org/designexamples

and look in the 14th Ed. examples, example II.C-2 (p600 of the actual PDF). The weld to the top beam is well outside of the whitmore. The full length of this weld is used, and the stress is increased by the Richard's Factor as shown on p620-621.