Shear Flow - End Weld Requirement

[JNEnginr]

Hello, I'm reinforcing a Steel Beam with a WT section. I've done the shear flow calc to determine the shear flow in kips/in. I know i can do a quick weld calc to determine the thickness of weld i need to resist said shear flow. My question is, does this weld have to extend the entire length of the beam? I've heard of providing a weld at each the end of the beam to suck up the shear, but what is the calc method? Thanks for your time and help. (For explanation purposes, lets say V = 58k, span of beam is 24ft, Ix = 4889in^4, Q = 249in^3, therefore, q=2.95k/in)

 

[ToadJones]

Many use MQ/I at the ends...it equates to a force.
I believe you use "M" as the full elastic capacity of the built up beam....FySx.
I don't have my references on me here....i know it is covered in the Green ASD book and I believe in Blodgett

You should remove this post and re-post in the "structural engineering other tech topics" forum

 

[ToadJones]

What I posted doesn't make sense now that I re-read it.

"M" should probably be the moment at the point where the reinforcing is no longer needed.

To be conservative, you can probably just use (0.6Fy x the area of the reinforcing) as the force you need to develop with the end welds.
This is covered on pg 5-132 of the old Green ASD book.

 

[JNEnginr]

Thanks.