Re: Welded Shear Connectors

I would agree Doug. The only exception may be if you're using that as the tension wall anchor as well, but I wouldn't think so.

In non-composite beam applications, you can use the Ultimate values of the shear studs with Omega forces and DSA will be okay with that. I've done that several times.

-gm

On Thu, Aug 6, 2009 at 12:04 PM, Doug Mayer <doug.mayer@taylorteter.com> wrote:

Thanks for the reply, Gerard.  Reading the section, it seemed that they were focused on diaphragm force transfer in conjunction with composite action.  But the way it is worded seems to imply that use of welded shear studs in ANY application other than composite construction would take this hit.  It sounds like this section would not apply to an embed plate with welded studs into a tilt wall used to support a non-composite steel beam…would you agree?

 

Thanks,

 

Doug Mayer, SE

Structural Engineer

 

From: Gerard Madden, SE [mailto:gmse4603@gmail.com]
Sent: Thursday, August 06, 2009 11:35 AM
To: seaint@seaint.org
Subject: Re: Welded Shear Connectors

 

This one is a pain.

Basically their opinion has to due with the shear studs being used to take diaphragm shears into the collectors, they consider that to be the function of the shear stud. They will say it cannot simultaneously act to deliver the composite shear from dead & live loads and lateral force.

Using the exception is basically the same thing (divide by 2.5 or 3 for omega)

What we do is design the collectors and beams under this loading condition as non-composite and use the shear studs only for lateral shear out of the concrete filled metal deck. DSA has no problem with this approach.

-gm

On Thu, Aug 6, 2009 at 10:48 AM, Doug Mayer <doug.mayer@taylorteter.com> wrote:

There is a provision in the DSA/OSHPD section of the 2007 CBC (2204A.1.2) regarding the design and capacity of welded shear connectors.  In this section, it states: "When welded shear connectors are used for applications other than composite construction, such as for transfer of shear loads to ledgers, collectors and diaphragm chord members, the allowable shear strength or design shear strength, as appropriate, shall be one-third of the available strength."  It then gives an exception to this reduction as long as you use overstrength factors on your design load. 

 

Any ideas why they penalize welded shear connectors like this?  I'm assuming it has something to do with the behavior/ductility of the weld as opposed to an anchor bolt.  Any thoughts would be appreciated.

 

TIA,

 

Doug Mayer, SE

Structural Engineer