Splice Plate Considering Moment & Axial Tension 1

[rsbmusicguy]

Hey guys,

I recently have been given the task to splice a new glue laminatrd beam to an existing glue laminated beam of the same section and properties for a building in order to accomodate a renovation.

Luckily, the location of the splice is an area where the moment is relatively small with respect to the remainder of the beam. However, in the past I have installed splice plate at inflection points and moment was never a major concern. I am trying to find resources online that provides a beam splice plate and bolt group problem considering both shear and moment.

So far I can see how as the beam deflects, this deflection will put the splice plate into tension and pull on the bolt group but I am having trouble calculating this axial/tensile force. Note I will locate my bolts at the neutral axis of the beam.

Any help is always appreciated!

RSB

 

[KootK]

I'd be inclined to model the splice location as a zero moment pin connection precisely because you'll detail it to resemble that. Then work out the member forces to be consistent with that assumption. Creating an end-to-end moment connection between glulam beams in such a manner that there's meaningful rotational restraint across the joint can be done but it's a tall order, both to design and to build. Flange plates, small diameter screws from Germany... fun & sexy, but expensive for you and whomever's slapping it together.

 

[dik]

??? Can you give me a hint?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik

 

[rsbmusicguy]

KootK,

Thank you for your input, I will definitely consider what yoou have said which makes sense.

RSB

 

[JoshPlumSE]

I agree with KootK about using a pin connection, and forcing the moment to be zero at that location. I don't care much for making wood framed moment connections.

KootK - why use screws from germany? Are you thinking the 1/4" SDS is too large of a diameter?

 

[jayrod12]

I think to an extent KootK was being facetious. It appears that all of the good fun research and supplier for cutting edge wood technologies are outside of North America, mostly Europe.

 

[KootK]

Yes to facetious.

 

[rsbmusicguy]

Out of curiousity - lets say my beam was steel and I wanted to provide welds at the splice connection instead (theoretically). If the weld at the splice connection is rigid than you can not analyze it as a hinge, correct?

 

[KootK]

If the weld at the splice connection is rigid than you can not analyze it as a hinge, correct?

In my experience, most engineers would assume the following:

1) If it's welded at the flanges, it can't be called a hinge.

2) If it's welded via shear plates at the web, with no welding at the flanges, it can be called a hinge.

 

[rsbmusicguy]

Got it - note for my splice plate I will not be providing any plates at the top and bottom of the beam.

RSB

 

[jayrod12]

Then definitely no moment transfer, or at least no appreciable moment transfer.

 

[r13]

What is the structural arrangement of the spliced beam, is it a member of a continuous frame, or one span frame/simply support beam? My question is whether a hinge is allowed under your framing arrangement.

 

[rsbmusicguy]

This beam is a two span continuous beam with an evenly distributed load over the full length, the hinge at the splice makes it determinate which is also nice

With the framing arrangement it should not be a problem since it is supporting the joists above and is independent of the column/supporting walls.

RSB

 

[r13]

It's fine. Check the deflection then.