Wooden beam scarf design 1

[mar2805]

Hi!
Does anyone maybe have an solved egsample of how to design a wooden beam splice?
Ive modeled an situation of 2 bay wooden beam that needs to be connected with another beam.
Picture attached.

Joint is positioned at zero bending moment position so the joint is only loaded with vertical force.
Conection using metal bolts.

Thank you.

 

[jayrod12]

What does the rest of the structure look like, i.e. how far away from the support does the splice happen, what are the two span lengths, beam size, etc.

I honestly see this situation more as a cantilever beam and a drop-in beam. Looking at it this way you have to check one beam as simple span, the other as cantilevered. and then check the cantilevered beam for shear at the bearing point of the simple span beam (the reduced cross section area).

If the shear of the cantilevered beam at the reduced cross section is fine, and is also fine for negative moment at the support, then the bolts are just there to keep the beams in place and wouldn't do a whole lot from a loading perspective. Although with the slope bearing you are showing there will be an induced axial force so they would need to be sized for that shear.

Personally, I'd prefer a butt-splice with a steel knife plate for an aesthetically pleasing strictly shear connection. Reducing the cross section of wood beams still doesn't sit right with me. If it needs to be notched then I prefer square cuts as opposed to the sloped one you've shown.

 

[mar2805]

Hi jayrod.
Please see picture attached for more information.
The joint (lap) is located at zero bending moment location.
Shear force is NOT zero at this location.

Bending stresses checks at internal support are OK
Shear stresses at internal support are OK
Bending stresses ar first bay span are OK.

 

[lsmfse]

hi Jayrod,

I thought this might be of interest to you.