Connecting Wide flange beam to a Beam reinforced with WT section at bottom 1

[anchorengineer]

Hi All,
I'm looking for a relatively clean way to connect a wide flange beam to an existing beam reinforced with a WT section at the bottom. The extra challenge is that the connecting beam is lower than the the reinforced beam. Please take a look at the attached sketch. I hate to cope too much of the web of the attaching beam and I'm concerned about construct-ability/weld-ability. I'd appreciate any thoughts or feedback.
Thanks!

 

[DrZoidberWoop]

Maybe something like this. Slot the connection plate around the flange(s) and weld the full depth of the shear connection plate. Add another plate as required.

 

[KootK]

My entry below.

- I tried to avoid cross flange welding on the existing beam.

- Give some consideration to connection rotational ductility. A stiff supported beam helps as does torsional flexibility in the supporting girder.

- Maybe throw in some erection bolts.

Dr Z. always wins these things but everyone ought to have some competition.

 

[EngDM]

As an addition to DrZoidberWoop, I'd be adding a stiffener to the other side of the beam as well, and checking how much torque is generated at the ends of the beams due to this large eccentricity from the connection itself. The existing connection may be torque sensitive, especially if it is just a shear tab.

 

[anchorengineer]

All,
Thanks for your input. As I drew the detail in ACAD i realized that the attaching beam almost fits completely on the WT. I will used long legged angles to connect to the web of the WT and fill in any gaps above with a plate to cross the high stress locations. I also added the stiffener plate to the back side of the WT.

 

[KootK]

As an addition to DrZoidberWoop, I'd be adding a stiffener to the other side of the beam as well

I also added the stiffener plate to the back side of the WT.

Why do you guys favor the back side stiffener? I don't really see the benefit of it other than as a generic "more is better" approach.

When it comes to welding to existing beam flanges, I feel that less is better.

 

[icebloom]

Another connection you can try is a hanging endplate connection or some variant of this.

Variants of this connection would involve either adding gusset above the new beam, or below your WT section to get additional connectivity to the endplate. If highly loaded you tend to get a bit of shear lag with these kind of connections and the bottom stiffener/weld will take more force so the additional plates mentioned above can help spread the load out. Probably has the smallest local eccentricity in the connection too from bolts to web of supporting beam so minimum bending going through the connection which is desirable. You don't have to cope anything either.

 

[cliff234]

My suggested detail is similar to Koot’s. Design the plate and bolt group for an eccentricity = “e”. Design the plate weld to the beam web for a vertical reaction “V”. Add additional columns of bolts if required. Check the plate for moment, shear, and buckling.