Haunched connection 1

[LeonhardEuler]

I'm analyzing a structure that holds an over-head crane and am having trouble finding the correct method to analyze the "haunched" connections that connects at the column line and supports the runway beam. My first thought is to simply analyze the 3/4" plate for buckling as it should be the limiting piece, but I know the I-beam will surely add strength in composite action. Attached is a drawing of the connection.

 

[hokie66]

Not sure which country you are in, but you should be using the appropriate crane code to assess this runway, including the building frame, the runway beam, bracing, etc. I have worked a lot in industrial structures, and have never seen a 60 or 65 ton crane runway supported by brackets.

 

[hokie66]

This design guide by R A MacCrimmon is an excellent source for design of crane runways.

https://www.amazon.ca/Crane-Supporting-Steel-Structures-Design-Guide/dp/0888112084

 

[LeonhardEuler]

I'm in the US I used AISC design guide 7 to analyze the runway beams.

 

[LeonhardEuler]

Does anybody have an idea on how to deal with the torsion on the triangular bracket in this case?

 

[KootK]

Were talking about torsion one the column, right? I'd expect that to manifest itself primarily as strong axis flexure in the uppermost flange element. Hopefullly there's a stiffener behind that.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[LeonhardEuler]

I was actually talking about the force on the bracket plate from the longitudinal crane force. The more I look at it though since it's being modeled as a column according to salmon and johnson textbook and vinakotas guide then the longitudinal force would be transferred as a bending force at the end of the "column" and I could use the interaction equation H1-1b from AISC. I've always wondered why there isn't a similar equation that includes torsion and shear stresses.

 

[KootK]

I was actually talking about the force on the bracket plate from the longitudinal crane force.

Right. That longitudinal force will manifest itself as column torsion but bracket weak axis bending and shear. And bracket weak axis bending and shear will effectively be strong axis bending of the uppermost flange element. I'd look at that flange as being subject to an in plane tension and an in plane moment/shear. I think that's similar to your proposal. It's just important to recognize that the entire section is unlikely to participate in resisting the longitudinal force meaningfully.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.