Trolley Crane Extension

[RedN]

My boss has asked me to design a 6ft (cantilevered) extension onto an overhead crane trolley. The beam is a continuous beam, underslung from the roof supports. I intend to butt weld an extension to the end of the beam; however, I am a bit confused on how to analyze the connection points. In four places, it has four bolts through the top flange in a square pattern, spaced approximately 3 inches apart on either side. Would this connection be considered a rigid connection? If it is considered rigid, how do I make sure that I am not overstressing the bolts. Should the bolts be considered a couple moment to withstand the addition moments added to the end?

I apologize if this all seems trivial as this is my first steel design project. I am trying to assess whether or not additional supporting structure is required for this setup. My intuition says yes, but I am trying to justify it. The crane is a 2 ton hand trolley.

Thanks in advance.

 

[paddingtongreen]

What is the beam bolted to? is it stiff or flexible. Beam size? The Devil is in the details. What is the spacing between the existing supports? Will you be able to laterally stabilize the cantilever end.

I think you will get different opinions as to the interpretation of the connections.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[hokie66]

The connection to the overhead support is just a tension connection. Consider it as a pin or roller in your analysis.

 

[paddingtongreen]

LOL. hokie, Up until a couple of years before I retired, I would have posted the same as you but I had to look at a misbehaving trolley beam. It was bolted hard to a very stiff structure that refused to rotate in any significant amount. The bolts were overloaded by the leverage, akin to prying action.
Funny thing though, my job was to find out the source of the trouble, and when I offered to add designing a fix to the purchase order, they decided to handle it themselves.

Michael.
Timing has a lot to do with the outcome of a rain dance.