Effect of column forces in designing column-beam connection
Effect of column forces in designing column-beam connection
(OP)
As structural engineers, we normally provide the connection forces (moment, shear and axial forces) from a beam for MC connection between a column and a beam. The forces from the column (moment, shear and axial) are not provided. However, as per AISC design guideline 13, the column shear will affect the panel zone shear capacity. I have not found an example which includes column forces (shear, moment and axial) in designing MC connection between column and beam.
My questions are:
1.Should column forces be included in the column and beams connection design? Is there anyone who has such experience or knows any reference?
2. What will steel detailer do if no column forces are provided? Will he assume some value for column shear in design the connection?
3. If column forces are provided, what will detailers do with combination of forces from column and beams?
Any comments and suggestion will help me a lot. Thanks.
My questions are:
1.Should column forces be included in the column and beams connection design? Is there anyone who has such experience or knows any reference?
2. What will steel detailer do if no column forces are provided? Will he assume some value for column shear in design the connection?
3. If column forces are provided, what will detailers do with combination of forces from column and beams?
Any comments and suggestion will help me a lot. Thanks.






RE: Effect of column forces in designing column-beam connection
The problem with trying to transmit complex loadings is that there are several cases to cover. Designing the connections provides another layer of thought about the fitness of the members, it often becomes clear that a different member would make the connection design so much better.
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Effect of column forces in designing column-beam connection
When you design major connection and check panel shear, do you consider the shear and tension from column? Have you see any calculation include shear from column?
Thank you very much for help.
RE: Effect of column forces in designing column-beam connection
Sorry don't mean to be harsh.
RE: Effect of column forces in designing column-beam connection
You need to look in the AISC code of standard practice, it requires that all the forces necessary to complete the design of the connection are shown on the drawings.
Typically, I will spec the stiffener and doubler plates at my columns if they are needed. The detailer will not check if these are required, because he is just designing the connection not the actually members. During your design you make pick a heavier column just to avoid having to provide stiffeners or doublers. The column shear, moment, and axial forces are the engineer's to design for.
The code of Standard Practice only allows for the design of Connections. The definition in the code for connections makes me think that doubler plates and stiffeners are not connections because they do not actually transfer the forces between the members. They just reinforce a section.
RE: Effect of column forces in designing column-beam connection
RE: Effect of column forces in designing column-beam connection
RE: Effect of column forces in designing column-beam connection
Newlearner, I'm not sure what the common practice is in the US/Canada but why don't you design and detail all the connections? I'm based in Australia and here the structural engineer is responsible for all connections. Even if the shop detailer does a connection we don't show, we still have to review and approve it or we (not the detailer) will face litigation if something every goes wrong.
RE: Effect of column forces in designing column-beam connection
http://www.aisc.org/content.aspx?id=2884
RE: Effect of column forces in designing column-beam connection
newlearner, is asking a valid question. almost all end plate moment connection excel spreadsheet i see dont have "cells" to input column forces.
i'm not sure about descon software. i have not used it for sometime.
RE: Effect of column forces in designing column-beam connection
I'm still curious though as to why you don't specify the connections yourself?
RE: Effect of column forces in designing column-beam connection
RE: Effect of column forces in designing column-beam connection
In America it is common for a specialist connection engineers to design the connection on behalf of the fabrication company. Connectegr from http://www.FerrellEngineering.com is one such person, he may drop byand give a full rundown. This hasn't caught on in Australia yet, With most engineers having to both the design for the structure and connections.
A clear conscience is usually the sign of a bad memory
RE: Effect of column forces in designing column-beam connection
RE: Effect of column forces in designing column-beam connection
The way to really answer this question is to sit down with a senior engineer, in-house or external, and have a discussion about LOAD PATH at a beam-column moment connection.
Then you'll understand why some "spreadsheets do not contain these values"...
tg