Connection Stiffness/Rotation 2

[PEinVA]

Does anyone know any good articles that provide information about expected stiffness/rotation of steel connections? I'm not looking for partially restrained documents, but simply supported non-composite beams and how the connections affect the deflection characteristics of the beams.

I have searched AISC Journals and Conference epubs, and cannot find anything.

Thanks for help in advance!

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[ash060]

Try "Moment Rotation Characteristics of Shear Connections" by Kennedy in the AISC Journal. It is an old article (1969 I think) so it may not be on the AISC website.

It has some equations and graphs of what you are looking for. The tests were done with end plate connections but I think that the information can be applied to other shear connections.

Also, you can look for some articles by Chen & Kishi.

I hope this helps.

 

[271828]

You'll need to search for experimental programs on specific types of connections. The researcher will often show M-theta curves.

For example, Fig. 8 of the following paper shows the recorded curves for some single angles. I've seen curves for shear tabs also and I'm sure papers like this exist for other types.

Gong, Y., "Single-angle all-bolted shear connections," Journal of Constructional Steel Research, Dec. 2008.

 

[UcfSE]

Do you have a particular problem you are trying to solve with this information?

 

[PEinVA]

Not really a problem, but just for future knowledge with regard to camber.

We've only used 70% of anticipated DL for camber in the past and it hasn't been an issue, but we wanted to be able to review connection stiffness for future projects.

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[miecz]

The Guide to Design Criteria for Bolted and Riveted Joints references two studies of flexible joints;

W.H.Munse, W.G. Bell and E. Chesson, Jr. "Behavior of Riveted and Bolted Beam to Column Connections," Journal of the Structural Division, ASCE, Vol. 85, ST3 March 1959.

C. W. Lewitt, E. Chesson, Jr., and W. H. Munse, Restraint Characteristics of Flexible Riveted and Bolted Beam to Column Connections, Engineering Experiment Station Bullien 500, Univ. of Illinois, Urbana, 1969.

The guide says the rotation is dominated by the flexibility of the angles, and that, for tested connections, the restraint is around 10% of the fixed end moment provided by rigid moment resistant connections.

 

[271828]

I think it's well established that 85% of the precomposite dead load deflection is a very good amount of camber.

We actually measured camber on a couple of jobs and were amazed at how accurate it was. I had been under the impression that it was very unreliable. Of the 6-8 beams we measured, I don't think one was off by more than 1/16" from the camber that we indicated. They were almost completely flat with teh concrete on there. People get very worked up over over-cambering, but I'm inclined to think that it is completely unjustified and fueled by lack of data.

 

[PEinVA]

271828,
You didn't see any difference for a beam connected by a single angle at another girder and a beam connected by double angles at a column flange?

Thanks.


RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[271828]

No, but I admit that the experiments were brief and do not represent a thorough treatment of the subject. For all I know, all of the connections were the same kind. I do remember that I had them check beam-to-girder and beam-to-column flange connections, though. We cambered out 85% of the precomposite deflection and that seemed to work great.

 

[PEinVA]

Thanks for the input.

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[PEinVA]

Ok, so I started looking at some PR information to get the M/theta curves.

I have the Richard-Abbott equation and I am having trouble putting this equation into excel and I can't get it to match the provided example.

Anyone use this formula?

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke