Rigid end zone

[Saedhalteh]

Can someone help with an example of when to Include the Rigid end zone effect ?
I have searched about it and what I understand is it is a infinitely rigid zone which doesn't have deformations or have a negligible deformation, and an analysis based on center line to center line dimensions of such members may overestimate the actual deflections. But I cant find when we should include it or ignore it .

note : I am using RAMSS software

the second thing that I want to inquire about is when we should view member forces at the face of support and when to take the forces in the center line o supports ?

 

[271828]

Back in school, our matrix structural analysis professor said we should typically not be using rigid end zones unless we're accounting for panel zone shear and other sources of flexibility with a model such as Krawinkler or Scissors. We were taught that using centerline modeling without rigid end zones ends is typically the way to go.

 

[JoshPlumSE]

The NEHRP commentary has some good information about this. Essentially, for steel frames, you don't want to use rigid end offsets. That's because of the effect of panel zone deformation. In fact, there is some debate that center line modeling may not be sufficient to account for the extra flexibility caused by PZ deformation.

The only time I would do it is maybe if I had a side plate moment connection, since those are a lot more rigid in the panel zone area than other types of steel connections.

Steel moment connection design should be based on the forces at the face of the column. That's where the connection is.