Assigning Damping to a Complex Frame

[Samira M.]

Dear Dr. Silvia
I'm working on RC frames modeled with [b]beamWithHinges for the Beam elements[/b] and [b]dispBeamColumn with fiber section for the Column elements[/b] (the interaction between Axial and Moment is important for column's behavior in my research, so fiber section is selected).
the frame models also include interaction with soil-foundation interface. the material which is used for the soil has the capability of defining a specific damping which is assigned directly to the elastic portion of the material behavior (Qzsimple1).

[b]the question is: how can I assign the appropriate damping to this system?[/b]

(as I know, I should assign damping to the elastic portions of the elements. the soil material makes no problem in this regard. but what should I do for the beams and columns?)

Thank you in advance
Regards

[yalham]

check PEER report 2007/12.

[Samira M.]

Thank you yalham
I checked the report, it has mentioned the way the damping is assigned (which is according to Medina (2002), assigning the damping to the elastic elements).
But I still have the problem. cause I don't have access to Elastic portions of the beam and column elements. as I have described before, the elements are beamWithHinges and dispBeamColumn.

what I should I do in this case??

[yalham]

I introduced that report because of notes on the effect of SSI on damping. Modeling of damping is my problem too, but in CBFs, however, currently I can’t search for it.
Here there are several useful references:

Bernal 1994, ASCE Journal of Structural Eng.

Medina, PEER 2003/15

Hall 2006, Journal of E.Q. & Stru. Dynamic, Wiley-InterScience

Zareian, Blume Center-Stanford, report No. 169

But I think the best way is to check it with “Farzin Zareian”, faculty of UC-Irvin, at least to find out that which of the above references are the best, and/or related techniques of modeling.

[silvia]

you can define regions and then assign damping to those regions alone.