steel and RC moment resisting frame damping

[Horr]

Hi,

In most opensees examples the xDamp (damping ratio) is assumed 0.02 for both steel and RC moment resisting frames. I thought 0.05 is the typical damping among engineers. I wish to know the damping ratio for different structural systems, i.e. steel MRF, RC MRF, wall-frame and braced frame.

Can anyone help me by some engineering judgement or by some research papers?

[Horr]

No idea!

[andreascj]

See Chopra's book on structural dynamics.

[vesna]

I suggest you to also read papers given under notes here: http://opensees.berkeley.edu/wiki/index ... ng_Command

[Horr]

Great day to all,

I have classic moment frames with elastic beam and column element and concentated plasticity at both element ends represented by rotational spring. I want to set the moment-rotation relationship in such a way to be proper for the strength and stiffness degradation (or pinching) of RC frames.

It seems the hysteretic material is the best. Am I right?
Questions:
1. what is the Reference (theoritical or experimental model) for the presented hysteretic model?
2. can it simulate only the strength degradation without stiffness degradation (It seems peak-oriented)?
3. How can I set the parameters as the Reference below:
http://dx.doi.org/10.1080/13632460902859144

Thanks,
Horr