Damping in Response Spectrum Analysis
Damping in Response Spectrum Analysis
(OP)
Dear Sirs,
we want to know how the response-spectrum curve will automatically be adjusted from the function damping value to the actual damping present in the model.
We just found an answer (see below), but our simplified calculations (S-DOF System) show a different behaviour.
Please clarify ! (FYI: we are using SAP2000 version 14.2.2)
Thank you very much
https:/ /wiki.csib erkeley.co m/display/ kb/Damping +in+respon se+spectru m+analysis
A2 = A1 * (2.31 - 0.41 * log(D2)) / (2.31 - 0.41 * log(D1))
where:
* A1 = acceleration corresponding to damping ratio D1,
* A2 = acceleration corresponding to damping ratio D2,
* 0.0 < D1 < 1.0,
* 0.0 < D2 < 1.0,
* and log = natural log (base e).
we want to know how the response-spectrum curve will automatically be adjusted from the function damping value to the actual damping present in the model.
We just found an answer (see below), but our simplified calculations (S-DOF System) show a different behaviour.
Please clarify ! (FYI: we are using SAP2000 version 14.2.2)
Thank you very much
https:/
A2 = A1 * (2.31 - 0.41 * log(D2)) / (2.31 - 0.41 * log(D1))
where:
* A1 = acceleration corresponding to damping ratio D1,
* A2 = acceleration corresponding to damping ratio D2,
* 0.0 < D1 < 1.0,
* 0.0 < D2 < 1.0,
* and log = natural log (base e).





RE: Damping in Response Spectrum Analysis
The wiki-Page was also corrected.
Note: The damping ratio has to be entered like this:
5% = 5.0 (and not 0.05)