How to model the non-classical damping in OpenSees?

[EmadOgail]

I am modeling a structure equipped with a tuned mass damper.
For this purpose, the non-classical damping matrix should be used to get accurate results.
Please, can anyone show me how to model this type of damping instead of Rayleigh damping or modal damping?
Thanks

[mhscott]

You can model the TMD directly using springs and dashpots: https://portwooddigital.com/2023/11/11/ ... er-models/

[EmadOgail]

Thanks for your response professor,

I know how to model the tuned mass dampers in OpenSees but I am asking about the damping of the main structure in the case of using TMD.

I want to model the complete damping matrix (non-classical) in OpenSees instead of classical Rayleigh or modal damping to give accurate results.

The following link is for a paper that mentioned that they modeled the non-classical damping is modeled in OpenSees but no details were provided.
https://doi.org/10.1002/eqe.3526

Here is a quotation for what I mean:
"Rayleigh damping is applied to the first two modes of the uncontrolled structures with 2% damping ratios for idealization of structural damping in order to construct classical damping matrix for the structure without TMD in the time history analyses. Then by modeling TMD parameters and assembling its damping coefficient into the aforementioned matrix, the non-classical damping matrix of the TMD-equipped structures (complete system) is formed"

Thanks

[mhscott]

The authors probably did something with the GimmeMCK integrator to extract the damping matrix

https://portwooddigital.com/2020/05/17/ ... fness-too/