Radiation damping, Crad, is not working appropriately in OpenSees.

[Danielaait]

I am using OpenSees and winkler spring to represent the foundation. Since my ground shaking is not intense, I have chosen 'Foundation condition = 3' which is elastic vertical and horizontal springs.

Could you please tell me how OpenSees considers soil radational damping when I choose 'Foundation condition = 3'?

When I change the value of Crad, radiation damping ​ratio, the output is the same. Results are not changing as I change Crad value.

I have also checked the paper by Prishati Raychowdhury and Tara C., "ShallowFoundationGen OpenSees Documentation" 2008 (Example 1: shear frame). It doesn't show any difference if I change Crad value.

How can I solve this problem? My goal is to represent the dynamic impedance of Soil-structure interaction by linear spring and dashpot.



Please help me