Question on SSI modelling

Hi @Jason.Jonkman

I am working on an onshore turbine and have following SSI data. How could I use this data for flexible foundation modelling. As far as I know, we need to have a SSI stiffness matrix to model the flexible foundation in subdyn. I have torsional spring model.

Thank You

Dear @Tom.Jose,

I’m not familiar with the data you are sharing, but if you intend to utilize the SSIfile in SubDyn, what you specify is the 6x6 stiffness matrix between the pile and soil at the reaction joint. The simplest form of this matrix would be to neglect all cross-coupling terms, resulting in a diagonal matrix that is equivalent to 3 translation springs and 3 rotational springs. Of course, you can zero-out rows and columns associated with any of the 6 reaction joint degrees of freedom you constrain.

Best regards,

Dear Jason,

I am modelling the soil-structure interaction by inserting p-y curves into the soilDyn.f90 for momopile-supported offshore wind turbine. However, some errors confused me a lot, relative messages are attached below. Thanks a lot!

Best regards,

Dear @Kevin.Chang,

By “p-y curve”, presumably you are referring to the SubDyn SSIfile.

From the error message, it appears that the data in your SSIfile contains NaNs or is not being read properly by SubDyn. If you haven’t already, I would start with the documentation and sample SSIfile from here: Input Files — OpenFAST v3.5.1 documentation.

Best regards,

Dear @Kevin.Chang,

Can you clarify if you modified the SoilDyn source code to account for p-y curves (in your message, you refer to the soildDyn.f90 file)?

Could you also clarify how the p-y curve that you are trying to include in the model looks like?

Kind regards