Using FEAMooring for OC4 in OpenFAST

Dear Dr Jonkman
I am trying to use the FEAMooring module for fatigue analsysi of tower base of OC4_Semi submersible platform, but the output for forces at the tower base is printed out as “NAN” in the output file, while I am using MoorDyn the output are printed correctly.

Do you have any idea what causes this error?

Thank you

Kind regards


Dear Milad,

We provided an FEAMooring input file for the OC4-DeepCwind semisubmersible model as an example in the OpenFAST r-test, but to be honest, this model has never been tested. I would guess that you may have to double-check that the FEAMooring inputs are set properly and you may have to play around with solver options (e.g., time steps) to get the model to run. I haven’t ran FEAMooring in a while, but if I recall correctly, OpenFAST may need to be compiled in double precision for FEAMooring to function properly.

FYI: We have generally been using MoorDyn in place of FEAMooring when needing to model mooring dynamics.

Best regards,

Thanks a lot