Development of FAST Platform Module

Hi all,

I would like to ask some questions related to the development of mooring line modules and compiling it with FAST.
I followed the instruction from NWTC Programmer’s Handbook, Appendix E: Module Template, to create a simple Spring module. The idea is to replace the mooring lines attached at the fairlead positions with Springs that have linear stiffness in surge, sway, and heave direction. I created Spring.f90 and Spring_Types.f90 for this purpose.

Afterwards, I added the spring mooring module in the FAST_Subs.f90 and FAST_Types.f90 similar to how MAP and FEAMooring are being called. All compiled with no errors, and the solution was built into FAST_dev_Debug_Win32.exe.
The problem occurs when I tried to run it using Test22.fst with CompMooring set to the new Spring module. An error related to ElastoDyn and Spring module states “both meshes must be committed before they can be mapped”.
Using Appendix G: Mesh Module and Types, I then added meshes to the Spring module, but I was not able to run the certified Tests (Test 22,23,24).
Should I instead connect the Spring module similar to SubDyn instead of MAP or FEAMooring?

Thank you for your attention and I look forward to your reply.

Best regards,

Yehezkiel Tumewu
M.S. Student Structural and Earthquake Engineering
Department of Civil, Structural and Environmental Engineering
University at Buffalo, The State University of New York