Accessing the generalized stiffness matrix in WISDEM

Wind & Water Computer-Aided Engineering Software Tools
1

Dear Community,

I’m currently working with WISDEM and I’d like to know if there is a simple way to extract the generalized stiffness matrix. While looking into this, I found that pyFrame3DD might be able to handle this, but I’m not completely sure.

Has anyone successfully accessed or exported the global stiffness matrix from WISDEM or pyFrame3DD directly?

Thanks in advance for your help!

Best regards,
Adele

2

Hi Adele,

It is possible to accomplish this, but it is not a smooth workflow as Frame3DD does not naturally expose the underlying mass or stiffness matrices to pyFrame3DD. This will require a tiny bit of comfort with the WISDEM source and familiarity with Frame3DD as a standalone tool. The steps are:

  1. Make sure you install WISDEM in “editable” mode
  2. Uncomment the “debug” line near the pyFrame3DD call relevant to you. You didn’t mention if you need the stiffness matrix of the blade or tower or offshore foundation. The applicable tower code line is here. The blade one is here.
  3. Run WISDEM and let it write out the Frame3DD input file.
  4. You will likely have to modify the Reactions section of the Frame3DD file to use 1s or 0s, as opposed to the alternative method that pyFrame3DD uses.
  5. Download and install/compile Frame3DD from here.
  6. Run Frame3DD with the input file generated by WISDEM using the -w flag to write out mass and stiffness matrices. See this section of the Frame3DD docs.

Good luck and I hope it works for you!
Garrett