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@RyanDavies19 RyanDavies19 commented Apr 9, 2025

Feature or improvement description
This PR addresses a few minor MoorDyn bugs and improves outputs to the console.

  1. Resolved a bug in the viscoelastic models for both constant and load dependent dynamic stiffness, where the viscoelastic springs in the segments would initialize as unstretched causing an initial spike in tension and a ringing in the line that persisted after dynamic relaxation. Now the segments are stretched according to the catenary solver results.
  2. Resolved a bug in printing to the console during initialization that caused issues with MATLAB as reported in Bug report: MoorDyn Initialization Output to Command Line #2653. This was solved by adding the disableOutTime flag from MD-C to MD-F. This turns off the console printing of FairTens during MD initialization
  3. Added an error check for users who try to using a damping ratio with a stress-strain lookup table
  4. Resolves a bug in FAST.Farm where MoorDyn did not receive the platform 6DOF positions during initialization. To solve, added a 6x1 PlatformPosInit array to the FAST params, which is assigned the values of Init%OutData_ED%PlatformPos right after ED_Init is called. This allows MoorDyn to access the ED initial platform position as defined in the ED input file.

Related issue, if one exists
#2653

Impacted areas of the software
MoorDyn
FAST.Farm
FAST glue code

Additional supporting information
This will require a change to the r-tests for FAST.Farm MD_Shared (the test should fail in this PR). Corresponding PR is OpenFAST/r-test#149

Test results, if applicable
The following images show the results of the FAST.Farm bug fix.

Before fix:
Screenshot 2025-04-09 at 9 46 26 AM
After fix:
MD_shared_fixed

Behavior of FAST.Farm in steady state is preserved. Below is a comparison of the MoorDyn outputs for the MD-Shared regression test before and after the fix.
Screenshot 2025-04-09 at 9 29 41 AM

…damping ratio, adds flag to disable calls to WrOver in initalization that caused MATLAB issues
@andrew-platt andrew-platt merged commit 53f8c0b into OpenFAST:dev Apr 14, 2025
22 checks passed
@RyanDavies19 RyanDavies19 deleted the MD_general_bugfixes branch April 14, 2025 18:05
@RyanDavies19 RyanDavies19 mentioned this pull request Apr 15, 2025
8 tasks
andrew-platt added a commit to abhineet-gupta/AG_openfast that referenced this pull request Apr 15, 2025
andrew-platt added a commit to abhineet-gupta/AG_openfast that referenced this pull request Apr 15, 2025
When I merged the `OpenFAST/dev` in, I clobbered a change from PR OpenFAST#2746
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2 participants