Problem in MAP and MoorDyn

Dear Dr Jason,

I want to add connections to make a chain-cable-chain morring system with 1:27:15 of the whole line, but I encounter fatal error.
This is the input file of MoorDyn, the MAP is similar.
2 NTypes - number of LineTypes
Name Diam MassDen EA BA/-zeta Can Cat Cdn Cdt
(-) (m) (kg/m) (N) (N-s/-) (-) (-) (-) (-)
main 0.147 432.2 1.63E9 -1.0 0.8 0.25 2.0 0.4
main1 0.084 29.5 3.88E8 -1.0 0.8 0.25 2.0 0.4
---------------------- CONNECTION PROPERTIES --------------------------------
12 NConnects - number of connections including anchors and fairleads
Node Type X Y Z M V FX FY FZ CdA CA
(-) (-) (m) (m) (m) (kg) (m^3) (kN) (kN) (kN) (m^2) (-)
1 Fixed 511.5516 0 -150 0 0 0 0 0 0 0
2 Connect 383.485 0 -120.103 0 0 0 0 0 0 0
3 Connect 69.142 0 -46.718 0 0 0 0 0 0 0
4 Vessel 57.5 0 -44.0 0 0 0 0 0 0 0
5 Fixed -255.7758 -443.0167 -150 0 0 0 0 0 0 0
6 Connect -191.7425 -332.108 -120.103 0 0 0 0 0 0 0
7 Connect -34.571 -59.879 -46.718 0 0 0 0 0 0 0
8 Vessel -28.75 -49.79646 -44.0 0 0 0 0 0 0 0
9 Fixed -255.7758 443.0167 -150 0 0 0 0 0 0 0
10 Connect -191.7425 332.108 -120.103 0 0 0 0 0 0 0
11 Connect -34.571 59.879 -46.718 0 0 0 0 0 0 0
12 Vessel -28.75 49.79646 -44.0 0 0 0 0 0 0 0
---------------------- LINE PROPERTIES --------------------------------------
9 NLines - number of line objects
Line LineType UnstrLen NumSegs NodeAnch NodeFair Flags/Outputs
(-) (-) (m) (-) (-) (-) (-)
1 main 12.21 1 1 2 -
2 main1 329.58 27 2 3 -
3 main 134.27 11 3 4 -
4 main 12.21 1 5 6 -
5 main1 329.58 27 6 7 -
6 main 134.27 11 7 8 -
7 main 12.21 1 9 10 -
8 main1 329.58 27 10 11 -
9 main 134.27 11 11 12 -

The following are the errors of MoorDyn and MAP.
Running MoorDyn (v1.01.02F, 8-Apr-2016)
Creating mooring system. 3 fairleads, 3 anchors, 6 connects.
Catenary solver failed for one or more lines. Using linear node spacing.
Catenary solver failed for one or more lines. Using linear node spacing.
Catenary solver failed for one or more lines. Using linear node spacing.
Catenary solver failed for one or more lines. Using linear node spacing.
Catenary solver failed for one or more lines. Using linear node spacing.
Catenary solver failed for one or more lines. Using linear node spacing.
Catenary solver failed for one or more lines. Using linear node spacing.
Catenary solver failed for one or more lines. Using linear node spacing.
Catenary solver failed for one or more lines. Using linear node spacing.
Finalizing ICs using dynamic relaxation.

FAST_InitializeAll:FAST_Init:ValidateInputData:It is highly recommended that time-marching output
files be generated in binary format when generating checkpoint files.
FAST_InitializeAll: NaN state detected.

FAST_InitializeAll:FAST_Init:ValidateInputData:It is highly recommended that time-marching output
files be generated in binary format when generating checkpoint files.
FAST_InitializeAll:MAP_Init:MAP_FATAL[59] : Approached a geometric limitation that the MSQS model
is unable to solve. LMax = 14.359991 [m].
MAP_FATAL[59] : Approached a geometric limitation that the MSQS model is unable to solve. Line
segment 3.
MAP_FATAL[88] : Line failed.
MAP_FATAL[79] : Solution failed in MinPack LMDER.
MAP_ERROR[7] : Failed to write node information to the MAP summary file.
MAP_FATAL[37] : Failed to write the MAP summary file.

Thank you for your help,
Best regards.

Dear Yuanzhao,

It seems that in your connection properties you have a large spacing between nodes 1, 2, and 3, but a small spacing between nodes 3 and 4. But in your line properties, you’ve set the shortest line between nodes 1 and 2, and long lines between nodes 2, 3, and 4. This seems like an error in the input file that can be fixed by swapping lines 1 and 3. (Likewise for the other two lines.)

Best regards,

Dear Dr. Jonkmann,

I’m trying to model a floating wind turbine but I’m constantly getting this error. I can’t understand how to solve the problem.
this is the Moordyn Input file:

--------------------- MoorDyn Input File ------------------------------------
Mooring system for the DTU 10MW Reference Wind Turbine installed on USTUTT INNWIND Triple Spar floater, v0.03
FALSE Echo - echo the input file data (flag)
----------------------- LINE TYPES ------------------------------------------
1 NTypes - number of LineTypes
Name Diam MassDen EA BA/-zeta Can Cat Cdn Cdt
(-) (m) (kg/m) (N) (N-s/-) (-) (-) (-) (-)
main 0.00517 0.165 1.13E6 1.0 -999.9 -999.9 -999.9 -999.9
---------------------- CONNECTION PROPERTIES --------------------------------
6 NConnects - number of connections including anchors and fairleads
Node Type X Y Z M V FX FY FZ CdA CA
(-) (-) (m) (m) (m) (kg) (m^3) (kN) (kN) (kN) (m^2) (-)
1 anchor 10 0.0 -3.0 0 0 0 0 0 0 0
2 anchor -5.0 8.67 -3.0 0 0 0 0 0 0 0
3 anchor -5.0 -8.67 -3.0 0 0 0 0 0 0 0
4 fairlead 0.43 0.0 0.145 0 0 0 0 0 0 0
5 fairlead -0.215 0.37 0.145 0 0 0 0 0 0 0
6 fairlead -0.215 -0.37 0.145 0 0 0 0 0 0 0
---------------------- LINE PROPERTIES --------------------------------------
3 NLines - number of line objects
Line LineType UnstrLen NumSegs NodeAnch NodeFair Flags/Outputs
(-) (-) (m) (-) (-) (-) (-)
1 main 10.167 75 1 4 -
2 main 10.167 75 2 5 -
3 main 10.167 75 3 6 -
---------------------- SOLVER OPTIONS ---------------------------------------
0.001 dtM - time step to use in mooring integration (s)
3.0e6 kbot - bottom stiffness (Pa/m)
3.0e5 cbot - bottom damping (Pa-s/m)
0.25 dtIC - time interval for analyzing convergence during IC gen (s)
300.0 TmaxIC - max time for ic gen (s)
4.0 CdScaleIC - factor by which to scale drag coefficients during dynamic relaxation (-)
0.01 threshIC - threshold for IC convergence (-)
------------------------ OUTPUTS --------------------------------------------
FairTen1
FairTen2
FairTen3
AnchTen1
AnchTen2
AnchTen3
END
------------------------- need this line --------------------------------------

and this is the error I get:

Running HydroDyn (v2.05.01, 27-Jul-2016).
Generating incident wave kinematics and current time history.
Reading in WAMIT output with root name “.\HydroData\TripleSparScaledModel”.
Computing radiation impulse response functions and wave diffraction forces.

Intialization: MAP_WARNING[1] : Extra characters are present in the cable librar
y portion of the MAP input file. word: <(-)>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file. word: <1>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file. word: <2>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file. word: <3>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file. word: <------------
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file. word: <0.001>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file. word: <3.0e6>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file. word: <3.0e5>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file. word: <0.25>
MAP_WARNING[1] : Extra c

FAST_InitializeAll:MAP_Init:MAP_WARNING[1] : Extra characters are present in the
cable library
portion of the MAP input file. word: <(-)>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file.
word: <1>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file.
word: <2>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file.
word: <3>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file.
word: <------------
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file.
word: <0.001>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file.
word: <3.0e6>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file.
word: <3.0e5>
MAP_WARNING[1] : Extra characters are present in the cable library portion of th
e MAP input file.
word: <0.2

FAST encountered an error during module initialization.
Simulation error level: FATAL ERROR

Aborting FAST.

Thanks a lot in advance
Best regards
Masih

Dear Masih,

I’m not too familiar with the MoorDyn source code, but I do see a few oddities in your input file, which might cause problems in MoorDyn:

  • The mooring line added mass and damping coefficients (Can Cat Cdn Cdt) should not be negative.
  • The connection node type should be one of the keywords “Fixed”, “Vessel”, or “Connect”, not “anchor” or “fairlead”.
  • I’m not sure if MoorDyn allows nodes to pass above the still water level i.e. whereby Z > 0.

You could also set Echo to True to debug problems in the reading of the input file.

Best regards,

Dear Dr. Jonkmann,

Thanks a lot for your answer. I figured it out. I had a wrong input in the .fst file.

Thank you again.

Masih

Dear Dr. Jason,

I’m using MoorDyn for FAST simulation of a semisub FOWT. FAST runs successfully when all six DoFs of the platform are true. But for a special case (in which I turned off PtfmSwDOF), I get the following error:
“MD_UpdateStates: NaN state detected.”


I’m appreciated if you could inform me what this error tells. I see that there is also a tower strike error at the same time. I’m really confusing that why the tower strike occurs.

Best regards,
Yingyi Liu

Dear Yingyi,

It appears that your model has suffered some sort of instability (physical or numerical), resulting in a large platform displacement, large tower deflection (with a tower strike), and eventually NaNs in the solution. You should figure out what in the model is causing the instability. I suggest using “Search…” in the upper-right to find how other users have resolved similar problems in the past.

Best regards,