Hi,
For OC3-Hywind I set wave mode to 0 to have no waves on sea.
Also set
False=TeetDOF, False=DrTrDOF, True=GenDOF, False=YawDOF, False=TwFADOF1, False=TwFADOF2, False=TwSSDOF1, False=TwSSDOF2 to have rigid tower.
Then run the FAST with ADAMSPrep=3 and VSContrl=2. FAST terminated normaly and the output, adm and acf file is created.
After that I ran the ADAMS/Solver using created adm and acf file but encountered with following error.
---- ERROR ----
The simulation stopped at time = 14.973 . Adams cannot solve
the equations of motion.
The greatest error in an equation is 1.2940 in the
equation for GFORCE OC3HywindYawLocked_ADAMS.PlatformLoading_GF .
The greatest change in a variable is 8.84721E-17 in the
variable for PART OC3HywindYawLocked_ADAMS.TipBrake2_P .
Try the following in this order:
1. Use the MAXIT argument on the EQUILIBRIUM, IC, KINEMATICS,
or INTEGRATOR command to increase the maximum number of
iterations.
2. Temporarily change the value of the PATTERN argument on the
EQUILIBRIUM, IC, KINEMATICS, or INTEGRATOR command to
PATTERN = T.
3. Temporarily increase the value of the ERROR argument on the
EQUILIBRIUM, IC, KINEMATICS, or INTEGRATOR command at
time = 14.973 .
4. If one or more forces change rapidly or sharply near
time = 14.973, modify the force or forces.
Do the following to ensure that the number of iterations are
sufficiently large for the Newton-Raphson solver to converge:
1. If you did not have DEBUG/EPRINT in your data set, add the
DEBUG statement with the EPRINT argument and rerun your data
set.
2. Check the EPRINT information at the end of the message file.
3. If both error numbers are below 1.0 and decreasing, increase
the value of the MAXIT argument on the EQUILIBRIUM, IC,
KINEMATICS, or INTEGRATOR command.
4. Rerun your data set.
If the corrector still fails, do the following to force Adams to
update the Jacobian matrix more frequently:
1. Check the error numbers on lines with NEW JAC set to YES.
2. If these numbers decrease significantly after a new Jacobian,
change the value of the PATTERN argument on the KINEMATIC,
EQUILIBRIUM, or IC command to PATTERN = T at time = 14.973.
3. Rerun your data set.
If the corrector still fails, temporarily increase the error
tolerance by doing the following:
1. Issue a SIMULATE command to run until time = 14.973 .
2. Increase the value of the ERROR argument on the INTEGRATOR
command.
3. Issue a second SIMULATE command to run until a time shortly
after time = 14.973 .
4. Decrease the value of the ERROR argument on the INTEGRATOR
command to the value you prefer.
5. Issue a third SIMULATE command to run until the end of the
simulation.
The five steps in the above procedure will allow you to complete the
simulation although the results in the vicinity of time = 14.973
may be less accurate than at other times during the simulation.
The ERROR argument on the INTEGRATOR command determines the
convergence criterion for the corrector as well as the tolerance for
the integration error.
If the corrector still fails, it probably means that this variable is
changing too rapidly or sharply. Do the following:
1. Add the statement
MREQ/id, FORCE, APPFOR = ALL
to your data set.
2. If your data set does not already have it, add the statement
OUTPUT/REQSAVE
3. Rerun the your data set.
4. Read the request file into an Adams postprocessor.
5. Plot the magnitudes of the forces versus simulation time.
6. If one or more forces change rapidly or sharply near
time = 14.973, modify the force or forces.
ALVSIM:STATUS
Simulate status=-124
GLGETL:USER_CMND
STOP
A3TERM:STATUS
Termination status=0
TERM0:EXE_TERM
Adams/Solver execution terminated by subprogram A3TERM
TERM0:CP_TIME
CPU time used = 36.879 seconds
Note I am using steady state wind as follow:
! Time Wind Wind Vert. Horiz. Vert. LinV Gust
! Speed Dir Speed Shear Shear Shear Speed
0.0 10 0 -1 0.1 0.14 0 0
0.1 10 0 -1 0.1 0.14 0 0
I am wondering why FAST runs normally while ADAMS cant.
Any comment will be appreciable to fix the problem.
Thanks,