Dear Jason,
I am facing exactly the same issue of convergence for some simulations, with OpenFASTv2.3.0 and a time step of 0.0001s
‘‘FAST_Solution:FAST_AdvanceStates:B1:BD_GA2:BD_DynamicSolutionGA2:Solution does not converge after
the maximum number of iterations
FAST encountered an error at simulation time 324.34 of 650 seconds.
Simulation error level: FATAL ERROR
Aborting OpenFAST.’’
Correct me, if I am wrong. Through linearization I obtained state matrices. Considering: Mod(A-lamda*I)*X=0 , I have obtained eigen vector. Using FFT, I can obtain natural frequencies, right? In your previous comment you mentioned ‘dropping order_elem’. Did you mean to reduce the value in BeamDyn input? Currently, I am using a value of 4.
I am not sure, if I understand you correct or not. In the thread ‘BeamDyn - Solution does not converge after the maximum number of iterations · Issue #366 · OpenFAST/openfast · GitHub’ you mentioned that for linearization analysis parked/idling is sufficient. But to calculate the operational frequencies the turbine needs to be in operational condition, right?
Thanks and kind regards
Abhinay Goga