Dear Jason,
Thanks for the reply. I have few follow-up questions.
Q1. As you advised I have tried with different initial conditions. For the static stability case and free decay test cases, the surge displacement and pitch rotations have a mean value of 0.4 m and (-)1.5 deg. However, I was expecting a mean value of zero for all platform displacements and rotation. The same mean value is getting reflected in other DLCs such as 2.1 and 3.1. Does this happen due to the stability of the substructure?
Q2. I have not changed the mass and the stiffness of the system for DLC 3.1. I have tried with time step values of 0.05, 0.0125 and 0.001 sec. The error (shown in snapshot 1 below) is happening for time step 0.001 and 0.0125 sec and error (shown in snapshot 2 below) is happening for time step of 0.05 sec. All the above errors are occurring when Yaw DOF is enabled and Drivetrain rotational-flexibility DOF is disabled. If both Yaw DOF and Drivetrain DOFs are disabled simulations are running fine. Is there any problem with the Yaw DOF?
Could you please help me in resolving the above issues?
Regards
Ramya