Iterative Solver Parameters - Practical Recommendation

Apply the following methods of iteration preconditioning when NoRHS > 2 or nModes > 5.

If checked, use Multilevel with ICCF preconditioning
If not checked, use Non-multilevel with ICCF preconditioning

NoRHS denotes a number of load cases in linear statics. nModes is the number of eigenmodes for modal analysis.

Moreover, a user should try to apply the ICCF approach if available RAM is sufficient. Also apply the Vinget regularization for a trial solution when analysis is performed for the first time after model preparation.

If none of the iterative methods show satisfactory convergence, it indicates that an ill-conditioned problem has been met. Usually this occurs due to errors in the generated calculation model, such as unrestricted structure parts, unreal geometrical or physical parameters, incorrect units, or ill mesh.