Nonlinear Adaptive Region is useful for nonlinear problems that experience convergence difficulties or accuracy issues because of elemental distortions.

It is also useful for cases where large deformation is small but requires mesh adaptation to better capture the physics and give a more accurate solution.

The Nonlinear Adaptive Region condition requires the Store Results At property to be set to All Time Points in the Output Controls category of the Analysis Settings.

The Nonlinear Adaptive Region condition cannot be used in combination with Weak Springs (COMBIN14 element).

It is necessary that the contact object property Behavior be set to either Symmetric or Asymmetric to use a Nonlinear Adaptive Region in the analysis.