Mechanical enables you to perform nonlinear adaptive analyses using the Nonlinear Adaptive Region and Geometry Based Adaptivity options found in the Conditions drop-down menu of the Environment context tab.
Nonlinear adaptivity is a capability of the solution process that enables the application to adapt to changing conditions during a nonlinear analysis. The solution process uses a feedback mechanism to discretely and continuously adjust internal parameters automatically so that you can obtain an accurate and convergent solution.
You use these conditions to either change the mesh during the solution process or to model the boundary geometry accurately during mesh adaptivity: