With the combination of increased CPU speed and advances in simulation algorithms, nonlinear analyses have become more mainstream and are now reliably and more quickly solved. One example of the advancement of algorithms is the mesh Nonlinear Adaptivity (NLAD) capabilities in ANSYS® Mechanical™ Workbench™ and MAPDL (Classic ANSYS).
Nonlinear adaptivity refers to the capability of the FEA solution process to adapt to changing conditions during a nonlinear analysis. The solution process uses a feedback mechanism to discretely or continuously adjust some internal parameters automatically so that an accurate and convergent solution is obtained.
Adaptive meshing is an example of an adaptive process. For instance, in highly nonlinear problems, excessive calculated deformation can cause analyses to fail due to poorly shaped elements. In these cases, a remesh in the middle of the nonlinear solve can return the mesh back to well-shaped elements and allow the solve to continue. In many cases, this is the only way to get a high deformation solve to converge properly.