A nonlinear analysis may fail to converge due to a number of reasons. Some examples may be initially open contact surfaces causing rigid body motion, large load increments, material instabilities, or large deformations that distort the mesh resulting in element shape errors.
In the Mechanical application, you can review this unconverged result as well as any converged results at previous time points. These results are marked in the legend of contour/vector plots as ‘Unconverged’ indicating that these results must be used only for debugging purposes. Note that a plot of Newton-Raphson residuals is a very useful tool to identify regions of your structure that led to the convergence difficulty.
Note:
Results in Solution Combination objects that use partial solutions will not be solved. You can view partial results but cannot use them in further post/solution work.
Newton-Raphson residuals is a very useful tool to identify regions of your structure that led to the convergence difficulty.
The handling of unconverged solutions is the same for both probes and results, with the following exception: reaction probes scoped to a Compression Only boundary condition cannot display results if the solver did not converge.