Sometimes the elements are too large around high stress gradient areas. The result is that even at the maximum P-level the gradient cannot be accurately represented. The convergence plots may look smooth but never quite reach an asymptote. Also the maximum P-level will be around these large high stress gradient elements. For SPA convergence solutions look for high P-levels in large elements around small features in areas with large stress gradients.
The solution to the problem is to isolate the feature causing the high gradient and force the mesher to create smaller elements in these local areas. This may be done using Surface Regions, Volume Regions or by adding Mesh Control.
