An isotropic material doesn't change with location, it is the same everywhere.nThe geometry is more flexible at the top face where you have circled the corner nodes than deeper down that square hole. There is more relative deformation of the nodes adjacent to each corner node at the top than there is on corresponding nodes deeper down the square hole. More deformation means more stress.nI take your point that the stress is well below yield in the image shown in the original post. Making a mesh convergence plot would be good to practice the technique, not that it is necessary in this example.n