It is usually impractical to reduce the mesh size globally to achieve accurate stresses at critical local regions. Instead, you can reduce the mesh size in specific areas of the model. Refine areas of critical stresses or where there are stress concentration effects that you want to capture accurately. Accuracy is not a big concern where stresses are low. Also, in large areas of simple geometry, a much coarser mesh is sufficient. There are two ways to apply local mesh refinement: