You can do a convergence study manually by using Mesh Sizing controls to set the element size in the neighborhood of the peak stress. Solve the model four or five times to get four or five points on a Peak Stress vs Element Size chart.
The element size changes should have a constant ratio. A good ratio is between 1.5 and 2.0
For example, using a ratio of 2.0, if your initial element size was 1 m then you would remesh to get a series of models at element sizes of 1.0, 0.5, 0.25 and 0.125 m.