I'm working on a simple plate, as you can see posted here, and I am trying to get stress values at the corners circled in red at different fillet radii. I've run into a problem where the stress trend breaks as the radius of the corner goes to 0mm (no fillet).
The loading on the part can be seen in the image, the forces are 1500lbs each, and material is AISI 304 at a 2mm thickness.
Here are my max stress results from my simulations:
No Radius: 234.6MPa
1mm: 523.4 MPa
2mm: 427.8 MPa
4mm: 331.2 MPa
6mm: 283.2 MPa
10mm: 248 MPa
From 1mm to 10mm the max stress gets lower as you would expect, but the max stress at a pure corner (0 radius) goes even lower than with a 10mm radius!
Does anyone have any insight as to why this is happening?
what does the mesh look like? this is basically a singularity, it will bounce up and down from a stress perspective. converge on displacement first and then see if you can settle down the stress by improving the mesh. just because you add a radius doesn't mean you can guarantee elimination of a singularity.