solidworks factor of safety question

[durablack2]

I'm running a static fea simulation in solidworks. I do not understand why the factor of safety output by solidworks is different than my calculation using the maximum Von Mises stress output from the simulation and the yield stress.

Solidworks FOS = 1.52
Max Von Mises stresses = 293 MPa
Yield stress = 620 MPa
My FOS = yield strength / max stress = 620 / 293 = 2.1

The factor of safety result is set to look at Von Mises stresses, not the other possible stresses. I've attached my solidworks file.

Can someone help me understand what I am not considering correctly in this calculation?

 

[gravityandinertia]

File this as a bug to the reseller. One of two things is happening:

1. This is a legitimate bug.
2. The software is taking the stress at a gauss point, rather than over the element or at a node as the software does and this is creating a discrepancy particularly at a sharp corner that appears to me to be a singularity.

Personally, my hunch is #2. Either way, contact your reseller.