Good morning everybody.
I ask help from this forum for the following problem.
I’ve set up a linear static analysis of a rectangular shape part (12.7mm x 12.7mm) with a thickness of 0.254mm.
I’ve set up the mesh with thetraedral parabolic elements, with a dimension of 0.15 mm.
I’ve applied a fixed constraint and a load.
The material is a brittle material with tensil strenght of 220 MPa and a compressive strenght of about 2000 MPa, so in the material properties I set the parameter tensile streght to 220 MPa, compressive strenght 2000 MPa, I set the yield strenght the same of the tensile strenght, finally I set the failure criteria to Principal stress.
After running the analysis I check the Max principal stress and the Min principal stress.
The maximum stress of the Max principal stress is about 160 MPa, and the minimum of the Min principal stress is about -300MPa.
So to calculate the safety factor I do 220/160 = 1.375 .
But when I check the safety factor result from the analysis, the result shows a minimum safety factor of 2.2 in a point of the part that is different from the point where is the maximum stress.
How this could be possibile?
I’ve done some mesh refinments, and the result converge, so I determined thai ther is not a problem with mesh.
Thank you very much
