Principal stress plots
In a loaded part, a particular element orientation exists for which all shear stress components are zero. The normals to the elements in this orientation are called principal directions, and the stresses along these normals are principal stresses. You can plot principal stresses by selecting one of the following stress data types named maximum Pricipal, minimum principal and Intermediate Principal Stress. Maximum Principal is the maximum principal stress in traction.
The mean stress occurs during a sinusoidally fluctuating stress.
And finally Von Mises stress is a combination of the three principal stresses at any one particular location. This resultant is usually compared to the material yield strength to determine if failure will occur under the defined loading condition. You can plot this by selecting the Von Mises stress data type from the Result Component list in the Data Selection group.
Excellent explanation Blas!
Yes, I present ususally Max Principal stress as Tension (positive value) and Min Principal as Compression (negative value).
It's good to present it as additional result.