Von Mises and principal stress is frame analysis

[lcpinage]

Hello,

I am starting to use the frame analisys in Inventor 2013. Congrats for the frame generator and analysis, really usefull and  easy tool.

But I noticed that you have as result Smax, which is simply the sum of bending stresses due to bending moments + axial stress due to normal force.

But for example if I have a round bar where Smax (Mx) is 10 and Smax (My) is 10 and no or very small  axial stress, the Smax of 20 could never happen in my beam, since max values of Smax (Mx) and Smax (My) are 90 degrees.

Is this Smax used for safety? Is there a way for me to atuomatically calculate the principal stresses and even more von mises or tresca equivalent stress?

Because if I use Smax as parameter to design my structure I might be over-dimensioning it, or also under-dimensioning it, depending on how high are my shear stresses due to torsional or V.

Kind regards!

Luiz Carlos Pinage

[Smater]

I have the same doubt, what is  S Max?

Is the Von Mises or Tresca stress?!!!

best regards