ASME Analysis

[Richard1977]

I’m trying to analysis a pressure vessel by FEM according to ASME code, This analysis must be make with maximum shear stress theory (Tresca). It is possible analysis with NX6?

 

[BlasMolero]

Dear Richard,
The Tresca yield criterion is based on the Maximum Shear stress theory. This theory predicts failure of a material to occur when the absolute maximum shear stress (tmax) reaches the stress that causes the material to yield in a simple tension test. The Maximum shear stress criterion is used for ductile materials.
• tmax ? slimit/2
• tmax is the greatest of txy, tyz and txz
Where:
• txy = (s1 - s2)/2;
• tyz = (s2- s3)/2;
• txy = (s1- s3)/2
• and s1, s2 and s3 to be the principal stresses.

Hence:
Factor of safety (FOS) = slimit/(2*tmax)

In NX AdvSim you can plot the Maximun Shear stress, as well as the three principal stresses, vonMises, Octaedral and Mean stress that will allow you to assess your results according ASME requirements.

Best regards,
Blas.