The Tensile Yield Stress is the required Material Limits for the Maximum Shear Stress (Tresca) failure criterion. When you select Maximum Shear Stress (Tresca) as the Failure Criteria, you must specify the value of the Tensile Yield Stress.

Enter a positive value for yield stress.

If you do not specify a value, Creo Simulate does not compute failure indexes for this material.

The software calculates Tresca failure index as follows:

failure_index = 2 x Maximum Shear Stress/Tensile Yield Stress

Each field that has a dimension can have its own units. Creo Simulate scales the values you enter when the units change.

Generally the maximum shear stress(Tresca) failure criterion is used in the definition of ductile materials.