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Tensile Ultimate Stress
You can specify the Material Limits for Isotropic and Transversely Isotropic materials. The following guidelines can help you when you specify the value of the Tensile Ultimate Stress for any type of material:
For Isotropic Materials
For Transversely Isotropic Materials
The value must be positive.
This is a required Material Limits for Modified Mohr failure Criterion
This is a required Material Limits for Unified Material Law (UML).
St1 and St2 must be positive.
 
* St1 is tensile failure stress in the material 1 direction, while St2 is ultimate tensile failure strength in the material 2 direction.
This is a required Material Limits for all the Failure Criterion.
Each field that has a dimension can have its own units. Creo Simulate scales the values you enter when the units change.
When you run a fatigue analysis, Creo Simulate checks that the value of the Tensile Ultimate Stress lies between 50 and 4000 MPa.