PPT Slide
In applying a yielding criterion, the resistance of a material is given by its yield strength.
In applying a fracture criterion, the ultimate tensile strength is usually used.
Failure criterion for isotropic materials can be expressed in the following mathematical form:
where failure (yielding or fracture) is predicted to occur when a specific mathematical function f of the principal normal stresses is equal to the failure strength of the material, ?c, from a uniaxial tension test.