ON THE CONCEPT OF EQUIVALENT PLASTIC STRAIN

Equivalent plastic deformation concept for low cycle fatigue has been studied using seven different criteria. In the case of a magnesium all oy, we have seen that the Konter's criterion results are close to thos e of tension-compression. The physical meaning of equivalent plastic d eformation is doubtful in this case were plastic deformation mechanism s are different in tension-compression and in torsion.