Abstract
This paper proposes a new D criterion theory which includes a new physical quantity —the damage parameter, D, a new material property—the ultimate damage, Dc and a new criterion—D ≤ Dc. A number of experimental data are used to verify that the damage parameter, D, describes the degree of the damage near the notch after a certain applied load and that the ultimate damage, Dc, is a material constant independent of configuration of the specimen and the applied load.