Cyclic Ductility,Cyclic Strength and Fatigue Crack Propagation of Metals and Alloys.

摘要

Fatigue crack propagation has been related to the cyclic stress-strain and life-strain response of materials by means of a ductility exhaustion mechanism. The da/dn-delta K relationship has been derived from the assumption that an elemental crack extension occurs when the sum of the fractional fatigue life of an element at various cycles is equal to unity. Experimental fatigue crack propagation data of representative metals and alloys have been compared with that predicted from their low cycle fatigue properties. The threshold delta K behavior has been explained in terms of the existance of a threshold plastic strain amplitude. (Author)