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Major solutions needed in frlcture analysis are (d) simple and accurate matedal characterization and (ô) easy transferring of malerial data lo cracked structures. ln !h€ proposed methodology. constitutive relationships. including cavity growth and coalescence, are used. Material characterization is based on the simple notched tension lest. Several structural steels have been characterized. especially 4508 steel. and the direct transferring of material data hâs been demonstrated wilh tests on circumf€rentially cracked tension specimens.In addition. the extrapolation of material data io different inclusion conl€nls and temperatures was attempted, with favorabl€ rcsults for the first factor through a specific parameter of the model. Th€ temperature dcpendence of 4508 steel ductiliiy is related to an inverle strain rale effect on the flow curv€: the modeling of this effect gives encoùraging results, but it must be refined to producc an effeclive prediction. KEY WORDSI ductile fracture. damâge mechanics. local approach to fracture, crack iniriation, slable crack growth, 4508 steel. inclusion contenls, notched tension test. fracture mechanics. nonlinear fracture mcchanics Some of the major problems engineers have to cope with in fracture analysis are the following:(a) material characterization, that is. the generation of adequate data from specimen testing, and(ô) the transferring of fracture mechanics data (o the struclural analysis of components.As a mattcr of fact, the generation of matedal data can be money and time consuming: for example, the determination ofJ-Ad resistance curves is still a toilsome task, though some progress was gained with partial unloading cornpliance methods. Frequently, existing material data do not correspond to the specific application (in reference to temperature, strain rate, irradiation. aging, and so forth), and hazardous extrapolations are necessary.

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