Proposal of a new concept on creep fracture remnant life for a precracked specimen

The creep life time of a smooth specimen can be predicted using existing la ws for creep deformation and steady state creep rate. When crack growth beh aviour is involved, it is necessary to construct a law of creep crack growt h rate to predict creep fracture life. Creep fracture life can be measured by integrating the law of creep crack growth rate. One example is the creep crack growth rate, represented by the parameter Q*. In this study, we inve stigated the applicability of this prediction method to creep fracture remn ant life for a cracked specimen. The Omega criterion is proposed to predict creep fracture remnant life for a smooth specimen for creep ductile materi als. In this study, the correlation between Q*(L), derived from the paremet ers Q* and Omega is investigated. The correlation between Q(L)* and Omega p rovided a unified theoretical prediction law of creep fracture remnant life for high-temperature creep-ductile materials in the range from smooth to p recracked specimens.