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Abstract: A
total strain version of strain energy partitioning (TS-SEP) is
formulated based on strain energy partitioning(SEP), utilizing the
method of HALFORD and SALTSMAN for developing TS-SRP. Like TS-SRP, TS-SEP characterizes the behavior of alloys in two aspects: Failure
behavior and flow behavior. Elas-tic strainrange-life relations are
established by using the empirical equations of flow behavior of
alloys. Total strainrange-life relations are given by summing elastic
strain-range-life relations and inelastic strainrange-life relations.
TS-SEP can be used for creep-fatigue life prediction without
partitioning the inelastic strainrange, so it is applicable in the
low-strain, long-life regime where SEP is difficult to use. Then, TS-SEP
is evaluated and verified by using two advanced nickel-base superalloys, Rene95 at 650 ℃ and AF2-1DA at 760 ℃. The results indicate that TS-SEP
can predict the creep-fatigue life of Rene95 at 650 ℃ and AF2-1DA at 760
℃ more reliable than SEP. The agreement of the predictions with the
observed lives of the baseline tests is quite good for TS-SEP, with
97.5% percent of the Rene95 baseline data being predicted to within
factors of two, and 100% of AF2-1DA, and the scatter band of TS-SEP for
verification tests is lower than all other three methods (SEP, TS-SRP, SRP).
Key words: Strain energy partitioning
Strainrange partitioning High temperature low cycle fatigue
Key words: Creep-fatigue Life prediction
CLC No: O346.2
Received 20050927, received in revised form 20060801
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