Low cycle fatigue life prediction model for nickel-base single crystal superalloys under multiaxial stress states

摘要

Based on the anisotropic crystallographic theory presented in the paper, a life model of low cycle fatigue (LCF) has been developed for nickel-base single crystal on multiaxial stress states. The life model indicates that LCF life has the power relationship to the total shear strain of octahedral slip systems modified by a parameter of the nonconformity of anisotropic crystallographic deformations. The detail distributions of stresses and strains are analyzed for a hellow cylinder specimen aligned with the {100} axis under tension-torsion LCF loading. The LCF life model presented in the paper has been confirmed successfully by a set of results of tension-torsion LCF tests on CMSX-2 Ni-base single crystal superalloys.