Effect of Notch Severity on Thermomechanical Fatigue Life of a Directionally-solidified Ni-base Superalloy
The aim of this research is to understand the influence of notches under thermomechanical fatigue (TMF) in a directionally-solidified (DS) Ni-base superalloy. Experiments were performed utilizing linear out-of-phase (OP) and in-phase (IP) TMF loadings on longitudinally-oriented smooth and cylindrically-notched specimens. Several notch severities were considered with elastic stress concentrations ranging from 1.3 to 3.0. The local response of the notched specimens was determined using the finite element method with a transversely isotropic viscoplastic constitutive model. Comparing the analysis to experiments, the locations observed for crack nucleation in the notch, which are offset from the notch root in DS alloys, are consistent with the maximum von Mises stress. Various local and nonlocal methods are evaluated to understand the life trends under OP TMF. The results show that a nonlocal invariant area-averaging method is the best approach for collapsing the TMF lives of specimens with different notch severities.
notched specimens thermomechanical fatigue Ni-base superalloy notch analysis
Patxi Fernandez-Zelaia Richard W. Neu
Woodruff School of Mechanical Engineering,Georgia Institute of Technology,Atlanta,Georgia,30332,USA Woodruff School of Mechanical Engineering,Georgia Institute of Technology,Atlanta,Georgia,30332,USA;
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）