A Review of the Interaction of Creep and Fatigue

Abstract

hiany components in supersonic aircraft and modern power plant operate under cyclic conditions at increased temperatures at which creep processes also occur. Solving associated material problems depends, to a major extent, on understanding the various factors influencing behaviour, such as the effect of stress or strain cycling, dwell periods, temperature, notches, environment, multiaxial stress, ductility, and the effect of prior testing on subsequent endurance. T h e various methods of testing are briefly described and the mode of failure where there is interaction between creep and fatigue is discussed. Method5 for predicting deformation and life are also presented. Finally, the review concludes with suggestions for future work.

Continuum damage mechanism-based life prediction for Ni-based superalloy under complex loadings

“…Complex loadings due to maneuver transients and start-stop in service conditions, high temperature resulting from the gas environments and complex geometry features on account of cooling designs cause a complex mechanism of blade failures. The traditional life models, such as Masson-Coffin method, Ostergren model [4], frequency separation model [5], ductility exhaustion model [6], strain-range partitioning model [7] and so on, fail to meet such a wide range of loading conditions because of the insufficient number of parameters. In addition, as the components simultaneously experience damage from fatigue-, creep-, oxidation-related mechanisms, any models which consider only one of these damages are not sufficiently accurate to describe such a complex damage procedure.…”