An investigation of the nonlinear creep damage accumulation of different materials: Application of a novel damage model

Abstract

Variable creep load is one of the most important failure modes for hot-component of aero-engine. To accurately predict creep damage and remaining life, a novel nonlinear creep damage accumulation model is proposed based on the Wilshire function and isodamage line, which takes the influence of load history into account and uses ultimate tension strength to compensate the temperature effect. Experimental result of tests on four kinds of material were utilized to verify the accuracy of the proposed model and to compare it with existing models. It was determined that the novel model was better at predicting damage accumulation than all others model. Furthermore, the proposed model elucidates the evolutionary process of creep damage, and four cases of damage evolution process are discussed.

Modeling the creep deformation and damage evolution of superalloy GH4169: Application of a novel damage constitutive model based on continuum damage mechanics

“…Post-audit validation was also conducted to verify the predictive ability of the novel model, and it was determined that the model displays satisfactory predictive results. Interestingly, the nonlinear creep damage accumulation effect was revealed by the novel model, which was consistent with our previous experimental results 29 . And this phenomenon further showed the accuracy of the damage constitutive model from the aspect of damage accumulation process.…”

“…In this case, the total life is reduced. This nonlinear damage accumulation effect has been evaluated quantitatively by using isodamage line theory for superalloy GH4169 in recent research 59 , i.e. the total life will be reduced when high stress condition was applied first.…”

A novel damage constitutive model for creep deformation and damage evolution prediction

“…Post‐audit validation was also conducted to verify the predictive ability of the novel model, and it was determined that the model displays satisfactory predictive results. Interestingly, the nonlinear creep damage accumulation effect was revealed, which was consistent with our previous experimental results 26 . And this phenomenon further showed the accuracy of the damage constitutive model from the aspect of damage accumulation process.…”

“…The total life is reduced in this case, and vice versa. This nonlinear damage accumulation effect has been evaluated quantitatively by using isodamage line theory for superalloy GH4169 in recent research 26 ; that is, the total life will be reduced when high stress or temperature condition was applied first, while the total life will be increased when low stress or temperature condition was applied first. It should be pointed out that the opposing situation was also found for some other materials 46 .…”

Design of a novel creep testing machine to investigate the creep life history of austenitic steel foil at elevated temperature

“…Experimental and theoretical studies of creep and creep fracture 55,56 have been relying on a limited number of parameters. Nevertheless, replacing the conventional approaches with procedures leads to offering other constitutive equations that describe the entire creep curve.…”