A unified creep life prediction method and fracture mechanism of high-temperature alloys under multiaxial stress

In this paper, a unified creep rupture life prediction method based on continuum damage me-chanics under multiaxial stress was proposed. By optimizing the traditional skeletal point stress method, the number of models that need to be computed during the simulation was reduced by 5/ 6, and the generality of the method for different notch sizes was significantly improved. Creep tests on Ni-based superalloy round bar specimens with different notch sizes, which verify the accuracy of the method, were conducted. Furthermore, creep rupture mechanism analyses were conducted for different notch sizes by combining finite element simulations with experiments, stress and damage were analyzed, and void growth was explained based on triaxial stress states.

Automated summary

A unified creep rupture life prediction method based on continuum damage mechanics under multiaxial stress was proposed in this paper. By optimizing the traditional skeletal point stress method, the number of models that need to be computed during the simulation was reduced by 5/6, and the generality of the method for different notch sizes was significantly improved. Creep tests on Ni-based superalloy round bar specimens with different notch sizes were conducted to verify the accuracy of the method. Furthermore, creep rupture mechanism analyses were conducted for different notch sizes by combining finite element simulations with experiments, stress and damage were analyzed, and void growth was explained based on triaxial stress states.