Modelling the influence of plasticity induced softening on the low cycle fatigue and crack propagation behaviour of a nickel-based superalloy

• Cyclic hysteresis loops generated during high-temperature, isothermal, low-cycle fatigue testing of the nickel-based superalloy RR1000 revealed a gradual decrease in elastic modulus of up to 25 % compared to the initial value in dependence of the accumulated plastic strain. Based on the experimental observations, a material model was developed and implemented within a finite element solver to investigate the effect of degrading stiffness on crack growth laws and crack growth predictions. It was shown that the stress intensity factor diminished by 6 to 8 % and crack growth rates were 14 to 20 % higher when stiffness degradation was accounted for.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Teknisk mekanik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Applied Mechanics (hsv//eng)

Nyckelord

Cyclic nano-indentation; Stress intensity factor; Crack propagation; Crack growth; Nickel-based superalloy; High temperature

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