Framework of Fatigue Crack Growth Life Monitoring for Nickel-Based Superalloy GH4169 Based on Thermodynamic Entropy Generation

A framework to monitor the life of the fatigue crack growth (FCG) of the nickel-based superalloy GH4169 based on thermodynamic entropy generation is proposed in this paper. A finite element analysis method combined with ABAQUS and FRANC3D was established to simulate FCG behavior, and a Python program was written to calculate the entropy generation of the chosen thermodynamic system. The results illustrated that the fatigue fracture entropy (FFE) can be treated as a constant that is dependent on temperature. A damage model based on the degeneration-entropy generation theorem was proposed to estimate the life consumption in the FCG process. Finally, the FCG tests were used to compare the estimate from the damage model, and the results showed that this damage model can provide a reliable life monitor of FCG process.