Substrate Damage Modeling for Advanced Turbine System Airfoils

The Department of Energy (DOE) is developing advanced hydrogen-fired and oxy-fueled turbine technologies that are projected to operate with turbine inlet temperatures (TIT) of 1425°C and 1760°C, respectively. At these temperatures, the airfoil will require not only internal cooling, but also stable thermal barrier coatings (TBCs) in order to achieve extended service operation in these advanced high steam-containing environments. We previously developed a computational methodology, based on three-dimensional finite element analysis (FEA) and damage mechanics, for predicting the evolution of creep in the hydrogen-fired and oxy-fueled airfoils. This methodology has been extended to fatigue damage evolution. Currently, the model allows for the interaction between creep and fatigue damage. Simulation results will be presented that visualize creep and fatigue damage for hydrogen-fired and oxy-fuel airfoils. Additionally, the influence of dynamic changes in the TBC microstructure and phase composition with operational time will be discussed relative to all projected damage mechanisms.