Study Of Endurance Life Predict For Turbine Blade With Film Cooling Hole

The directionally crystal nickel-based high-temperature alloy is used for the turbine blade of some advanced engines recently. In order to enhance the reliability of design parameters and design method for the endurance life of the turbine blade, the endurance life experiments are made on the specimens cut from the typical part of the turbine blades with film cooling hole including perpendicular-hole and nonperpendicular-hole.For each specimen, its endurance life and creep deformation values at different time are recorded during the endurance life experiment, and creep strains are gained. The experimental results show that the film cooling holes have a significant influence on endurance life compared with standard specimens' one. For 13 non-hole specimens, their endurance lives are much shorter than those of standard specimens. Their experimental results are very different even though at same nominal stress, but at least two data in every group (three specimens) are relatively close. For 6 specimens with holes, their endurance lives are very close, but all of them are even shorter than non-hole specimens, where the largest difference compared with standard specimens is up to 88%.To validate these experimental results, FEA simulation and fracture analysis is carried out. Since the number of the specimens is limited, the Norton creep law parameters which are transformed to the parameters in software ANSYS are gained usingθ-Project Concept method and nonlinear regression method. Moreover, the endurance life is obtained by computing the maximum stress value, then is compared with standard specimens' endurance life. The numerical simulation analysis demonstrates that the endurance life has significantly been influenced by the film cooling hole' Stress Concentration Effects, which should be adequately taken into account when predicting the turbine blade's endurance life. Additionally, fracture analysis shows that the second-phase particles which may become the source of crack make experimental data very different and the endurance life decreases very much.In this paper, the predicting equation is also obtained using modifiedθ-Project Concept, and its reliability is proved.