镍基单晶涡轮叶片气膜孔结构等寿命疲劳强度评估

For the structure of film cooling holes for aircraft engine turbine blades, the fatigue tests of specimens with film hole structure under different stress ratios were carried out. The fatigue limits under different stress ratios were obtained. The stress ratio-fatigue strength diagram at 107 equal life was drawn, and the data were fitted to obtain the ultimate strength of the film cooling hole structure, and the relationship between fatigue strength and stress ratio was obtained. The relationship was transformed into an equal life relationship of 107 under average-amplitude stress. The equal life curves under different equal life equations were compared and analyzed, and the difference of equal life law of film cooling hole structure was obtained. Comparing equal life data of film cooling hole structure with the 107 equal life curve of the material level, the influence of the hole structure on the equal life law of the nickel-based single crystal alloy was obtained. From the perspective of equal life analysis, the near-field stress around the hole was proposed as the reference value for the life assessment of the film cooling hole structure. To evaluate the fatigue life of film cooling hole structures from the perspective of equal life analysis, the new evaluation method was proposed using the near-field stress around the film cooling hole as the reference value.