Nickel based single crystal superalloys are predominantly used for turbine blades in aircraft engines and land based gas turbines. Understanding and predicting the fatigue failure of Ni based single crystal superalloys are critical to ensure the safety of these components during operation. In this paper, low cycle fatigue experiments were carried out to investigate cyclic deformation of a nickel based single cry stal superalloy MD2, recentlydeveloped by GE Power, with different crystallographic orientations. Specialty in situ scanning electron microscope (SEM) tests were also conducted to study the slip controlled initiation of short cracks under low cycle fatigu e. In particular, the stress strain responsefor both [001] and [111] orientations were used to calibrate a crystal plasticity model, which allowed us to simulate the activation of crystallographic slip systems and predict the initiation of short fatigue c rack. Using the accumulated shear strain as a criterion, the simulations confirmed that the slip system with the maximum accumulated shear strain appeared to control the crack initiation. The location and direction of slip traces and short cracks, captured by the crystal plasticity finite element simulations, agreed with the in situ2SEM observations. The modelling tool will be valuable for assessing the structural integritySEM observations. The modelling tool will be valuable for assessing the structural integrity of critical gas turbine blades.of critical gas turbine blades.

中文翻译：

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镍基单晶高温合金低周疲劳循环变形和裂纹萌生的晶体塑性有限元建模

镍基单晶高温合金主要用于飞机发动机和陆基燃气轮机的涡轮叶片。了解和预测镍基单晶高温合金的疲劳失效对于确保这些部件在运行过程中的安全至关重要。在本文中，进行了低周疲劳实验以研究 GE Power 最近开发的具有不同晶体取向的镍基单晶高温合金 MD2 的循环变形。还进行了专业原位扫描电子显微镜 (SEM) 测试，以研究低周疲劳下短裂纹的滑移控制引发。特别是，[001] 和 [111] 方向的应力应变响应用于校准晶体塑性模型，这使我们能够模拟晶体滑移系统的激活并预测短疲劳 c 齿条的开始。使用累积剪应变作为标准，模拟证实具有最大累积剪应变的滑移系统似乎控制了裂纹的萌生。晶体塑性有限元模拟捕获的滑移痕迹和短裂纹的位置和方向与原位2SEM观察结果一致。该建模工具对于评估结构完整性 SEM 观察结果很有价值。该建模工具对于评估关键燃气轮机叶片的关键燃气轮机叶片的结构完整性将是有价值的。模拟证实，具有最大累积剪切应变的滑移系统似乎控制了裂纹的萌生。晶体塑性有限元模拟捕获的滑移痕迹和短裂纹的位置和方向与原位2SEM观察结果一致。该建模工具对于评估结构完整性 SEM 观察结果很有价值。该建模工具对于评估关键燃气轮机叶片的关键燃气轮机叶片的结构完整性将是有价值的。模拟证实，具有最大累积剪切应变的滑移系统似乎控制了裂纹的萌生。晶体塑性有限元模拟捕获的滑移痕迹和短裂纹的位置和方向与原位2SEM观察结果一致。该建模工具对于评估结构完整性 SEM 观察结果很有价值。该建模工具对于评估关键燃气轮机叶片的关键燃气轮机叶片的结构完整性将是有价值的。该建模工具对于评估结构完整性 SEM 观察结果很有价值。该建模工具对于评估关键燃气轮机叶片的关键燃气轮机叶片的结构完整性将是有价值的。该建模工具对于评估结构完整性 SEM 观察结果很有价值。该建模工具对于评估关键燃气轮机叶片的关键燃气轮机叶片的结构完整性将是有价值的。