Yu Zheng-Yong, Zhu Shun-Peng, Liu Qiang, Liu Yunhan
Center for System Reliability & Safety, University of Electronic Science and Technology of China, Chengdu 611731, China.
Materials (Basel). 2017 May 8;10(5):513. doi: 10.3390/ma10050513.
As one of fracture critical components of an aircraft engine, accurate life prediction of a turbine blade to disk attachment is significant for ensuring the engine structural integrity and reliability. Fatigue failure of a turbine blade is often caused under multiaxial cyclic loadings at high temperatures. In this paper, considering different failure types, a new energy-critical plane damage parameter is proposed for multiaxial fatigue life prediction, and no extra fitted material constants will be needed for practical applications. Moreover, three multiaxial models with maximum damage parameters on the critical plane are evaluated under tension-compression and tension-torsion loadings. Experimental data of GH4169 under proportional and non-proportional fatigue loadings and a case study of a turbine disk-blade contact system are introduced for model validation. Results show that model predictions by Wang-Brown (WB) and Fatemi-Socie (FS) models with maximum damage parameters are conservative and acceptable. For the turbine disk-blade contact system, both of the proposed damage parameters and Smith-Watson-Topper (SWT) model show reasonably acceptable correlations with its field number of flight cycles. However, life estimations of the turbine blade reveal that the definition of the maximum damage parameter is not reasonable for the WB model but effective for both the FS and SWT models.
作为航空发动机断裂关键部件之一，准确预测涡轮叶片与轮盘连接部位的寿命对于确保发动机结构完整性和可靠性具有重要意义。涡轮叶片疲劳失效通常是在高温多轴循环载荷作用下产生的。本文针对不同失效类型，提出一种用于多轴疲劳寿命预测的新的能量临界平面损伤参数，实际应用中无需额外拟合材料常数。此外，对基于临界平面最大损伤参数的三种多轴模型在拉压和拉扭载荷作用下进行了评估。引入了GH4169在比例和非比例疲劳载荷作用下的实验数据以及一个涡轮盘 - 叶片接触系统的案例研究进行模型验证。结果表明，具有最大损伤参数的Wang - Brown（WB）模型和Fatemi - Socie（FS）模型的预测结果较为保守且可接受。对于涡轮盘 - 叶片接触系统，所提出的损伤参数和Smith - Watson - Topper（SWT）模型与实际飞行循环次数均呈现出合理的可接受相关性。然而，涡轮叶片寿命估计表明，最大损伤参数的定义对于WB模型不合理，但对FS模型和SWT模型均有效。
