涡轮叶片耦合疲劳寿命预测与试验验证

为了解决涡轮转子叶片在温度、离心力和气动/噪声联合载荷作用下的疲劳强度问题，开展了高低周复合载荷谱分解方法和基于高低周载荷的全时域蠕变损伤累积模型研究，提出了同时考虑蠕变损伤、低周疲劳损伤和高周疲劳损伤的耦合疲劳寿命预测方法。同时，通过正交载荷解耦和耦合载荷协调加载控制等关键技术的应用，开发了高温环境下的高低周复合疲劳试验平台。最终，基于设计的涡轮叶片模拟件，完成了耦合疲劳寿命预测和试验验证。结果表明:模拟试件的耦合疲劳寿命试验结果分散系数为1.01，耦合疲劳寿命的预测结果与试验结果偏差小于24%，从而验证了疲劳寿命预测模型的正确性，为我国航空发动机热端部件的疲劳强度设计和验证提供了有效的技术途径。 

Combined fatigue life prediction and experiment verification for turbine blade

In order to solve the fatigue strength problems of turbine rotor blade under the combined loads of temperature,centrifugal force and aerodynamic/acoustic,the decomposition method of a high-low cycle complex load spectrum and the full-time domain creep damage cumulative model based on the high-low cycle complex load were investigated.The combined fatigue life prediction method considering simultaneously the fatigue damage of creep,low cycle and high cycle was proposed.Meanwhile,the high-low cycle complex fatigue experiment platform was developed through application of the critical technologies,such as orthogonal loads decoupling and coordinated loading control of the complex load.Finally,taking a simulation specimen of a turbine blade as the research object,the combined fatigue life prediction and experiment verification were accomplished.Results showed that the scatter factor of experiment result of combined fatigue life was 1.01,and the deviation between the prediction result and the experiment result was less than 24%.The validity of fatigue life prediction model was verified,providing an effective technical approach to fatigue strength design and validation for aero-engine hot-end components.