结合国家对自主研发大客航空发动机的重大需求, 研究高温复杂变幅载荷下的航空发动机热端关键零部件寿命评估对重大装备安全服役具有重要的科学研究价值和工程实际意义。本项目结合多轴疲劳强度理论、材料强度理论，损伤力学、热固耦合有限元分析等对航空发动机涡轮盘结构件在高温热机多轴加载下的蠕变-疲劳损伤机制和热机多轴疲劳损伤机理进行系统的试验研究和定量的理论分析，研究出关键零部件寿命评估系统，为我国航空发动机结构强度设计和延寿提供技术基础。项目的研究主要内容包括: (1) 高温多轴蠕变与热机疲劳损伤机理研究；(2) 高温环境下高温合金结构材料多轴循环应力应变关系特性研究；(3) 高温多轴复杂载荷的循环计数方法研究；(4) 高温复杂多轴载荷下缺口件缺口危险部位局部应力应变确定方法的研究；(5) 高温热机载荷下多轴蠕变-疲劳损伤计算研究；(6) 航空发动机涡轮盘关键部位多轴蠕变-疲劳寿命评估系统研究。

Combined with the vital demand for self-developed airliner engines, the study of life assessment of key components under complex multiaxial variable amplitude loading at high temperature for the security service of major equipment has a great scientific value and practical engineering significance. In the project, multiaxial fatigue strength theory, strength theory of material, damage mechanics and thermal-solid coupling finite element analysis are combined to explore the creep-fatigue damage mechanisms for aeroengine turbine disk structure at high temperatures under thermomechanical multiaxial loading, to do quantitative theoretical analysis and experimental investigation, and to develop a life assessment system for the key components, which provide the technical basis for the structural strength design and life extension for aero-engine. The main contents of the study include: (1) study on the mechanism of multiaxial creep-fatigue damage and thermo-mechanical fatigue damage at high temperature; (2) relationship characteristic of multiaxial cyclic stress-strain for alloy structural materials under at high temperature; (3) cycle counting method under multiaxial complex loading at high temperature; (4) method for determining the local stress and strain at dangerous point for structural components under multiaxial complex loading at high temperature; (5) calculation of multiaxial creep-fatigue damage under complex thermomechanical loading at high temperature; (6) multiaxial creep-fatigue life assessment system for the key locations of aeroengine turbine disk at high temperature.