项目面向航空发动机压气风扇叶片复杂受力条件下长寿命耐久性需求，针对重大工程装备核心零部件在实际工况中的多轴超高周疲劳损伤问题，基于超声频率谐振循环加载理论，开发可对十字形平板试件进行超声振动双轴加载的新型长寿命疲劳实验系统，实现参数化加载路径控制和测量信息闭合存储，形成一套高效可行的材料双轴超高周疲劳性能快速实验方法。项目还以双轴疲劳和超高周疲劳复合损伤机理为关键科学问题，利用新系统开展不同加载路径共计8组钛合金双轴超高周疲劳对比实验研究，借助先进微观组织特性表征和原位显微滑移线观测，建立双轴超高周低应力幅下物理意义更加明确的材料微纳尺度损伤与晶体参数及载荷的关系，揭示双轴超高周疲劳材料位错运动特点、损伤演化规律和缺陷萌生机制，形成考虑材料晶体学参数、加载路径和微观基本力学性能的双轴超高周疲劳损伤累积模型和寿命预测方法。项目的预期成果对高水平发展我国航空发动机等先进制造业具有重要意义

The project faces the change of long-life durability requirements on air fan blade for aero-engine under complex stress conditions. Major engineering equipment for the core component in encountered such problem of multiaxial high cycle fatigue damage in the actual working condition. Based on the theory of ultrasonic resonance frequency cyclic loading, this work aims to develop a new long-life fatigue experiment instruments for cruciform specimen under ultrasonic frequency biaxial loading, to realize parameterized closed loading path control and measurement information storage, and forming a set of realistic biaxial Ultra-high cycle fatigue test. As the composite of multiaxial fatigue and high cycle fatigue is the key scientific problem in this work, The Project also want to deal with the microstructure features with the help of advanced characterization and microscopic deformation. 8 groups of Ti-alloy specimen will be investigated under different loading paths with in-situ MO observation. The project tries to find out the relationship between the load and the action of dislocation with more explicit physical meaning and to establish a model of describing multiaxial high cycle fatigue damage cumulative and a life prediction method with the microscopic basic crystallographic parameters. The expected results of this project are of great significance to the high-end development of China's advanced manufacturing industries such as aero-engines.