叶片高低周复合疲劳试验技术研究

RESEARCH OF HCF/LCF COMBINED CYCLE FATIGUE EXPERIMENTAL TECHNIQUE FOR BLADE

为了验证叶片在高低周复合载荷作用下的疲劳寿命,建立了叶片高低周复合疲劳试验技术。基于圆柱滚子轴承和直线滑轨提出了正交载荷解耦方法,利用外部信号触发方式建立联合载荷协调加载控制技术。以某涵道尾桨风扇叶片为研究对象,开展其在离心载荷/低循环疲劳和气动载荷/高循环疲劳耦合作用下的疲劳试验。试验复合载荷控制精度优于±1%,同步协调加载时间间隔小于0.3 s。结果表明,提出的高低周复合疲劳试验技术有效地解决了叶片正交载荷解耦和协调加载控制等技术难点。为提高叶片类部件的高低周复合疲劳寿命预测精度提供技术支持。

To verify the fatigue life under high-low cycle combined loads of the blade the combined fatigue experimental technique was established.The orthogonal loads decoupling method was proposed based on the cylindrical rolled bearing and linear slide rail,and the coordinated loading control technique of a combined loads was presented by means of an external signal trigger.Then,the fatigue experiment of a certain type of ducted tail rotor fan blade under centrifugal load/Low Cycle Fatigue(LCF)and aerodynamic load/High Cycle Fatigue(HCF)was developed.The control precision of complex loads is superior to than±1%,and the coordinated loading time interval is less than 0.3 second.The experimental result indicates that the high-low cycle combined fatigue experimental technique can solve the technical problems of orthogonal loads decoupling and coordinated loading control,which provides the technical foundation for improving the high-low cycle combined fatigue life prediction precision of the blade.