基于电涡流位移传感器的钛合金叶片振动疲劳试验研究

Experimental Study on Vibration Fatigue of Titanium Blades Using Eddy Current Displacement Sensor

为了研究钛合金叶片振动疲劳特性,基于电磁振动测试平台和非接触式电涡流位移传感器,开展了试验工装和试验程序设计。通过本文的传感器标定和振动应力标定方法研究,发展了基于电涡流位移传感器的非接触测量式钛合金叶片振动疲劳试验手段,进而完成了疲劳考核试验和裂纹扩展试验,研究了裂纹长度和固有频率随疲劳循环数累积的变化规律。试验结果表明,钛合金叶片具有较好的抗疲劳特性,疲劳裂纹萌生寿命较长,但裂纹扩展寿命较短。

In order to investigate the vibration fatigue characteristics of titanium alloy blades,experimental apparatus and procedures were designed on the basis of electromagnetic vibration platform and non-contact eddy current displacement sensor. Through the research of sensor calibration and vibration stress calibration methods in this paper,the non-contact-measuring vibration fatigue test method of titanium alloy blades based on eddy current displacement sensor was developed. Then,the fatigue stress experiment and crack propagation experiment were accomplished,where the variation laws of crack length and natural frequency with respect to accumulated fatigue cycles was studied. Experimental results demonstrate that the titanium alloy blades possess good fatigue resistance with relatively long fatigue crack initiation life. However,their fatigue crack propagation life was relatively short.