飞机铆接结构的远场涡流传感器设计及试验研究

Design and Experimental Study of Far-field Eddy Current Sensor for Aircraft Riveted Structure

飞机的结构件在铆接时存在铆接误差与应力集中,且在疲劳载荷的作用下容易产生疲劳裂纹,影响飞机的飞行安全性。针对铆接结构的隐藏缺陷,现有技术难以检测,而远场涡流检测技术不受集肤效应的限制,对铆接结构缺陷的检测具有潜在优势。本研究对铆接结构的隐藏缺陷开展远场涡流检测试验研究,从远场涡流检测理论出发,研究激励/检测线圈距离、匝数与检测频率、灵敏度的关系,在此基础上优化远场涡流传感器的激励参数。结果表明:当激励线圈的匝数为1000,可感生出较强的涡流场;由于检测线圈采用的是差分形式,当检测线圈距离为7 mm时,检测信号幅值最大,且根据幅值特性或相位特性任一个信号,可准确对缺陷进行定位。

Due the riveting errors and stress concentrations existing,fatigue cracks are easily generated under the fatigue loads,which can affect the flight safety of the aircraft.However,the hidden defects of the riveted structure are difficult to detect using the current technology.The far-field eddy detection technology is not influenced by the skin effect,and has potential advantages for the detection of riveted structural defects.In this paper,the far-field eddy current detection experimental research is carried out on the hidden defects of the riveted structure.Based on the far-field eddy current detection theory,the relationship between the excitation/detection coil distance,the number of turns,and the detection frequency and sensitivity is studied.Then the xcitation parameters of eddy current sensor are optimized.The test results show that when the number of turns of the excitation coil is 1000,a strong eddy current field can be induced;because the detection coil uses a differential form,when the detection distance is 7 mm,the detection signal amplitude is the largest,and according to the amplitude Characteristics or phase characteristics,can accurately locate defects.