飞机多层结构铆钉周围裂纹脉冲涡流检测传感器参数优化

飞机多层结构铆钉周围埋藏裂纹检测是无损检测领域的一个难点和热点,脉冲涡流能够对这种裂纹进行有效的检测.针对这种缺陷检测,本研究采用了一种双激励线圈且用隧道磁电阻(TMR)为接收的新型探头.双激励源反向联接,激励电流不至于过大,但磁场却能达到局部聚焦的作用.通过大量试验对该传感器参数进行优化选择,以提高传感器的检测灵敏度.试验结果表明:当激励线圈绕制180 匝、两激励线圈间距为20~30 mm、单个线圈水平夹角为60°~90°、且TMR位于裂纹正上方时探头的检测灵敏度最大.该研究结果可为飞机多层结构铆钉周围裂纹脉冲涡流检测探头设计提供参考.

Optimization of Pulsed Eddy Current Sensor Parameters for Detection of Cracks around Rivet Sites in Multi-Layer Structure

Detection of the deeply embedded cracks around rivet sites in aircraft multi-layer structure is a difficulty and hotspot in the field of nondestructive testing. For the detection of this kind of defect, a kind of probe based on two exciting coil and TMR pick-up sensor has been designed in this paper. Two exciting coil were reversely-connected to produce a focused and intense magnetic field without the need of large current in the coil. A lot of experiments were done for selection of PEC sensor parameters to improve the detection sensitivity of the sensor. The experimental results showed that when the exciting coil winded as 180 turns, the spacing of two exciting coils was 20~30 millimeter, the angle between coil and horizontal was 60°~90°and the TMR sensor located above the crack, the detection sensitivity will reach maximum. This research provides reference for probe design in the cracks detection in aircraft multi-layer with PEC method.