飞机高锁螺栓孔边缺陷阵列远场涡流传感器仿真与试验

Simulation and experiment of array remote-field eddy current sensor for hole edge defect of aircraft high lock bolt

飞机高锁螺栓孔边隐藏缺陷的检测是航空无损检测领域中的难点,远场涡流检测技术不受集肤效应影响,对飞机高锁螺栓紧固件孔边隐藏缺陷检测具有极大优势。针对飞机高锁螺栓紧固件孔边缺陷的检测,设计研发了放置式阵列远场涡流传感器,建立了高锁螺栓孔边隐藏缺陷检测三维模型,优化了检测线圈中心与高锁螺栓中心放置距离,研究了阵列相邻通道间磁场薄弱区缺陷信号衰减趋势,采用阵列放置式的检测方式研究了不同尺寸缺陷检测信号特征。仿真与试验结果表明:检测线圈中心与高锁螺栓中心距离11 mm时检测灵敏度最佳;相邻通道间磁场薄弱区检测信号存在一定程度上的衰减,优化后的探头可检测埋深为4 mm、长×宽×深为5 mm×0.2 mm×2 mm的紧固件孔边隐藏缺陷,且随缺陷长度增大检测信号幅值呈上升趋势。

Detection of the hidden defect in the hole edge of aircraft high lock bolt is a difficulty in the field of aviation nondestructive testing.The remote field eddy current testing technology is not affected by the skin effect,and has great advantages in detection of hidden defects in the holes of fasteners of aircraft high lock bolts.For the remote field eddy current testing of hole edge defects of high lock bolt fasteners,an array remote field eddy current sensor is developed.A 3D model for detecting hole edge hidden defects of high lock bolts is established,and the placement distance between the detection coil center and the high lock bolt center is optimized.The attenuation trend of the signal of defect in the weak magnetic field between adjacent channels is then studied by adopting the detection method that array remote-field eddy current sensors are placed on the high lock bolt.Simulation and experimental results show that the detection sensitivity is the best when the distance between the center of the detection coil and the center of the high lock bolt is 11 mm.The detection signal of magnetic field weak area between adjacent channels attenuates to a certain extent.The optimized probe can detect hole edge hidden defects in fasteners with buried depth of 4 mm and length×width×depth of 5 mm×0.2 mm×2 mm.With the increase of the defect length,the amplitude of detection signal increases.