飞机多层金属板隐藏缺陷远场涡流探头设计及试验研究

由于飞机多层金属板结构厚度大、复杂等特性,现有检测方法无法发现原位内部缺陷,对于多层板金属缺陷的检测一直都是航空无损检测的难题。远场涡流检测技术因打破趋肤效应的限制,涡流能量可穿透较厚的被测试件,对金属板结构中隐藏缺陷的检测具有潜在优势。该文针对飞机多层金属板隐藏裂纹的原位检测,建立多层金属板构件隐藏裂纹平面远场涡流检测有限元仿真模型,研究不同角度、不同深度裂纹检测幅值、相位的变化规律。为验证该仿真模型的正确性,开展远场涡流检测多层金属板的试验。试验结果表明:设计开发的远场涡流探头可检测埋深13 mm的裂纹缺陷,当裂纹倾斜角度为0°时,检测灵敏度最高,当裂纹倾斜角度为90°时,检测灵敏度最低,与仿真结果保持一致,且能够对缺陷进行精准定位,可为飞机多层金属板构件隐藏裂纹的定量检测提供依据。

Design and research of remote field eddy current probe based on defect detection of plane multilayer metal plates

The plane multilayer metal plate structure has larger thickness and complex structure.Conventional non-destructive testing methods are difficult to detect effectively in situ.However,the existing detection methods cannot find in-situ internal defects,and the detection of metal defects of multilayer boards has always been a problem of aviation non-destructive testing.Far-field eddy current testing technology breaks the limitation of skin effect,and eddy current energy can penetrate the thicker test piece,which has potential advantages for detecting hidden defects in the metal plate structure.In this paper,the in-situ detection of hidden cracks in aircraft multi-layer metal sheets is established.The finite element model of multi-plane metal plate member hidden defect plane far-field eddy current testing is established.The variation of detection amplitude and phase amplitude of cracks with different angles and depths is studied.In order to verify the correctness of the simulation model,an experiment of far-field eddy current testing multilayer metal plates was carried out.The experimental results show that the remote eddy current probe design can be used to detect the defects of 13 mm depth of the crack.The crack sensitivity of the detection angle of 0°is highest,the crack sensitivity of the detection angle of 90°is lowest.Consistent with simulation results,it takes effective measure to locate the defects accurately,and provides a basis for the quantitative detection of hidden cracks in aircraft multilayer metal plate components.