飞机铆接结构复杂隐藏缺陷的平面远场涡流检测方法研究

Several cases that a new battleplane failed in key components caused by hidden defects in riveted member during fatigue test have been found, as most parts of an aircraft body riveted with multi-layer aluminum alloy. However, a buried and complex hidden defect is difficult to detect based on existing technology..This project is to research a complex hidden defect in aircraft multi-layer aluminum alloy riveted components Planar Remote Field Eddy Current Testing (PRFECT) theory and quantitative evaluation about defecting. By knowing electromagnetic field distribution and signal transmission as well as attenuation characteristics of multimode detection probe in near or remote area, design a new probe to increase probe energy and optimize shielding unit, analyze PRFECT the detection mechanism. Then, we establish a PRFECT probe model and improve detection system, research the PRFECT detection method about complex defects in multi-layer riveted plate and signal properties, which combine with the verification in machining and dissecting complicated natural defects, and construct complex hidden defects with PRFECT parameters inversion optimization model. Afterward, we study the hidden defects of the partial occlusion riveted member PRFECT disturbance theory and optimization, and then construct inversion optimization model of compensation and correction to the partial occlusion disturbance effect, which achieves the quantitative evaluation theory and method of hidden defects..This project is of significance on the research and engineering application value to the nondestructive evaluation and reliability analysis of steel pipes. The result can be used in the security maintenance of ferromagnetic items in areas such as mechanics,special equipment,petrochemical industry, and so on.

飞机大量部件以多层铝合金铆接方式连接，已经发现数起新型战机在疲劳试验中因铆接构件隐藏缺陷导致关键部件失效的案例，而目前复杂隐藏缺陷现有技术难以检测。本项目旨在研究飞机铆接构件复杂隐藏缺陷的平面远场涡流检测（PRFECT）机理及缺陷量化评价方法。分析多模式检测探头的近/远场区电磁场分布及信号传递特性，优化探头能量增强及屏蔽单元并设计探头，剖析PRFECT法检测机理；建立PRFECT探头模型和完善检测系统，研究铆接构件复杂缺陷的PRFECT检测方法及辨识信号特征，建立复杂隐藏缺陷的PRFECT法多参量的缺陷反演模型；研究局部遮挡铆接结构的隐藏缺陷PRFECT扰动机理及优化，建立对局部遮挡干扰效应补偿修正的反演模型，提出隐藏缺陷定量评价理论和方法。. 本项目对飞机铆接构件的无损评价具有重要的理论研究意义和工程应用价值，研究成果可应用于航空航天、高铁等领域关键部件的安全维护。

飞机多层金属铆接构件属复杂结构件，其隐藏裂纹直接影响飞机机体的可靠性与安全性，而目前对于该类隐藏缺陷现有技术难以检测。本项目剖析了飞机多层金属铆接构件平面远场涡流检测技术机理，设计了平面远场涡流检测探头、新型常规涡流检测探头并进行相关优化及测试研究，研究了复杂构件隐藏缺陷评价方法并进行试验研究，研制了多通道平面远场及新型涡流检测仪，并制定了涡流检测技术成果标准，实现了针对复杂构件原位、快速以及精确的无损检测。.建立了复杂构件远场涡流及常规涡流三维有限元仿真模型，研究了激励线圈几何尺寸参数及磁路结构对磁场分布、能量传播的影响，分析了不同远场涡流探头屏蔽阻尼材料及组合方式的屏蔽性能。结合仿真结果，研制了适用于复杂构件隐藏缺陷检测的远场涡流探头以及新型涡流探头。. 提出了阵列远场涡流探头研究了不同缺陷长度和埋深对阵列探头各个通道检测信号的影响规律，通过峰值通道的检测幅值对各种复杂缺陷进行评价，提出了评价方法。开展了可靠性试验研究，建立了相关影响因素的POD曲线并对其结果进行分析，研究了角裂纹开裂位置、缺陷埋深以及检测人员等因素对POD建模的影响。.开发了基于FPGA的阵列远场涡流检测系统，搭建了阵列分时复用电路和仪器仪表放大电路等硬件系统，基于C++ MFC编写了阵列远场涡流检测软件，实现了对检测信号的波形显示。开发了基于ACFM法的测量系统，设计了由电源模块、激励模块等组成的硬件电路，基于LabVIEW编制了用于测量的上位机系统，实现了测量数据的实时显示和存储。.制定了无损检测云检测总则等多个涡流检测成果标准，为有关具体产品、设备、材料的无损检测标准或检测工艺规程的制定提供指导，为复杂构件深层隐藏缺陷涡流检测提供理论以及技术支撑。