“绝缘-导体”复合结构被广泛应用于工业各个领域,针对这类复合结构的检测需求,提出了一种切换式涡流-电容双模式无损检测技术,并研发了配套的检测系统。利用有限元仿真模型分析了双端激励双模式传感器的探测场特征,验证了双模式传感器对导体及绝缘体试样缺陷检测的可行性。针对两种模式下检出信号的特点设计了信号处理电路,主要包括正交锁相模块和信号放大与滤波模块,通过单片机输出信号控制多路复用结构实现了硬件电路切换。开发了检测系统软件,实现了控制信号和检测信号的传输与处理。以单片机主控电路为核心进行系统集成,形成了双模式检测系统,并进行了不同材料、不同结构的模拟缺陷试样扫描试验,试验结果表明,该系统具有良好的检测性能。

“Insulator-conductor” composite structures are widely used in various fields and in view of the testing needs of these structures, a dual-mode non-destructive testing system based on phase switching between capacitive and inductive modes was developed. The characteristics of the detection field of the planar coil sensor were analysed by using the finite element simulation model, and the feasibility of the dual-modality sensor for defect detection of conductor and insulator samples was verified. The signal processing circuit was designed according to the characteristics of the detected signals in the two modalities, and the hardware circuit switching was realized through a multiplexing structure. The software of the detection system was developed, which realized the program control mode and the acquisition and analysis of the data. The hardware and the software systems were integrated with the MCU main control circuit as the core, thereby forming the dual modality detection system. The scanning experiments of the composite structure samples were designed to verify the detection performance of the system.