超声导波电磁声换能器的研究进展

摘要

Ultrasonic guided waves have been widely applied to the defect inspection of typical waveguide structures including plates and pipes because of their large area inspection capability and high efficiency.As one type of the transducer for ultrasonic guided waves inspection,electromagnetic acoustic transducers (EMAT) attracted wide attention and got rapid development.In this paper,the research progress of EMAT for ultrasonic guided waves inspection in the past twenty years was reviewed.Main contents include the following aspects:the structural design of the single-mode EMAT used in the ultrasonic guided waves inspection of plate-like and pipe structures;the configuration parameters optimization design of coil and magnet for improving the energy and the purity of guided wave modes,the configuration design of new type patch EMAT for non-metallic materials;and the application of array technique on the EMAT performance optimization and defect localization and imaging.%超声导波具有检测范围大、检测效率高等优点,广泛应用于板、管等典型波导结构的缺陷检测.作为超声导波换能器类型之一,电磁声换能器(electromagnetic acoustic transducer,EMAT)得到广泛关注和快速发展.综述了近20年来超声导波电磁声换能器的研究进展.主要包括:针对板和管结构超声导波检测的单模态EMAT结构设计;用于提高激励导波的能量和模态单一性的EMAT线圈与磁体结构参数的优化,针对非金属材料检测的新型贴片式EMAT的结构设计;阵列技术在EMAT性能优化上的应用和在缺陷定位和成像上的应用.