摘要
电磁超声检测和电磁声发射检测都是通过电磁-应力耦合进行无损探伤.电磁声发射本质上是声发射,可以实时检测到缺陷的萌生、扩展及断裂过程.融合电磁声发射和电磁超声的复合检测方法大大提高了对金属微细裂纹定位的准确性,能够有效地避免噪声干扰和防止缺陷的漏检,相比单一检测方法和传统超声、声发射检测方法有显著优点.但电磁加载对激励源的输出要求很高,同时功率输出效率很低.为了提高电磁加载的输出效率及信噪比,设计了功率放大器与激励负载端之间的阻抗匹配电路,分析了加载电流频率、提离距离对激励线圈阻抗的影响.实验表明设计的阻抗匹配网络能有效提高电源的输出效率.
Electromagnetically-induced-acoustic emission(EMAE) and electromagnetic-acoustic testing(EMAT) are applied in nondestructive detection by the coupling of electromagnetic-stress. The essence of EMAE is acoustic emission, extension of the defects and fracture process can be detected in real time. Integrating these two kinds of electromagnetic nondestructive testing greatly improves the precision of the crack location and hence reduces false detection and residual detection. Comparing with the single detection and traditional ultrasonic, the integrating testing has significant advantages. However, the requirement on excitation amplitude of electromagnetic nondestructive testing is very high, but the efficiency of power is very low in the experiments. In order to increase the incentive efficiency of electromagnetic nondestructive testing and signal-to-noise ratio, the connection circuit between power amplifier and the load is designed. In this paper, the main influence of coil impedance is lift-off, and the distance of lift-off is analyzed in comparison. Experiments show that the design of impedance matching network can effectively improve the efficiency of the output power.
出处
《河北工业大学学报》
北大核心
2013年第6期1-6,共6页
Journal of Hebei University of Technology
基金
国家自然科学基金(51077036)
河北省自然科学基金(E2012202026
E2012202048)
