【作者】 季严松；

【导师】 赵子玉；

【作者基本信息】 上海交通大学 ， 高电压与绝缘技术， 2007， 硕士

【摘要】 稀土超磁致伸缩换能器是实现超声无损检测的超声波发生器的主要器件,其性能对无损检测的结果有重要的影响。使用有限元法对超磁致伸缩超声换能器的振动频率和磁场分布进行了计算,计算结果表明,前、后盖板振动的一阶模态频率与稀土棒的基频相互耦合,形成换能器共振频率为34kHz。稀土棒轴线上的磁场分布是比较均匀的。对换能器的线圈结构进行了优化,结果表明,本课题所设计的线圈结构可以用于换能器稀土棒的励磁。等效电路法是一种用来计算压电换能器的经典解析法。本课题使用等效电路法并结合傅立叶变换法对超磁致伸缩超声换能器进行了计算分析,并在此基础上开发了磁致伸缩换能器优化设计软件包一套。软件包在输入换能器的一些结构和材料参数后,就可以以数据和曲线形式给出计算结果。对换能器的预压力大小、电气结构参数以及几何结构尺寸进行了优化,从而为换能器的设计提供了理论指导。本文研制了平面型换能器,在小信号下测试了该换能器线圈的频响特性,在储能电容的大电流激励下测试了该换能器发射出的超声波波形,并将实测结果与计算结果作了比较和分析讨论,验证了计算结果的正确性。更多还原

【Abstract】 Rare earth giant magnetostrictive transducer is the ultrasonic generator for non-destructive testing. Its performance has important influence on the testing result.The vibration frequency and magnetic distribution of the transducer have been computed with the finite element method. The initial stress, electrical parameters and geometric dimensions have been optimized, which provides a theoretical guidance for the design of magnetostrictive transducer.Equivalent circuit method is a classical method used to calculate vertical vibration of piezoelectric transducer. Equivalent circuit method and Fourier Transform are used to calculate and analyze a GMM transducer in this research. On the basis of this research, a software package is developed for a GMM transducer design and optimization. After some structural and material parameters are inputted, characteristics of the transducer include data and curve will be given. A GMM transducer is optimized according to the software.A GMM transducer is developed is this research. The frequency response of the transducer and the real-time ultrasonic waveform of the transducer are measured. Compared with the experimental results, the calculated results are proved to be correct.更多还原