【作者】 张劼；

【导师】 杨庆新；

【作者基本信息】 河北工业大学 ， 电工理论与新技术， 2007， 硕士

【摘要】 电磁超声换能器(EMAT)是一种新型的超声波发射接收装置。因为无需与被测物接触,电磁超声换能器将传统的超声无损检测技术扩展到了高温、高速和在线检测中。同时,由于能够省略对被测物表面较为繁琐的预处理工作,电磁超声换能器显著提高了检测效率。然而电磁超声换能器本身换能效率低下,需要通过研究其原理并优化参数来改进提高换能效率。由于电磁超声换能器中的非线性问题及电磁-应力多场耦合问题十分复杂,采用传统的解析方法,难以分析研究电磁超声换能器的原理,因此本文在给出电磁超声换能器数学方程的基础上,建立了电磁超声换能器的物理模型,并用有限元手段来建模仿真。同时对电磁超声换能器几个主要参数进行分析,得出了各参数对电磁超声换能器影响的规律。更多还原

【Abstract】 The electromagnetic acoustic transducer (EMAT) is a new ultrasonic transmitting and receiving device. As no contact is required between the transducer and the test piece, the EMAT has extend traditional ultrasonic application into high-temperature, high-speed and on-line detection fields. In addition, without the necessity of a good surface condition, the time consuming and complicated preparation works of the test piece also can be omitted, and thus lead to a great improvement of the detection efficiency. However, the EMAT has the problem of low energy conversion, its principle should be studied and parameters should be optimized to improve the energy conversion rate. Because the EMAT’s nonlinear problems and electromagnetic– stress field coupling problem is very complex, it is difficult to analysis the EMAT’s principle using traditional analytical methods, thus this paper gives a EMAT’s mathematical model which is established on the basis of the EMAT’s mathematical equations, then models and simulates it by means of finite element methods. And also several major parameters of the EMAT are analysed, the law of every parameter impacted on the EMAT has obtained.更多还原