摘要
针对电磁超声技术检测铁磁材料中遇到的难题,从磁致伸缩效应的本构方程出发,讨论了在不同的磁场空间分布中,电磁超声传感器(Electromagnetic acoustic transducer,EMAT)的磁致伸缩效应对激励声波的贡献。为避免对磁致伸缩力的探讨,提出直接从弹性质点的位移方程中提取关于磁致伸缩效应的声波激励信息,而无须再计算弹性质点所受的体力。为验证这一理论的正确性,利用Matlab工具仿真具体的EMAT结构模型,分析位移方程的时空变化曲线,得到声波信息,与相关文献中用体力描述磁致伸缩效应的声波激励信息吻合,从而证明了这一理论的可行性。
In view of the electromagnetic ultrasonic testing technology problems encountered in ferromagnetic materials, the paper studies the contribution of magnetostrictive effect on exciting acoustic field according to the constitutive equation of the magnetostrictive effect. In order to avoid the discussion of magnetostrictive force, the process of exciting acoustic field based on magnetostrictive effect is directly analyzed from the elastic displacement equation, which makes it unnecessary to calculate the body force of elastic particles. A specific EMAT structure model is simulated in Matlab to verify the correctness of the theory. The simulation analyzes the time-space curves of displacement equation to calculate the acoustic filed. The results match with those got by describing magnetostrictive effect with magnetostrictive force on related papers, which verifies the feasibility of the theory proposed.
出处
《无损检测》
2015年第5期1-6,9,共7页
Nondestructive Testing
基金
国家重大科学仪器设备开发专项资助项目(2012YQ09017502)
关键词
电磁超声传感器
磁致伸缩效应
磁场空间分布
位移方程
Electromagnetic acoustic transducer
Magnetostrictive effect
Spatial distribution of magnetic field
Displacement equation
