电磁超声体波方法对内部孔洞缺陷检测研究

电磁超声是一种新型的超声检测方法，其具有非接触、不受工作环境影响、易于激发多种类型的超声波等优点。本文研究了电磁超声体波对结构件内部孔洞缺陷探测问题，首先利用离散点源实现对电磁超声声场的分析；而后利用有限元方法对电磁－结构多场耦合建模，研究超声体波在体内缺陷处的波型转换以及模式转换后爬波在缺陷表面传播情况；最后利用电磁超声体波对孔洞缺陷的尺寸、位置进行了定量检测。有限元计算结果与简化解析求解得到较好的验证，本文为电磁超声对体内孔洞缺陷的应用评估提供良好基础。

Research on Internal Hole-type Defect Detecting by Electromagnetic Ultrasonic Bulk Wave

Electromagnetic ultrasonic is a novel ultrasonic testing method, which has many advantages such as non￣contact,not affected by the environment and easy to excite various types of ultrasonic wave etc. This paper studies the ultrasonic detection internal hole￣type defects in metals using electromagnetic ultrasonic method. Firstly, the sound field of electromagnetic ultrasonic was analyzed which based on the discrete point source;secondly, a multiphysics finite element model based on electromagnetic field and structure field is build,not only the directly scattered bulk waves have been observed,but also the mode￣converted creeping waves on the defect surface;finally, the size and location of hole￣type defect were quantitative detecting. A simplified analytical solution was successfully applied to validate the simulation results. This paper has a solid foundation for the application of the internal hole￣type defect detecting by electromagnetic ultrasonic bulk wave.