电磁超声表面波辐射声场的三维有限元分析

为了得到电磁超声表面波换能器在被测试件表面和内部的辐射声场分布，采用ANSYS有限元仿真软件对电磁超声换能器辐射声场进行仿真.建立了电磁超声换能器三维有限元模型并进行了优化，给出了被测试件中感生涡流与换能器激励线圈参数的量化关系.通过电磁结构耦合的方法得到被测试件内部及表面不同方向质点的位移变化，分析了在被测试件内部的辐射声场分布，并给出了被测试件表面辐射声场的指向性规律.根据仿真模型搭建了电磁超声探伤平台，实验结果与指向角仿真结果基本吻合.实验结果表明：对电磁超声表面波辐射声场的有限元仿真，为其设计优化、实际探伤范围的确定、接收线圈放置位置，以及收发装置的安装角度提供了依据.

Three-dimensional finite element analysis on radiation sound field of electromagnetic ultrasonic surface wave

In order to obtain the distribution of radiation acoustic field generated at both surface and inner of measured specimen for electromagnetic ultrasonic surface wave transducer,ANSYS finite element simulation software was applied to simulate the radiation sound field of electromagnetic ultrasonic transducer.The three-dimensional(3D) finite element model for electromagnetic ultrasonic transducer was established,and the optimization was performed.And a quantitative relationship between the induced eddy current in the measured specimen and stimulating coil parameters of the transducer was derived.With the electromagnetic structural coupling method,the displacement variation of particles with different orientations at both surface and inner of measured specimen was obtained.The distribution of radiation sound field generated inside the measured specimen was analyzed,and the directionality rule of radiation sound field generated at the surface of measured specimen was given.In addition,an electromagnetic ultrasonic defect detection platform was established according to the simulation model.The experimental results are basically consistent with the simulated results for the direction angle.The results show that the finite element simulation on the radiation sound field of electromagnetic ultrasonic surface wave can provide the basis for the optimization of design,determination of practical defect detecting range,arrangement position of receiving coil as well as installation angle of sending and receiving devices.