Analysis of electromagnetically induced acoustic emission under different magnetic field conditions

The ability of acoustic emission detection is enhanced by electromagnetic stimulation with external magnetic field. Different magnetic field directions, which are generated by permanent magnet, produce various vibrations of defect itself. In this paper, the deformation characteristics of electromagnetically induced acoustic emission (EMAE) are studied by the finite element method (FEM). The experimental data are compared by the signal reprocessing of sample entropy (SampEn), which under the condition of parallel and vertical magnetic field. The main conclusion is that characteristics of AE varied significantly under different magnetic field conditions, which provides crucial references for EMAE source. Meanwhile, this study leads to ratiocination that the application of parallel magnetic field reduces the demands of the power supply and improves the detection efficiency.