Amplitude Characteristics of Acoustic Emission Signals Induced by Electromagnetic Exciting

The amplitude characteristics of electromagnetically induced acoustic emission (EMAE) are studied through the finite-element method (FEM) and validated by EMAE experiment. The deformation of a crack is calculated and analyzed by using FEM, and the deformation nature of the defect is determined by the fracture mechanics. The EMAE experiments under different exciting currents are carried out and the crack is located by acoustic emission (AE) signals. In addition, the calculated deformation and experimental AE signals are normalized. According to Kaiser effect and AE theory, the partly direct relationship between the acoustic emission signal and the calculated deformation can be obtained. This study provides crucial references for optimization analysis of EMAE. Meanwhile, the application of eddy current greatly reduces the demands of the power supply and improves the detection speed compared using the direct loading, which makes the engineering application of EMAE in possible.