Enhanced acoustic emission detection induced by electromagnetic stimulation with external magnetic field

The application of external magnetic field in the electromagnetically induced acoustic emission technique (EMAE) can enhance the ability of detecting the defects and reduce the stimulation current flow in the coil, due to the even bigger deformations generated by the enhanced Lorentz Force at the defects. In this paper, the finite element model of EMAE including an external magnetic field has been implemented based on the concrete experiment models. The sample's deformation has been analyzed when the exciting coil locates at different position. The results of experiments indicate that the defect itself can generate the modulated acoustic emission. That could be used to enhance detection ability of small cracks in the thin-walled metallic structures.