Modulated electromagnetic field can excite ultrasonic field in metal structures, and at the crack peak, high frequency acoustic waves are generated and can be named as acoustic emission. The features of the wave can be influenced by the crack sizes, excitation signals, excitation voltage, etc. An experimental system was set up to study the correlation between signals and influencing factors. After building a model, the electric current field, electromagnetic forces field and deformation distribution field were obtained on ANSYS platform. Experiments were carried out to verify the validity and the repeatability. The high frequency component decoded from the AE waveforms represented the existence of the crack.
doi: 10.12783/SHM2015/7