Mechanism and numerical simulation of electromagnetic acoustic emission based on short-time pulse and large current

To address the issue of traditional acoustic emission detection of tank bottom plate defects, which requires external force induction and exhibits low detection efficiency, it is proposed to utilize current excitation to investigate the sensitivity and feasibility of defect detection in tank bottom plates. This article employs the finite element method to establish an electromagnetic acoustic emission model and conducts numerical simulations of the electromagnetic field on a Q235 steel plate containing defects. The principle of electromagnetic acoustic emission effect excited by pulse high current is revealed, and the stress alternating law of defects under different current sizes, different plates, and different defect shapes is compared. The results show that the electromagnetic field can be effectively excited by the pulse current, and the electromagnetic acoustic emission (ae) signal can be induced at the defect site. The acoustic emission signal intensity is different from the current and the plate by comparing the stress alternation in the defect. The longer the defect shape is, the stronger the acoustic emission signal will be. The use of short-time pulse high current as an excitation method for electromagnetic acoustic emission has solved the problem of traditional acoustic emission that must detect defects under load, providing a technical means for acoustic emission crack detection of storage tanks, pipelines, and other metal equipment.