Determination of parameters of an autonomous source of a constant magnetic field for a portable electromagnetic-acoustic transducer

• Дата: 2025
• Автори: Bolyukh, V. F., Suchkov, G. M., Mygushchenko, R. P., Kalnytskyi, M. E.
• Формат: Стаття
• Мова: English
• Опубліковано: National Technical University "Kharkiv Polytechnic Institute" and Аnatolii Pidhornyi Institute of Power Machines and Systems of NAS of Ukraine 2025
• Теми: autonomous magnetic field source; permanent magnet parameters; magnetic field; remote ferromagnetic object; integral criterion; electromagnetic-acoustic transducer; signal amplitude; noise
• Онлайн доступ: http://eie.khpi.edu.ua/article/view/333105
• Назва журналу: Electrical Engineering & Electromechanics

Purpose. Determination of rational parameters of an autonomous source of constant magnetic field, ensuring the efficiency of using portable electromagnetic-acoustic transducers (EMAT) for diagnostics of remote ferromagnetic objects. Methodology. An analysis of the parameters of an autonomous magnetic field source consisting of a permanent magnet and a ferromagnetic screen magnetizing a ferromagnetic object with a flat surface, providing a central magnetic field along the magnet axis above 0.3 T, was carried out. Results. The results of experimental studies on a sample of an autonomous source, which contained 6 sections of a permanent magnet made of NeFeB ceramics with dimensions of 50´50´10 mm3, correspond to the results of calculating the magnetic field on the surface of a ferromagnetic sample with an error of up to 9 %. Experimental studies were carried out for EMAT with two magnetic field sources containing rectangular permanent magnets of the same height but different widths. Novelty. It has been established that in order to select rational parameters of an autonomous source of magnetic field, it is necessary to use an integral criterion that takes into account the magnetic field in the surface layer of a ferromagnetic object, the magnetic scattering field, the volume of a permanent magnet, which determines the mass and size indicators and cost of the source, and the force of attraction to the ferromagnetic object. Practical value. For portable EMAT, increasing the magnetic field in a remote ferromagnetic object either by increasing the volume of a permanent magnet or by decreasing the air gap between the magnetic field source and the ferromagnetic object provides increased EMAT efficiency by increasing the ratio of the amplitude of the received ultrasonic bottom pulses to the noise amplitude. References 27, figures 14.