PSI - Issue 50

Alekseev D.I et al. / Procedia Structural Integrity 50 (2023) 17–26 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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The magnetic pulse methods can be divided into two groups according to the type of pressure formation in the sample: 1. Pulsed pressure mechanically transmitted to the sample by current carrying conductors – magnetic mechanical methods. 2. Pulse pressure is formed by the interaction of the magnetic field and induced current in the sample – magnetic induction methods.

Fig. 1. Magnetic pulse methods of mechanical testing conductive materials: a, b) loading of the samples with crack type macro defects; c) bending; d) spall; e) uniaxial tension; f) Hopkinson-Kolsky method; g) cylinder expansion; h) ring expansion. 1 – controlled current conductor, 2 – induced current conductor, 3 – sample, 4 – split Hopkinson-Kolsky pressure bar. An example of the first group is deformation of the test samples with crack-type macro defect under magnetic pressure forming by current carrying systems of the thin flat conductors placed inside the crack. As examples of the second group, following methods can be named: a. conducting ring expansion under the action of the pulse magnetic pressure of the spiral coil mounted inside the ring; b. tension of the wire fixed to the conductive disk under the action of the pulse magnetic pressure of the spiral coil placed near the disk. 3. Magnetic-mechanical methods During magnetic-mechanical loading, the pulse pressure on the sample is transferred through a tight mechanical contact with a loading device made of current-carrying elements in which magnetic pressure is formed. E.g., a magnetic-mechanical loading device is a system of two closely spaced flat conductors through which a counter current carry, see Fig. 2a. The loading device can be made in the form of a three-busbars (quasi-coaxial) system of conductors to avoid the effect of induced currents on the test specimen (heating, Lorentz force), see Fig. 2b.

Fig. 2. The magnetic pulse driver (MPD): a) two conductor system; b) three conductor system: Pm - forming magnetic pressure; c; c2 - MPD width; h; h2 - distance between MPD conductors; i(t) – electric current; B - induction of magnetic field.