PSI - Issue 39

Viktor Morozov et al. / Procedia Structural Integrity 39 (2022) 432–440 Author name / Structural Integrity Procedia 00 (2019) 000–000

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The thirst, low-voltage, version of the setup utilized a charge of the capacitor up to 20 kV and the high-voltage version utilized a pulse of 170 kV. In these experiments exploding copper wire with a diameter of 75 µm was placed in the 1..2 mm channel on the axis of the sample and vaporized with electric current propagating through it. The energy of expanding vaporization products (plasma) transfers to the sample and causes a cylindrical shock wave. This causes pulse loadings in the samples to propagate in the radial direction to the outer surface. The duration of these pulses depends on both electric current sample material properties. So, for the low-voltage version of setup we registered pulse with a duration of ~3 µs for PMMA samples and of ~2.5..3 µs for fluoroplastic samples. For high-voltage setups, these durations were therefore 1..1.5 µs and 3..5 µs. Characteristic current and mechanical pulse waveforms are provided in Fig. 3 and Fig. 4. The length of the samples was ~30 mm. Their diameters were 14..130 mm and 32.5..52 mm for PMMA samples for low- and high-voltage setups. For fluoroplastic, these diameters were therefore 10..68 mm and 12..20 mm.

Fig. 2. Low-voltage setup for experiments with cylinder samples: discharge switch (S), Tesla pulse transformer (IT), shaping line (FL), charge output device (ED), high voltage connector (HVW), exploding wire (EW), Rogovskii coli (current registration device) (RC), oscilloscope (OSC) and piezo probe (P).

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Fig. 3. Characteristic current and mechanical pulse waveforms registered with low-voltage setup for PMMA (a) and fluoroplastic (b) cylinder samples.

For experiments with lameles, we utilized only the low-voltage configuration of the generator (Fig. 5). The capacitor for these experiments was charged up to 18..24 kV. The thickness and length of the samples were 8 mm and