ICF13B

Fig. 7. Scheme of sample loading (q – loading, σ– the stretching stress) Fig. 8. The block-scheme of the setup for sinusoidal electromagnetic load of period 1 μs: Sample – a sample; IT – the pulse transformer; FL – the forming line; ED – the output device; HVW – a high-voltage electrode; PD – the photo diode; RC – a Rogovsky coil; OSC - an oscillograph The assessment of the radial force operating on a ring from rounds of the coil, was carried out by a technique stated in work [3], submitted on ICF 13. Tangential stretching stress was calculated on Laplace's formula for thin-walled covers ( ) ( ) , q t R t h σ = where − = q t F t c ( )/ ( ) the distributed radial loading acting on an internal surface of a ring, F (t) – force acting on a ring, c, R, h – width, internal radius and ring thickness, respectively. Fig. 9. General view of installation, 1 – solenoid; 2 – sample; 3 - Rogovsky coil, measuring current in the coil; 4 – Rogovsky coil, measuring current in a ring; 5 – photo diode; 6 – output device. Fig. 10. Oscillograms from the photo diode 1 and current from a Rogovsky coil 2. 6 3 4 5 1 2

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