Experimental Check of E. I. Zababahin Hypothesis Concerning Limitation of Energy Cumulation in the Spherically Converging Shock-Wave Front in the Medium With Phase Transitions

Cumulation of a spherically converging shock wave in metals and its dependence on elastic-plastic properties, phase transitions, spall and shear fractures

“…Idealized representations were used for the description of the elastic-plastic deformation and phase transition in the material at which the infinite cumulation is absent when these waves converge to the center. The idea on the finite energy cumulation, developed by Zababakhin, further was confirmed by experimental investigations 11,12 in which the spherical-shock-waves-recovery-experiments allowed rather detailed study on how the cumulation character in the case of different-intensity stress waves convergence depends on real properties of materials.…”

“…In addition, a qualitatively correct relation is observed between the final dimensions of spheres and, respectively, the dimensions of cavities just as in experiments. 12,21 Certain differences in absolute values can be associated with the use of 1D approach in computations and with possible 3D losses as recorded in experiments. 22 Further advancement of the computational and theoretical description, as well as experimental techniques to diagnose different stages of phenomena under study seems reasonable.…”

“…Spheres made of iron, Steel 3, the quenched 30KhGSA steel (HRC = 35 · · · 40), and the 12Kh18N10T steel 11,12,[18][19][20][21][22] were investigated experimentally and theoretically. The diameters of these spheres were 40, 48, 60, 64, 166, and 184 mm.…”

“…For example, numerical simulation demonstrates that with the increase of the HE layer thickness due to the decrease in the diameter of the loaded iron sphere from 184 down to 166 mm in an appropriate explosive system, 12,21,22 mass of the molten central area in this sphere increases 15 times. This is associated with the fact that with the 184-mm diameter of the sphere, the elastic and phase precursors run far ahead the converging principal wave and the single-wave mode of particles loading fails to form while in the second case (Figs.…”

“…An increase in the mass of the molten central area is also due to the fact that with the 166-mm diameter of the sphere, the mass of the explosive grows and this leads to the increase in the plastic wave amplitude at deep radii. Figures 5 and 6 give the results of numerical simulation for experiments 12,18 with explosive loading of the 64-mm diameter spheres made of different materials. Figure 5(a) shows that in these experiments with samples of Steel 3 and the quenched 30KhGSA steel, the converging wave represents a three-wave configuration at medium radii and only one front is observed in the 12Kh18N10T steel.…”