PSI - Issue 6

Yurii Meshcheryakov et al. / Procedia Structural Integrity 6 (2017) 146–153 Author name / Structural Integrity Procedia 00 (2017) 000 – 000

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a) b) Fig.6. Dimensions of shock-induced structural cells in 1565 Al. alloy (a) and 1561 Al. alloy (b). Now we are in position to compare the space period of oscillations L osc and mean size of the shock-induced structural elements L cell for each kind of alloy. By using the data of Table 1 one can calculate the space periods of oscillations. Comparison of space period of oscillations and dimensions of shock-induced cells yields: One can see that the space period of oscillations coincides with the mean size of shock-induced structural element for each kind of aluminum alloy. The coincidence of the space period of oscillations and dimension of structural elements indicates that resonance interaction of oscillations of the plastic flow and mesostructure can occur. The swinging of mesostructure under resonance is thought to be reason for transition of material into structure-unstable state. Due to difference in shock-induced structural elements for the studied alloys, the conditions for resonance between shock-induced elements and space dimensions of velocity oscillations happens at different impact velocities, which results in different values of threshold to heterogenization of structure. Acknowledgments This work is conducted in the frame of Russian Scientific Fund, Project No 17-11-01053. References Asay J.R. and Chhabildas L.C. 1981. Determination of the shear strength of shock-compressed 6061- T6 aluminum. In: ”Shock waves and High Strain- Rate Phenomena in Metals”. Concept and Applications. Eds. Marc Meyers and Lawrence E. Murr. Plenum Publishing Corporation, N. Y. Grady, D.E., Asay J.R. 1982. Calculation of thermal trapping in shock deformation of aluminum. J. Appl. Phys. 53. 7350.. Hinze J.O. 1959. Turbulence. N. Y. Mc. Graw Hill Inc., 680 pp. Indeitzev D.A., Meshcheryakov Yu. I.,. Kuchmin A.Yu., Vaviliv D.A. 2015. Multi-scale model of steady wave shock in medium with relaxation. Acta Mechanica. 226. 917-930. Meshcheryakov Yu.I., Divakov A.K. , Zhigacheva N.I., Makarevich I.P., Barakhtin B.K. 2008. Shock-induced structures in copper. Physical Review .B. 78. 64301 - 64316. Taylor J.W. 1965. Dislocation dynamics and dynamic yielding. J. Appl. Phys. 36, 3146-3150. 1. 1561 aluminum alloy: L osc = 250 µm; L cell = 260 µm. 2. 1565 aluminum alloy: L osc = 39 µm; L cell = 40 µm.