Issue 49

Yu. Bayandin et alii, Frattura ed Integrità Strutturale, 49 (2019) 243-256; DOI: 10.3221/IGF-ESIS.49.24 254 Figure 10: Dependences of the stress amplitude versus the strain rate at the front of the shock wave for vanadium An explanation of the influence of the spatial-temporal dynamics of defects leading to the plastic strain instability (self- similar plastic wave fronts, adiabatic plastic shear) was proposed in [4, 34, 35], on the kinetics of spall failure in metals and ceramics in [22, 25]. The listed effects were studied theoretically on the basis of developed continuum models reflecting the role of metastability in the formation of collective modes and their relation to the relaxation properties of solid with defects. The results of the simulation are supported by original experiments that are used to identify the parameters and the results of the simulation to explain the self-similar features of deformation and fracture for metals and ceramics under shock wave loading. A CKNOWLEDGMENTS his work was supported by the Russian Foundation for Basic Research (project No. 17-01-00867). R EFERENCES [1] Barker, L.M. (1968). Behavior of dense media under high dynamic pressures, Gordon and Breach, New York. [2] Swegle, J.W., Grady, D.E. (1985). Shock viscosity and the prediction of shock wave rise times, J. Appl. Phys., 58(2), pp. 692-701. DOI: 10.1063/1.336184. [3] Grady, D.E. (2010). Structured shock waves and the fourth-power law, J Appl Phys, 107, pp. 013506. DOI: 10.1063/1.3269720. [4] Bayandin, Yu.V., Leontiev, V.A., Mikhailov, E.V., Naimark, D.O., Savinykh, A.S., Skakun, S.N. (2004). Experimental study of wave fronts and structural scaling in copper upon shock-wave loading, Phys. Mesomech., 7(1-2), pp. 97-101. [5] Naimark, O.B. (2003). Collective properties of defect ensembles and some nonlinear problems of plasticity and fracture, Phys. Mesomech., 6(4), pp. 39-63. 10 4 10 5 10 6 10 0 10 1 d  /dt, s -1  A , GPa V [33] V simulation d  /dt~  A 4 T