Development of the hybrid numerical simulation to clarify shock viscosity effects in a plastic shock wave front

Abstract

Shock viscous stress can be defined as the stress differences between the stress on Rayleigh line and the equilibrium stress at the same strain. The shock viscous stress is one of the important parameters with respect to rising times of elastic and plastic shock wave fronts [1]. Swegle and Grady took the routine program of the shock viscous stress into their one-dimensional finite difference wave code, and they predicted the shock wave rise times occurred in several kind of materials with relatively small stress impacts [2]. Their numerical results seemed to represent the experimental results measured by the velocity interferometer system (VISAR). Strictly speaking, however, their method was not sufficiently accurate because their expression of the shock viscous stress was the stress differences between Rayleigh line and Hugoniot. Recently, we had proposed a new analytical method to get temperature in steady shock wave fronts and the effects were ascertained for a ceramic material and some metals [3, 4, 5, 6]. When we derive the temperature in shock wave fronts by our method, we can also get the quasistatic (equilibrium) stresses. Therefore, it is possible to obtain the shock viscous stress analytically. The structured variations in the shock wave rising process are closely related to the dissipative processes in the material, and it is interesting to investigate these structured characteristics.