Shock wave response of porous materials: from plasticity to elasticity

Shock wave reaction results in various characteristic regimes in porous materials. The geometrical and topological properties of these regimes are highly important in practical applications. Via morphological analysis of characteristic regimes with high temperature, we investigate the thermodynamics of shocked porous materials whose mechanical properties span a wide range from hyperplasticity to elasticity. It is found that, under fixed shock strength, the total fractional area A of the high-temperature regimes with T >= T-th and its saturation value first increase and then decrease with increasing initial yield sigma(Y0), where T-th is a given threshold value of temperature T. In the shock-loading procedure, the fractional area A(t) may show the same behavior if T-th and sigma(Y0) are chosen appropriately. Under the same A(t) behavior, T-th first increases and then decreases with sigma(Y0). At the maximum point sigma(Y0M), the shock wave contributes maximum plastic work. Around sigma(Y0M), two materials with different mechanical properties may share the same A(t) behavior even for the same T-th. The characteristic regimes in the material with larger sigma(Y0) are more dispersed.