Figure 9

Anelastic response of the solid at ρ = 0.99. A few strained configurations (ε = 0.016,0.028,0.036,0.048,0.060,0.064) are quenched suddenly to zero strain by rescaling the atomic coordinatesto study the relaxation of stress σ(t) over time t. The stress responds by first decreasing rapidly to a negative value whose magnitude increases with the initial ε and then slowly relaxing to zero from below. For the minimally strained solid, the relaxation is essentially exponential. If the initial strain is around ε*, the dynamical response shows a second relaxation which is complex and non-monotonic. The inset shows the dependence of the average stress σ_a during the relaxation process on the value of the initial ε before σ(t) decreases to 0. While σ_a grows linearly for small ε, its growth becomes rapid as ε crosses ε*.