Figure 4.

Stretch history obtained by t_h = 10, t_h = 400, t_h = 1000, and t_h = 2000 (for 0–3000 sec). When t_h is small, the stretch history is nearly the same as the instantaneous stretch, and as t_h increases, stretch history reaches a plateau of λ = 1.5, the average stretch ratio of a random distribution in the range [1,2].