Figure 4.

The location of the maximum nominal compressive strain along the loading direction in the substrate when the wrinkling mode is sinusoidal. ${\epsilon }_{11,max}$ is a function of δ and δ_c in the case of no-pre-stretch. H(δ)≈0.18×2π/p in the fundamental state, which is largely insensitive to the compression δ. It should be mentioned that when the system has evolved into the period-doubling mode, the strain of the point shown in this figure is no longer the maximum strain in the substrate. (Online version in colour.)