Figure 4: Coupled effect of outer boundary shape and radii ratio R_os/R_i on wrinkling characteristics of elliptic graphene annulus.

The wrinkle contours are colored based on the out-of-plane deformation under critical rotation angle ∆θ_c for annuli with varying (R_i, R_os, R_ol). (a–c) Annuli in group I have fixed R_i = 3 nm, R_os = 8 nm and varying R_ol = 8, 14, 20 nm, (d–f) group II have fixed R_i = 6 nm, R_os = 8 nm and varying R_ol = 8, 14, 20 nm, (g–i) group III have fixed R_i = 6 nm and same radii ratio R_os/R_i as group I. The annuli are divided into two symmetrical domains A and B which represent the area close to miner axis and major axis respectively.