Donut- and croissant-shaped microbuckles from experiments and numerical models

FIG. 5. (Color online) Comparison between three experimental and numerical shapes of the buckles for an atmospheric overpressure delta-p = 0.1 MPa, an internal radial compression stress sigma-0 = 321 MPa, and a folding angle β = 5 degrees.

(I think the “folding” angle is proportional to the amplitude of the delamination.)

From the same paper as the previous image

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