Wrinkled membranes I: experiments

This paper presents a detailed experimental study of the evolution and shape of reversible corrugations, or wrinkles, in initially flat, linear-elastic and isotropic thin foils subject to in-plane loads.Two sets of experiments were carried out, on a rectangular membrane under simple shear and on a square membrane subjected to two pairs of equal and opposite diagonal forces at the corners.Salient findings are that: the wrinkle profile is generally well approximated by a half sine wave in the longitudinal direction, with constant or linearly-varying transverse wavelength; sudden changes in the shape of the membrane, accompanied by changes in the number of wrinkles, occur in both cases; in the sheared membrane the wrinkle pattern remains essentially unchanged for increasing shear displacement, whereas in the square membrane a large diagonal wrinkle appears when the corner load ratio is around 3.