Radial wrinkles on film–substrate system induced by local prestretch: A theoretical analysis

The radial wrinkling of a stiff thin film lying on a compliant substrate triggered by local prestretch within a circular region is studied. The critical prestrain and wrinkle number are solved as functions of the radius of the prestretched region and the Young’s modulus ratio between the film and substrate. During post-buckling, the wrinkles may experience a secondary bifurcation and evolve into branching patterns.