Orientable wrinkles in stretched orthotropic films
Tensional wrinkles are widely observed in elastic thin films, with mono-orientation of wrinkles being usually perpendicular to the stretching direction. Here, by changing material orthotropic direction, we present orientable wrinkles in uniaxially stretched orthotropic membranes. To quantitatively explore orthotropy-related wrinkles and their morphological evolution, we develop a mathematical model by introducing orthotropic, elastic constitution into the extended F\"oppl-von K\'arm\'an nonlinear plate theory that can describe large in-plane anisotropic deformations.