CMX Lunch Seminar

Complex, high-frequency wrinkles characterize the shape of draped thin materials like cloth or plastic film. Unfortunately, simulating the formation of these wrinkles carries a steep computational cost: the shell must be discretized finely enough to resolve the wrinkle geometry, and the elastic energy governing wrinkle formation is non-convex (since wrinkles form as a consequence of buckling instability). I will present some of our preliminary work on a new model and algorithm for predicting the high-definition static shape of thin shells, including the fine wrinkles that arise in the interplay of tension and compression, using very coarse meshes with few degrees of freedom (100x fewer than is needed to resolve wrinkling at a similar scale using traditional shell elements). The main idea is to split the kinematics of the shell into degrees of freedom representing the coarse shape of the shell, which does not buckle in response to compression, and a wrinkle field, encoding the direction and frequency of the wrinkling. By analysing the physics of wrinkled, curved shells, we derive a principled expression for the reduced-order elastic energy of the wrinkle field. We validate our method on model problems from the physics literature, as well as on draped cloth garments.